Collis, Avinash, and Felix Eggers. 2020. “Effects of Restricting Social Media Usage.” SocArXiv. January 14. doi:10.31235/osf.io/udgxt
Abstract: Recent research has shown that social media services create large consumer surplus. Despite their positive impact on economic welfare, concerns are raised about the negative association between social media usage and performance or well-being. However, causal empirical evidence is still scarce. To address this research gap, we conduct a randomized controlled trial among students in which we track participants’ digital activities over the course of three quarters of an academic year. In the experiment, we randomly allocate half of the sample to a treatment condition in which social media usage is restricted to a maximum of 10 minutes per day. We find that participants in the treatment group substitute social media for instant messaging and do not decrease their total time spent on digital devices. Contrary to findings from previous correlational studies, we do not find any impact of social media usage on well-being and academic success. Our results also suggest that antitrust authorities should consider instant messaging and social media services as direct competitors before approving acquisitions.
Bipartisan Alliance, a Society for the Study of the US Constitution, and of Human Nature, where Republicans and Democrats meet.
Tuesday, January 14, 2020
People valorize the unproductive efforts of others in part because they believe such efforts reflect one’s inner virtues
Celniker, Jared, Andrew Gregory, Hyunjin Koo, Paul K. Piff, Peter
Ditto, and Azim Shariff. 2020. “The Moralization of Unproductive
Effort.” PsyArXiv. January 14. doi:10.31234/osf.io/nh9ax
Abstract: People believe that effort is valuable, but what kind of value does it confer? We find that displays of effort signal moral character. Importantly, we focus on displays of unproductive or unnecessary effort to highlight the heuristic nature of these intuitions—even “useless” effort is deemed virtuous. We conducted five studies to demonstrate the nature of these effects. In the domains of paid employment and charitable giving, the exertion of effort is deemed morally admirable (Studies 1-3) and is monetarily rewarded (Studies 1, 3, and 4), even when that effort results in no additional product. We test and find convergent patterns in a cross-cultural replication (Study 1b) and using a “big data” analysis of naturalistic donation behaviors (Study 4). We consider cultural and evolutionary accounts of effort moralization and discuss the implications of these effects for social welfare policy, automation, and the future of work.
General Discussion
Five studies, using multiple methodologies and cross-cultural samples, found that people ascribe greater moral value to greater exertions of effort, even when that effort is unproductive. Displays of effort serve as signals of one’s moral character, and these judgments inform decisions about how to allocate scarce monetary resources. People valorize the efforts of others in part because they believe such efforts reflect one’s inner virtues.
Our investigation refines previous research on effort evaluations and advances it in important ways. First, by explicitly controlling for productivity in our studies, we extend prior research (Amos, Zhang & Read, 2019) by showing that effort is valued even when it produces no value. Second, we provide the first discriminative evidence that effort cues affect moral evaluations specifically rather than positive character ascriptions more generally. Across four preregistered experiments, manipulating effort produced consistent differences in assessments of moral traits but not assessments of warmth or competence. These findings support theorizing that places moral character judgments at the center of impression formation (Goodwin, 2015; Uhlmann, Pizzaro & Diermeier, 2015). Finally, we broaden research on the martyrdom effect (Olivola & Shafir, 2013)—which has focused on manipulating one’s own commitment to a cause—by conceptually replicating it in paradigms focused on interpersonal moral judgments and real-world donation behaviors.
Unpacking Explanations of Effort Moralization
In addressing methodological limitations of prior work, limitations of a cultural explanation for effort moralization were also revealed. If PWE beliefs moralize effort, then inefficient effort should be denigrated because it is wasteful. Yet across our studies, participants consistently viewed unproductive effort as morally virtuous. Furthermore, individual differences
in participants’ work ethic beliefs did not moderate these effects, implying a limited role of PWE in explaining effort moralization. Finally, replicating one of our experiments in South Korea (including the failure of PWE beliefs to moderate valuations of effort) intimates that people moralize effort outside the West as well.
There is, in fact, some evidence that individuals in modern hunter-gatherer societies also moralize hard work (Smith & Apicella, 2019), suggesting that effort moralization may rest on more fundamental, and potentially evolutionary, origins. In the collaborative, group-living environments in which our species evolved, focusing on displays of costly signaling, like displays of effort, may have been an efficient and adaptive way to assess the cooperative intent of others (Gintis, Smith & Bowles, 2001). Partner choice markets can explain the use of competitive altruism as a signal of one’s value as a cooperation partner (Barclay, 2013), and effort may serve a similar function. This signaling account may provide a more parsimonious framework for conceptualizing effort moralization as a basic social heuristic. Rather than directly causing people to moralize effort, PWE beliefs may be scaffolded upon and exaggerate shared intuitions about the moral value of effort.
Cross-cultural replication of the current findings would seem a crucial next step in disentangling universal and culture-specific accounts of effort moralization. While South Korea is rooted in a distinct cultural tradition that has traditionally eschewed the overtly individualistic institutions and values of the U.S. (Hofstede, 1983), it is still a highly industrialized nation with some of the longest working hours in the OECD (OECD, 2019). Replications in societies that differ from the U.S. and South Korea on other dimensions would provide a more rigorous test of the role of culture in effort valuations.
Abstract: People believe that effort is valuable, but what kind of value does it confer? We find that displays of effort signal moral character. Importantly, we focus on displays of unproductive or unnecessary effort to highlight the heuristic nature of these intuitions—even “useless” effort is deemed virtuous. We conducted five studies to demonstrate the nature of these effects. In the domains of paid employment and charitable giving, the exertion of effort is deemed morally admirable (Studies 1-3) and is monetarily rewarded (Studies 1, 3, and 4), even when that effort results in no additional product. We test and find convergent patterns in a cross-cultural replication (Study 1b) and using a “big data” analysis of naturalistic donation behaviors (Study 4). We consider cultural and evolutionary accounts of effort moralization and discuss the implications of these effects for social welfare policy, automation, and the future of work.
General Discussion
Five studies, using multiple methodologies and cross-cultural samples, found that people ascribe greater moral value to greater exertions of effort, even when that effort is unproductive. Displays of effort serve as signals of one’s moral character, and these judgments inform decisions about how to allocate scarce monetary resources. People valorize the efforts of others in part because they believe such efforts reflect one’s inner virtues.
Our investigation refines previous research on effort evaluations and advances it in important ways. First, by explicitly controlling for productivity in our studies, we extend prior research (Amos, Zhang & Read, 2019) by showing that effort is valued even when it produces no value. Second, we provide the first discriminative evidence that effort cues affect moral evaluations specifically rather than positive character ascriptions more generally. Across four preregistered experiments, manipulating effort produced consistent differences in assessments of moral traits but not assessments of warmth or competence. These findings support theorizing that places moral character judgments at the center of impression formation (Goodwin, 2015; Uhlmann, Pizzaro & Diermeier, 2015). Finally, we broaden research on the martyrdom effect (Olivola & Shafir, 2013)—which has focused on manipulating one’s own commitment to a cause—by conceptually replicating it in paradigms focused on interpersonal moral judgments and real-world donation behaviors.
Unpacking Explanations of Effort Moralization
In addressing methodological limitations of prior work, limitations of a cultural explanation for effort moralization were also revealed. If PWE beliefs moralize effort, then inefficient effort should be denigrated because it is wasteful. Yet across our studies, participants consistently viewed unproductive effort as morally virtuous. Furthermore, individual differences
in participants’ work ethic beliefs did not moderate these effects, implying a limited role of PWE in explaining effort moralization. Finally, replicating one of our experiments in South Korea (including the failure of PWE beliefs to moderate valuations of effort) intimates that people moralize effort outside the West as well.
There is, in fact, some evidence that individuals in modern hunter-gatherer societies also moralize hard work (Smith & Apicella, 2019), suggesting that effort moralization may rest on more fundamental, and potentially evolutionary, origins. In the collaborative, group-living environments in which our species evolved, focusing on displays of costly signaling, like displays of effort, may have been an efficient and adaptive way to assess the cooperative intent of others (Gintis, Smith & Bowles, 2001). Partner choice markets can explain the use of competitive altruism as a signal of one’s value as a cooperation partner (Barclay, 2013), and effort may serve a similar function. This signaling account may provide a more parsimonious framework for conceptualizing effort moralization as a basic social heuristic. Rather than directly causing people to moralize effort, PWE beliefs may be scaffolded upon and exaggerate shared intuitions about the moral value of effort.
Cross-cultural replication of the current findings would seem a crucial next step in disentangling universal and culture-specific accounts of effort moralization. While South Korea is rooted in a distinct cultural tradition that has traditionally eschewed the overtly individualistic institutions and values of the U.S. (Hofstede, 1983), it is still a highly industrialized nation with some of the longest working hours in the OECD (OECD, 2019). Replications in societies that differ from the U.S. and South Korea on other dimensions would provide a more rigorous test of the role of culture in effort valuations.
We suggest greater aesthetic relevance, face for facial aesthetics, of the mobile and communicative parts for the female face and, conversely, of the rigid, structural, parts for the male one
Filtered beauty in Oslo and Tokyo: A spatial frequency analysis of facial attractiveness. Morten Øvervoll et al. PLOS, January 14, 2020. https://doi.org/10.1371/journal.pone.0227513
Abstract: Images of European female and male faces were digitally processed to generate spatial frequency (SF) filtered images containing only a narrow band of visual information within the Fourier spectrum. The original unfiltered images and four SF filtered images (low, medium-low, medium-high and high) were then paired in trials that kept constant SF band and face gender and participants made a forced-choice decision about the more attractive among the two faces. In this way, we aimed at identifying those specific SF bands where forced-choice preferences corresponded best to forced-choice judgements made when viewing the natural, broadband, facial images. We found that aesthetic preferences dissociated across SFs and face gender, but similarly for participants from Asia (Japan) and Europe (Norway). Specifically, preferences when viewing SF filtered images were best related to the preference with the broadband face images when viewing the highest filtering band for the female faces (about 48–77 cycles per face). In contrast, for the male faces, the medium-low SF band (about 11–19 cpf) related best to choices made with the natural facial images. Eye tracking provided converging evidence for the above, gender-related, SF dissociations. We suggest greater aesthetic relevance of the mobile and communicative parts for the female face and, conversely, of the rigid, structural, parts for the male face for facial aesthetics.
Hence, for the present study, we gathered evidence that forced-choice preferences when viewing specific SF bands of face images relate positively to preferences when viewing the corresponding broadband facial images. Our approach consisted in filtering spatial frequencies out of the natural face’s photo image (Fig 1). We then presented the obtained face images, containing a narrow band of SF information, in a “beauty contest” between same-sex face pairs (Fig 2). Although all of our photo images depicted faces of really existing European individuals, the participants of the present study belonged to different populations recruited in Europe and Asia (i.e., Norway and Japan).
The gender of the faces had a strong effect on which spatial frequencies were closest related to the same individuals’ decisions when performing the task with the unfiltered, natural looking, face pairs. That is, female faces related 80% of the time to choices made with the broadband faces, when viewing the highest of the four SF bands (Fig 3). In contrast, male faces related slightly above 80% of the time to choices made with broadband faces when viewing the second lowest of the four SF bands included in this study (Fig 3). We note that all of the SF bands related above 65% of time to choices made with broadband faces, indicating that all SF bands contribute to some extent with information relevant to aesthetics decision, although apparently in different doses. Thus, it would appear that medium-low spatial frequencies contains visual information that is most relevant for aesthetic decisions made about male faces, but the high spatial frequencies contain key information for decision about female faces. This dissociation is to our knowledge a novel finding, which could lead to identifying detailed gender-specific visual cues.
The oculomotor behavior provided converging evidence for the relevance of the medium-low spatial frequencies for male faces and high spatial frequencies for female faces. The attractive face in a pair was not only looked more in general than the unattractive, but gaze lingered the most over the attractive female face when the face pairs were shown with the highest (SF 4) filtering. Consistently, gaze dwelled the longest over the attractive male face when seeing the face pairs with the medium-low spatial (SF 2) filtering (Fig 4).
In addition, to get a sense of what information is contained and visible in the stimuli and within each band of SF information, we provided visualizations of how this content related to observers’ judgements. There was high similarity for the female faces between the two highest (SF 3 and 4) and the broadband faces within a small, bilateral, region (overlapping the eye pupil and the lower eyelid and infraorbital concavity but including the upper part of the zygomatic convexity; Fig 8). In addition, similarity between the filtered and unfiltered faces was higher for male models than female models for the area around the brows, nasal root, and eyes, and especially so for the (medium low) SF 2. Instead, for the medium high and high spatial frequencies (SF 3 and 4), the similarity was higher for female models than male models for the area around the lower eyelid and infraorbital region. Remarkably, the relative distributions of gaze when viewing these SF bands closely matched these similarity profiles.
Statistical analyses on the Lempel-Ziv complexity confirmed that the female faces contained significantly more information than the male faces in the above-described regions (Fig 9). However, information content was significantly high in the low SF bands only for the male faces; in particular, for the central eyebrow region, including the skull area immediately above (i.e., the supraorbital process or brow ridge) in SF 1, and the glabella of the nose and lowest nose region (including the nostrils) in SF 2.
Importantly, there was a striking dissociation between SFs for male and female faces in relation to the relevance of vertically oriented frequencies for attractiveness (normative) ratings. As visible in Fig 10, different spatial frequencies related to the ratings, revealing that for female faces, there was a significant positive correlation between attractiveness and amplitude of high vertical frequencies for female faces and at low vertical frequencies for male faces. Taking into consideration also the eye-tracking data, participants had a strong tendency to look at the faces along the whole axis of the nose (Fig 7), in particular in the European group, extending as low as the upper lip (philtum) and the Cupid’s bow at the center of the mouth, more so with increasing spatial frequency. This gaze behavior seems consistent with the preponderant role of the central, vertically oriented, features for attractiveness (normative) ratings.
Being the nose at the center of both the vertical and horizontal axes of the ‘face’ (Nota Bene: below the hairline, not the head), it is presumable that it constitutes an important element to focus gaze when evaluating facial proportions, the configuration and global harmony or symmetry of the face [58]. When spatial frequency is high, the volumetric aspect of the nose, relatively more relevant for the male face (Fig 11, right panel), becomes less visible. The nose is the most sexually dimorphic facial trait in its morphology, being on average disproportionally larger in volume in male than female faces [85–87]. While the visibility of the nose’s volume decreases that of its shape and symmetry increases with higher spatial frequencies and the latter features appear more relevant for judging the attractiveness of the female faces (Fig 11, left panel). Since gaze scanning (Fig 7) revealed a strong tendency to focus gaze at the root of the nose, or onto the central portion of the face that may correspond to the limiting size for efficient summation of configurational properties of upright (vertically oriented) face information in a single configurational face template [88]. The eyes, being paired features, horizontally centered together with the vertical prominence of the nose [89], may also convey essential information on a face’s proportions and symmetry, and more clearly so in higher spatial frequencies conditions.
It also seems of interest that the dispersion of gaze over the eyes, nose and mouth region differs in our European and Asian groups (Fig 7). The typical T-shaped focus pattern appears mainly with the European participants and increasingly so with higher spatial frequencies. In fact, the pattern of fixations is consistent with previous reports that Asians (i.e., Chinese) tend to look less at the eyes and distribute less their gaze over the face [90–92]. Especially within Japanese culture, a prolonged eye contact may be disrespectful and Japanese children are taught to look at others’ necks instead of the eyes [93, 94].
Perhaps the most remarkable dissociation between female and male features related to attractiveness, revealed by the present study’s Fourier approach, is between the two faces in Fig 11. These show graphic representations of the spatial frequencies that correlate positively with the stimuli’s normative attractiveness ratings (collected independently of the present eye-tracking study and only with Norwegian raters). A striking difference between the two genders’ images is that they show very different, little overlapping, SF components. Moreover, these SF components impressively overlap with the SF bands most relevant for forced choices, derived from the present eye-tracking study (Fig 3). For the male face (Fig 11, right panel), the attractiveness-correlated SF provide only a coarse visual resolution of the face, which however clearly conveys the depth or volumetric aspect of the head and face, with its overall size, extent of the face contour (the jaw and chin), and skull’s bone structure. These three-dimensional aspects of the male’s whole face or skull structure may be important in judging overall proportions. In contrast, the female face’s (in Fig 11, left panel) attractiveness-correlated SFs, not only show little overlap with the male’s, but they suggest that female attractiveness may be judged more on information carried by higher spatial frequencies. These may reveal local information about the surface of the face and of specific features at a level of detail that is optimal also for the task of individual person recognition and the communication of emotional signals.
In particular, internal features of the female face like the brow ridge, eyes, mouth, as well as the lower part of the face contour or chin, and their immediately surrounding facial surface regions, are clearly visible in the left panel image. We surmise that the high resolution of the above traits allows a more precise evaluation of the arrangements, spatial relations, or distance ratios between these features (e.g., the inter-ocular distance). There are several suggestions in the literature on facial beauty (also from anthropology, odontology, and aesthetic medical surgery) that our sense of face attractiveness may seek a “golden ratio” between facial traits like the eyes and mouth/teeth and the general proportions of the face ([95] but see [96]). We surmise that at HSF resolutions, information is optimal for spotting the presence of skin blemishes and the smoothness surface skin (i.e., cues of age or poor health) as well as details of the eye region affording the registering of subtle differences in eyelids’ and orbital region shape. If smooth skin is crucial for attractiveness in female faces and these properties of surface skin are best represented in high spatial frequencies, then amplitudes of higher frequencies should correlate with attractiveness ratings, since these frequencies make visible these aspects. We also note that the irises’ colors as well as the size of the pupils seem clearly delineated at such resolution. Instead, the colors of the irises would be smeared at LSF and, interestingly, previous research suggests that eye color may be more relevant when judging female than male faces for attractiveness [13]. Similarly, the highly mobile pupils may be particularly important for signaling social agreeableness, interest and attraction [8, 97]. We note that our behavioral and gaze results in the main experiment seem consistent with this ideas.
Moreover, the lower portion of the nose (nostrils) and the fullness of the lips (or vermilions) appear clearly visible within these attractiveness-correlated spatial frequencies and shape imperfections and coloring, luminance contrast between sides of the Cupid’s bow, may be very salient at this high resolution. Thus, female faces’ attractiveness-related SFs may reveal subtle deformations over the face surface, skin, and be related to the soft and malleable elements of the face, instead of its rigid skull structure. These highly mobile parts of the face like the mouth, eyes and eyebrows, all allow the display of subtle affiliative emotions [98], which may also play a key role when judging the attractiveness of an individual, even when just looking at static images [72].
In the male image in Fig 11 (right panel), a region around the ocular orbits, including the eyebrows and the bony area immediately above (i.e., the supraorbital process or ridge and glabella), as well as a region below the eyes and cheeks’ zygomas, appears well delineated in volumetry. Interestingly, the lower portions of the nose and of the mouth’s upper region play a role for male attractiveness, despite at such a coarse level of resolution the separations between the nostrils or lips are not resolved. Instead, the three-dimensional or volumetric aspects of the chin (in particular the protuberance of the mandible and its breadth) appear to be very salient. A possibility is that the coarse LSF prevalence in the image, by revealing the bony prominence of the brow ridge and of the jaw and chin, conveys effectively the attribute of masculinity inherent in the face [62, 99, 100]. In addition, a large face size characterizes masculinity as opposed to femininity [101]. However, several researchers have cautioned that masculinity may predict attractiveness relatively weakly compared to other fluctuating properties like skin color [102–104] or face and body symmetry [105, 106], which signal immunocompetence. Said and Todorov [18] found a gender-specific dissociation in the effects of shape (e.g., face width) or reflectance (e.g., lightness and color of skin). Increases towards masculinity in reflectance aspects of the male face increased attractiveness, but doing the same in shape aspects decreased it. We surmise that despite the coarse LSF male image (in Fig 11) both the reflectance of skin and of the brows are clearly visible. Interestingly, the reflectance dimensions with the strongest effects on female attractiveness involved the contrast around the eyes and the redness of the lips, which may be both best visible at higher SF.
Indeed, the HSF prominence in the image of the female face’ in Fig 11 yields a more detailed but somewhat less volumetric rendition (with slightly “embossed” features to use an art metaphor). What is visible appears related not only to highly mobile parts of the face that allow the display of subtle affiliative emotions but also to several cues associated with a sense of femininity [107, 108]. Sexual dimorphism correspond to different directions in morphometric space [108] and the female direction is associated with horizontal reduction of the chin, a forward movement of the gonion (jaw angle) and alveolar prognathism. In Fig 11, the male chin is clearly more visible than the female and appears larger in the morphed image.
The eye-tracking results confirmed that the beautiful faces are strong attractors of attention [109], since participants spent about 10% more time dwelling onto the attractive face in a pair (Fig 5) than on the relatively less attractive one. It has been shown that the attentional priority towards attractive faces can also occur unconsciously [110] and that a decision about a face’s level of attractiveness can be reached very rapidly (within 33 ms), and not very differently than when having unlimited time [111]. However, the present results are consistent with several previous studies showing that we typically spend extra time looking at faces considered attractive [112–114].
Finally, a previous study [38] used Fourier power spectrum analyses to describe the relation between spatial frequency and power of the radially averaged (1d) Fourier spectrum on a log-log scale. As the researchers point out, most natural (complex) images show a linear relationship and the relative strength or ‘power’ of fine detail information or coarse structure in an image can be, respectively, expressed linearly be the angle of the slopes in the power plots. Importantly, enhanced HSF information leads to shallow slopes, whereas enhanced LSF information leads to steep slopes. Given that pleasing natural scenes and artworks share a shallow power slope of -2 [115], the authors hypothesized that also faces approaching a Fourier power slope of -2 (i.e., with enhanced HSF information) would be considered more attractive than the same face, or others, differing from this value (e.g., steeper slopes between -3 and -4). Remarkably, when participants were given the opportunity to manually adjust the Fourier slope of the images on screen, they did choose a mean value of -2.6, which is a bit closer to that of pleasing natural scenes or artistic facial portraits. The effect was significantly larger for female faces, which also seems consistent with the present study’s findings of a bias for HSF information for female faces. A limitation of the Fourier slope approach is that it is informative about the relative distribution of frequency power, but not specific frequency bands. We surmise that, by presenting ranges of SF information separately, we are likely to reveal which information contained in the natural stimulus directly related to the aesthetic judgment about a face. In contrast, by strengthening or adding one type of visual information by distorting the natural image, one can reveal directional biases and explore the limits within which a face’s attractiveness can be enhanced [17].
Abstract: Images of European female and male faces were digitally processed to generate spatial frequency (SF) filtered images containing only a narrow band of visual information within the Fourier spectrum. The original unfiltered images and four SF filtered images (low, medium-low, medium-high and high) were then paired in trials that kept constant SF band and face gender and participants made a forced-choice decision about the more attractive among the two faces. In this way, we aimed at identifying those specific SF bands where forced-choice preferences corresponded best to forced-choice judgements made when viewing the natural, broadband, facial images. We found that aesthetic preferences dissociated across SFs and face gender, but similarly for participants from Asia (Japan) and Europe (Norway). Specifically, preferences when viewing SF filtered images were best related to the preference with the broadband face images when viewing the highest filtering band for the female faces (about 48–77 cycles per face). In contrast, for the male faces, the medium-low SF band (about 11–19 cpf) related best to choices made with the natural facial images. Eye tracking provided converging evidence for the above, gender-related, SF dissociations. We suggest greater aesthetic relevance of the mobile and communicative parts for the female face and, conversely, of the rigid, structural, parts for the male face for facial aesthetics.
Discussion
A key question about what constitutes our sense of aesthetics is what kind of visual information within the stimulus underlies our judgements. Despite the spatial frequency structure of any visual stimulus is processed very early by the visual brain and several studies have addressed its role in the identification of facial identity and/or expression [81, 82], very few studies have specifically investigated the role of visual spatial frequency information in supporting our sense of facial aesthetics. That different face relevant types of visual information can be optimally channeled through different bands of spatial frequencies is well known for emotional expressions, but the possibility that a similar relationship occur for aesthetic cues has not been fully explored yet. It is very likely that other facial information, seemingly unrelated to visual spatial frequency, plays a relevant role in judgments of attractiveness (e.g., skin’s tone [83, 84]), but spatial frequency may play a role beyond the coding of facial shape. In particular, the optimal perception of several of surface and texture cues may be confined within specific bands of spatial information (e.g., the thin lines or creases revealing age or the colors of small parts like the irises). The appreciation of the colors (or discoloring) of small-width or thin facial parts (like the mouth lips) may also depend on high frequency information that may be smeared and significantly weakened in visibility at low spatial frequencies.Hence, for the present study, we gathered evidence that forced-choice preferences when viewing specific SF bands of face images relate positively to preferences when viewing the corresponding broadband facial images. Our approach consisted in filtering spatial frequencies out of the natural face’s photo image (Fig 1). We then presented the obtained face images, containing a narrow band of SF information, in a “beauty contest” between same-sex face pairs (Fig 2). Although all of our photo images depicted faces of really existing European individuals, the participants of the present study belonged to different populations recruited in Europe and Asia (i.e., Norway and Japan).
The gender of the faces had a strong effect on which spatial frequencies were closest related to the same individuals’ decisions when performing the task with the unfiltered, natural looking, face pairs. That is, female faces related 80% of the time to choices made with the broadband faces, when viewing the highest of the four SF bands (Fig 3). In contrast, male faces related slightly above 80% of the time to choices made with broadband faces when viewing the second lowest of the four SF bands included in this study (Fig 3). We note that all of the SF bands related above 65% of time to choices made with broadband faces, indicating that all SF bands contribute to some extent with information relevant to aesthetics decision, although apparently in different doses. Thus, it would appear that medium-low spatial frequencies contains visual information that is most relevant for aesthetic decisions made about male faces, but the high spatial frequencies contain key information for decision about female faces. This dissociation is to our knowledge a novel finding, which could lead to identifying detailed gender-specific visual cues.
The oculomotor behavior provided converging evidence for the relevance of the medium-low spatial frequencies for male faces and high spatial frequencies for female faces. The attractive face in a pair was not only looked more in general than the unattractive, but gaze lingered the most over the attractive female face when the face pairs were shown with the highest (SF 4) filtering. Consistently, gaze dwelled the longest over the attractive male face when seeing the face pairs with the medium-low spatial (SF 2) filtering (Fig 4).
In addition, to get a sense of what information is contained and visible in the stimuli and within each band of SF information, we provided visualizations of how this content related to observers’ judgements. There was high similarity for the female faces between the two highest (SF 3 and 4) and the broadband faces within a small, bilateral, region (overlapping the eye pupil and the lower eyelid and infraorbital concavity but including the upper part of the zygomatic convexity; Fig 8). In addition, similarity between the filtered and unfiltered faces was higher for male models than female models for the area around the brows, nasal root, and eyes, and especially so for the (medium low) SF 2. Instead, for the medium high and high spatial frequencies (SF 3 and 4), the similarity was higher for female models than male models for the area around the lower eyelid and infraorbital region. Remarkably, the relative distributions of gaze when viewing these SF bands closely matched these similarity profiles.
Statistical analyses on the Lempel-Ziv complexity confirmed that the female faces contained significantly more information than the male faces in the above-described regions (Fig 9). However, information content was significantly high in the low SF bands only for the male faces; in particular, for the central eyebrow region, including the skull area immediately above (i.e., the supraorbital process or brow ridge) in SF 1, and the glabella of the nose and lowest nose region (including the nostrils) in SF 2.
Importantly, there was a striking dissociation between SFs for male and female faces in relation to the relevance of vertically oriented frequencies for attractiveness (normative) ratings. As visible in Fig 10, different spatial frequencies related to the ratings, revealing that for female faces, there was a significant positive correlation between attractiveness and amplitude of high vertical frequencies for female faces and at low vertical frequencies for male faces. Taking into consideration also the eye-tracking data, participants had a strong tendency to look at the faces along the whole axis of the nose (Fig 7), in particular in the European group, extending as low as the upper lip (philtum) and the Cupid’s bow at the center of the mouth, more so with increasing spatial frequency. This gaze behavior seems consistent with the preponderant role of the central, vertically oriented, features for attractiveness (normative) ratings.
Being the nose at the center of both the vertical and horizontal axes of the ‘face’ (Nota Bene: below the hairline, not the head), it is presumable that it constitutes an important element to focus gaze when evaluating facial proportions, the configuration and global harmony or symmetry of the face [58]. When spatial frequency is high, the volumetric aspect of the nose, relatively more relevant for the male face (Fig 11, right panel), becomes less visible. The nose is the most sexually dimorphic facial trait in its morphology, being on average disproportionally larger in volume in male than female faces [85–87]. While the visibility of the nose’s volume decreases that of its shape and symmetry increases with higher spatial frequencies and the latter features appear more relevant for judging the attractiveness of the female faces (Fig 11, left panel). Since gaze scanning (Fig 7) revealed a strong tendency to focus gaze at the root of the nose, or onto the central portion of the face that may correspond to the limiting size for efficient summation of configurational properties of upright (vertically oriented) face information in a single configurational face template [88]. The eyes, being paired features, horizontally centered together with the vertical prominence of the nose [89], may also convey essential information on a face’s proportions and symmetry, and more clearly so in higher spatial frequencies conditions.
It also seems of interest that the dispersion of gaze over the eyes, nose and mouth region differs in our European and Asian groups (Fig 7). The typical T-shaped focus pattern appears mainly with the European participants and increasingly so with higher spatial frequencies. In fact, the pattern of fixations is consistent with previous reports that Asians (i.e., Chinese) tend to look less at the eyes and distribute less their gaze over the face [90–92]. Especially within Japanese culture, a prolonged eye contact may be disrespectful and Japanese children are taught to look at others’ necks instead of the eyes [93, 94].
Perhaps the most remarkable dissociation between female and male features related to attractiveness, revealed by the present study’s Fourier approach, is between the two faces in Fig 11. These show graphic representations of the spatial frequencies that correlate positively with the stimuli’s normative attractiveness ratings (collected independently of the present eye-tracking study and only with Norwegian raters). A striking difference between the two genders’ images is that they show very different, little overlapping, SF components. Moreover, these SF components impressively overlap with the SF bands most relevant for forced choices, derived from the present eye-tracking study (Fig 3). For the male face (Fig 11, right panel), the attractiveness-correlated SF provide only a coarse visual resolution of the face, which however clearly conveys the depth or volumetric aspect of the head and face, with its overall size, extent of the face contour (the jaw and chin), and skull’s bone structure. These three-dimensional aspects of the male’s whole face or skull structure may be important in judging overall proportions. In contrast, the female face’s (in Fig 11, left panel) attractiveness-correlated SFs, not only show little overlap with the male’s, but they suggest that female attractiveness may be judged more on information carried by higher spatial frequencies. These may reveal local information about the surface of the face and of specific features at a level of detail that is optimal also for the task of individual person recognition and the communication of emotional signals.
In particular, internal features of the female face like the brow ridge, eyes, mouth, as well as the lower part of the face contour or chin, and their immediately surrounding facial surface regions, are clearly visible in the left panel image. We surmise that the high resolution of the above traits allows a more precise evaluation of the arrangements, spatial relations, or distance ratios between these features (e.g., the inter-ocular distance). There are several suggestions in the literature on facial beauty (also from anthropology, odontology, and aesthetic medical surgery) that our sense of face attractiveness may seek a “golden ratio” between facial traits like the eyes and mouth/teeth and the general proportions of the face ([95] but see [96]). We surmise that at HSF resolutions, information is optimal for spotting the presence of skin blemishes and the smoothness surface skin (i.e., cues of age or poor health) as well as details of the eye region affording the registering of subtle differences in eyelids’ and orbital region shape. If smooth skin is crucial for attractiveness in female faces and these properties of surface skin are best represented in high spatial frequencies, then amplitudes of higher frequencies should correlate with attractiveness ratings, since these frequencies make visible these aspects. We also note that the irises’ colors as well as the size of the pupils seem clearly delineated at such resolution. Instead, the colors of the irises would be smeared at LSF and, interestingly, previous research suggests that eye color may be more relevant when judging female than male faces for attractiveness [13]. Similarly, the highly mobile pupils may be particularly important for signaling social agreeableness, interest and attraction [8, 97]. We note that our behavioral and gaze results in the main experiment seem consistent with this ideas.
Moreover, the lower portion of the nose (nostrils) and the fullness of the lips (or vermilions) appear clearly visible within these attractiveness-correlated spatial frequencies and shape imperfections and coloring, luminance contrast between sides of the Cupid’s bow, may be very salient at this high resolution. Thus, female faces’ attractiveness-related SFs may reveal subtle deformations over the face surface, skin, and be related to the soft and malleable elements of the face, instead of its rigid skull structure. These highly mobile parts of the face like the mouth, eyes and eyebrows, all allow the display of subtle affiliative emotions [98], which may also play a key role when judging the attractiveness of an individual, even when just looking at static images [72].
In the male image in Fig 11 (right panel), a region around the ocular orbits, including the eyebrows and the bony area immediately above (i.e., the supraorbital process or ridge and glabella), as well as a region below the eyes and cheeks’ zygomas, appears well delineated in volumetry. Interestingly, the lower portions of the nose and of the mouth’s upper region play a role for male attractiveness, despite at such a coarse level of resolution the separations between the nostrils or lips are not resolved. Instead, the three-dimensional or volumetric aspects of the chin (in particular the protuberance of the mandible and its breadth) appear to be very salient. A possibility is that the coarse LSF prevalence in the image, by revealing the bony prominence of the brow ridge and of the jaw and chin, conveys effectively the attribute of masculinity inherent in the face [62, 99, 100]. In addition, a large face size characterizes masculinity as opposed to femininity [101]. However, several researchers have cautioned that masculinity may predict attractiveness relatively weakly compared to other fluctuating properties like skin color [102–104] or face and body symmetry [105, 106], which signal immunocompetence. Said and Todorov [18] found a gender-specific dissociation in the effects of shape (e.g., face width) or reflectance (e.g., lightness and color of skin). Increases towards masculinity in reflectance aspects of the male face increased attractiveness, but doing the same in shape aspects decreased it. We surmise that despite the coarse LSF male image (in Fig 11) both the reflectance of skin and of the brows are clearly visible. Interestingly, the reflectance dimensions with the strongest effects on female attractiveness involved the contrast around the eyes and the redness of the lips, which may be both best visible at higher SF.
Indeed, the HSF prominence in the image of the female face’ in Fig 11 yields a more detailed but somewhat less volumetric rendition (with slightly “embossed” features to use an art metaphor). What is visible appears related not only to highly mobile parts of the face that allow the display of subtle affiliative emotions but also to several cues associated with a sense of femininity [107, 108]. Sexual dimorphism correspond to different directions in morphometric space [108] and the female direction is associated with horizontal reduction of the chin, a forward movement of the gonion (jaw angle) and alveolar prognathism. In Fig 11, the male chin is clearly more visible than the female and appears larger in the morphed image.
The eye-tracking results confirmed that the beautiful faces are strong attractors of attention [109], since participants spent about 10% more time dwelling onto the attractive face in a pair (Fig 5) than on the relatively less attractive one. It has been shown that the attentional priority towards attractive faces can also occur unconsciously [110] and that a decision about a face’s level of attractiveness can be reached very rapidly (within 33 ms), and not very differently than when having unlimited time [111]. However, the present results are consistent with several previous studies showing that we typically spend extra time looking at faces considered attractive [112–114].
Finally, a previous study [38] used Fourier power spectrum analyses to describe the relation between spatial frequency and power of the radially averaged (1d) Fourier spectrum on a log-log scale. As the researchers point out, most natural (complex) images show a linear relationship and the relative strength or ‘power’ of fine detail information or coarse structure in an image can be, respectively, expressed linearly be the angle of the slopes in the power plots. Importantly, enhanced HSF information leads to shallow slopes, whereas enhanced LSF information leads to steep slopes. Given that pleasing natural scenes and artworks share a shallow power slope of -2 [115], the authors hypothesized that also faces approaching a Fourier power slope of -2 (i.e., with enhanced HSF information) would be considered more attractive than the same face, or others, differing from this value (e.g., steeper slopes between -3 and -4). Remarkably, when participants were given the opportunity to manually adjust the Fourier slope of the images on screen, they did choose a mean value of -2.6, which is a bit closer to that of pleasing natural scenes or artistic facial portraits. The effect was significantly larger for female faces, which also seems consistent with the present study’s findings of a bias for HSF information for female faces. A limitation of the Fourier slope approach is that it is informative about the relative distribution of frequency power, but not specific frequency bands. We surmise that, by presenting ranges of SF information separately, we are likely to reveal which information contained in the natural stimulus directly related to the aesthetic judgment about a face. In contrast, by strengthening or adding one type of visual information by distorting the natural image, one can reveal directional biases and explore the limits within which a face’s attractiveness can be enhanced [17].
Overall effect of music training programs in cognitive & academic benefits is consistently null, regardless of the type of outcome measure (verbal, non-verbal, speed-related, etc.)
Sala, Giovanni, and Fernand Gobet. 2020. “Cognitive and Academic Benefits of Music Training with Children: A Multilevel Meta-analysis.” PsyArXiv. January 15. doi:10.31234/osf.io/7s8wr
Abstract: Music training has repeatedly been claimed to positively impact on children’s cognitive skills and academic achievement. This claim relies on the assumption that engaging in intellectually demanding activities fosters particular domain-general cognitive skills, or even general intelligence. The present meta-analytic review (N = 6,984, k = 254, m = 54) shows that this belief is incorrect. Once the study quality design is controlled for, the overall effect of music training programs is null (g ̅ ≈ 0) and highly consistent across studies (τ2 ≈ 0). Small statistically significant overall effects are obtained only in those studies implementing no random allocation of participants and employing non-active controls (g ̅ ≈ 0.200, p < .001). Interestingly, music training is ineffective regardless of the type of outcome measure (e.g., verbal, non-verbal, speed-related, etc.). Furthermore, we note that, beyond meta-analysis of experimental studies, a considerable amount of cross-sectional evidence indicates that engagement in music has no impact on people’s non-music cognitive skills or academic achievement. We conclude that researchers’ optimism about the benefits of music training is empirically unjustified and stem from misinterpretation of the empirical data and, possibly, confirmation bias. Given the clarity of the results, the large number of participants involved, and the numerous studies carried out so far, we conclude that this line of research should be dismissed.
Abstract: Music training has repeatedly been claimed to positively impact on children’s cognitive skills and academic achievement. This claim relies on the assumption that engaging in intellectually demanding activities fosters particular domain-general cognitive skills, or even general intelligence. The present meta-analytic review (N = 6,984, k = 254, m = 54) shows that this belief is incorrect. Once the study quality design is controlled for, the overall effect of music training programs is null (g ̅ ≈ 0) and highly consistent across studies (τ2 ≈ 0). Small statistically significant overall effects are obtained only in those studies implementing no random allocation of participants and employing non-active controls (g ̅ ≈ 0.200, p < .001). Interestingly, music training is ineffective regardless of the type of outcome measure (e.g., verbal, non-verbal, speed-related, etc.). Furthermore, we note that, beyond meta-analysis of experimental studies, a considerable amount of cross-sectional evidence indicates that engagement in music has no impact on people’s non-music cognitive skills or academic achievement. We conclude that researchers’ optimism about the benefits of music training is empirically unjustified and stem from misinterpretation of the empirical data and, possibly, confirmation bias. Given the clarity of the results, the large number of participants involved, and the numerous studies carried out so far, we conclude that this line of research should be dismissed.
Whole-apple intake was associated with a reduced risk of CVD mortality, ischemic heart disease mortality, stroke mortality, all-cause mortality, and severe abdominal aortic calcification
The effects and associations of whole-apple intake on diverse cardiovascular risk factors. A narrative review. Berner Andrée Sandoval-Ramírez et al. Critical Reviews in Food Science and Nutrition, Jan 13 2020. https://doi.org/10.1080/10408398.2019.1709801
Abstract: Apples are among the world’s most consumed fruits. However, while the impact of whole-apple intake on cardiovascular disease (CVD) remains unknown. This narrative review summarizes a novel integrated view of whole-apple intake, CVD risk association (through observational studies; OSs), and the effects on CVD risk factors (randomized trials; RTs). In 8 OSs, whole-apple intake was associated with a reduced risk of CVD mortality, ischemic heart disease mortality, stroke mortality, all-cause mortality, and severe abdominal aortic calcification, as well as with lower C-reactive protein (CRP) concentrations. In 8 RTs, whole-apple consumption reduced total cholesterol, low-density lipoprotein cholesterol, systolic blood pressure, pulse pressure, and plasma inflammatory cytokines, and noticeably reduced CRP, whereas it increased high-density lipoprotein cholesterol (HDLc) and improved endothelial function. Thus, consuming between 100 and 150 g/day of whole apples is associated with a lower CVD risk and decreases in blood pressure, pulse pressure, total cholesterol, low-density lipoprotein cholesterol, and inflammation status as well as with increases in HDLc and endothelial function. These results, support the regular consumption of whole apples as an aid in the prevention of CVD.
Keywords: Apple, blood pressure, cardiovascular, cholesterol, health
Abstract: Apples are among the world’s most consumed fruits. However, while the impact of whole-apple intake on cardiovascular disease (CVD) remains unknown. This narrative review summarizes a novel integrated view of whole-apple intake, CVD risk association (through observational studies; OSs), and the effects on CVD risk factors (randomized trials; RTs). In 8 OSs, whole-apple intake was associated with a reduced risk of CVD mortality, ischemic heart disease mortality, stroke mortality, all-cause mortality, and severe abdominal aortic calcification, as well as with lower C-reactive protein (CRP) concentrations. In 8 RTs, whole-apple consumption reduced total cholesterol, low-density lipoprotein cholesterol, systolic blood pressure, pulse pressure, and plasma inflammatory cytokines, and noticeably reduced CRP, whereas it increased high-density lipoprotein cholesterol (HDLc) and improved endothelial function. Thus, consuming between 100 and 150 g/day of whole apples is associated with a lower CVD risk and decreases in blood pressure, pulse pressure, total cholesterol, low-density lipoprotein cholesterol, and inflammation status as well as with increases in HDLc and endothelial function. These results, support the regular consumption of whole apples as an aid in the prevention of CVD.
Keywords: Apple, blood pressure, cardiovascular, cholesterol, health
Crimes that were written in a foreign language were systematically evaluated as less severe, maybe due to attenuated emotional processing in a nonnative language
Woumans, E., Van der Cruyssen, I., & Duyck, W. (2020). Crime and punishment: Morality judgment in a foreign language. Journal of Experimental Psychology: General. Jan 2020. https://doi.org/10.1037/xge0000736
Abstract: The current study examined whether use of a foreign language affects the manner in which people evaluate a criminal situation. We employed a range of crime scenarios, for which severity judgment scores were obtained. Crimes that were written in a foreign language were systematically evaluated as less severe compared with the same cases described in the native language. We propose that these differences may be due to attenuated emotional processing in a nonnative language. Crucially, this observed variation in severity judgment may also affect magistrates and police interrogators confronted with crime scenarios formulated in a foreign tongue. This in turn would have inevitable consequences for the penalty they will or will not exact on the suspect.
Abstract: The current study examined whether use of a foreign language affects the manner in which people evaluate a criminal situation. We employed a range of crime scenarios, for which severity judgment scores were obtained. Crimes that were written in a foreign language were systematically evaluated as less severe compared with the same cases described in the native language. We propose that these differences may be due to attenuated emotional processing in a nonnative language. Crucially, this observed variation in severity judgment may also affect magistrates and police interrogators confronted with crime scenarios formulated in a foreign tongue. This in turn would have inevitable consequences for the penalty they will or will not exact on the suspect.
Discussion
The goal of the present study was to identify whether use of a foreign language
influences crime judgment. Our results show that a crime is indeed deemed less severe
when it is described in a language other than the native one. This was the case for all four
murder scenarios employed in this study, making it the first demonstration ever that
crime judgment is affected by language use. Hence, the outcome of our study is
imperative for actual administration of justice in a globalised world, where suspects,
juries, and judges often have different native languages than the official language of the
jurisdiction in which they live.
Previous research on juridic judgment had already established that judges are
prone to certain bias when it comes to crime assessment. As such, attractiveness and
facial characteristics of the offender seem to determine the verdict and stringency of the
sentence. Attractive individuals and individuals with large and round eyes, high
eyebrows, and a narrow chin (i.e. baby-faced) tend to be judged less severely, an effect
which has been observed in lab settings (e.g. Berry & Zebrowitz-McArthur, 1988; Efran,
1974; Leventhal & Krate, 1977) as well as in field studies (e.g. Stewart, 180; 1985;
Zebrowitz & McDonald, 1991). Although these findings are striking, personal
appearance may be deemed a more plausible determinant of judgment than the language
employed. Intuitively, one would conceive that accounts of a crime are visualised in a
juror’s mind, creating a scenario independent of language. Nevertheless, similar findings
have been reported within the literature on moral decision-making (Costa et al., 2017).
Here, the prevailing theory ascribes the effect to emotional attenuation as a result of
foreign language processing. Still, it may also be the case that use of a foreign language
reduces vividness of mental imagery (Hayakawa & Keysar, 2018), which in turn may
hamper emotional processing. In any case, moral dilemmas involve personal harm for the
respondents, as they are the ones deciding on matters of life and death. The current
research now shows that the foreign language effect persists, even if a third person is the
agent of the scenario and the respondent is merely a ‘bystander’.
Although the foreign language effect was observed systematically, our study is
characterised by the fact that our crime cases varied in both motive and feelings of
remorse. Furthermore, we noticed that narratives in which the agent was male were rated
more gravely, both by male and female participants. It may be the case that crimes
committed by men are judged as more appalling than crimes committed by women.
Conversely, it is possible that gender and severity coincidentally coincided.
Notwithstanding, we believe that neither explanation alters the key finding of this study,
namely the impact of foreign language use. Moreover, this may be regarded as a
validation that the effect of language is persistent and does not depend on specific story
characteristics. This being said, we must also point out that our participant sample
consisted of both sexes, but was still dominantly female (86%). Previous research has
demonstrated that females may be more ethically sensitive than males (e.g. Roxas &
Stoneback, 2004). We must therefore note that the general outcome of this study could
vary if the sample consists of only males, who may be less severe in their judgment.
Nevertheless, there is again no indication that this may influence the effect of language
reported here. Furthermore, as the materials in this study were transferred into the other
language using the method of back-translation by a non-native speaker, future work may
need to determine whether materials written by native speakers would affect text
perception, be it emotionally or otherwise.
All in all, our findings indicate that use of a foreign language diminishes crime
severity judgment, and whilst our study was conducted among laypeople, evidence from
field studies into judgment bias related to the appearance of offenders suggests that our
results may extrapolate to professionals. Crucially, the observed variation in morality
standards may also affect magistrates and police interrogators confronted with crime
scenarios formulated in a foreign tongue, who will consider these cases to be less severe
than they would in their native one. This in turn would have inevitable consequences for
the penalty they will or will not exact on the suspect. To illustrate, in the case of the
European Court of Human Rights, the working language is either English or French.
These are the languages in which judges deliberate, pleadings and written legal
submissions are translated, and the judgment is drafted. As this court often deals with
important cases such a prohibition of torture, right to life, and right to liberty and
security, it would have serious repercussions if judges were to underestimate the gravity
of the situation merely due to the language being used. Naturally, this is not the sole
example. In an increasingly multilingual society (Grosjean, 2012), judges and juries all
over the world may be operating in a non-native language.
Oxytocin administration can promote self‐serving lying when given repeated opportunities to lie; sensitivity to these effects might be moderated by individual differences in the oxytocin receptor gene
The role of oxytocin on self‐serving lying. Cornelia Sindermann, Ruixue Luo, Benjamin Becker, Keith M. Kendrick, Christian Montag. Brain and Behavior, January 13 2020. https://doi.org/10.1002/brb3.1518
Abstract
Introduction The effects of intranasal administration of the neuropeptide oxytocin on social cognition and behavior are highly specific. Potentially situational and personal variables influence these effects. The aim of the present study was to investigate effects of oxytocin administration on self‐serving lying, including situational effects.
Methods A total of 161 adult males participated in a randomized double‐blind placebo‐controlled between‐subject intranasal oxytocin administration (24 international units) study. Self‐serving lying was assessed using three subsequent rounds of the die‐in‐a‐cup paradigm, in which different degrees of lying can be implemented by the participants that can be determined on group level.
Results Oxytocin administration seemed to promote self‐serving lying, particularly in the third (last) round and only to a certain degree (not to the maximum possible).
Conclusions Our findings demonstrate that oxytocin administration can promote self‐serving lying when given repeated opportunities to lie. Moreover, exploratory results presented in the Supplementary Material indicate that the sensitivity to the effects of intranasal oxytocin in this domain might be moderated by individual differences in the oxytocin receptor gene.
Abstract
Introduction The effects of intranasal administration of the neuropeptide oxytocin on social cognition and behavior are highly specific. Potentially situational and personal variables influence these effects. The aim of the present study was to investigate effects of oxytocin administration on self‐serving lying, including situational effects.
Methods A total of 161 adult males participated in a randomized double‐blind placebo‐controlled between‐subject intranasal oxytocin administration (24 international units) study. Self‐serving lying was assessed using three subsequent rounds of the die‐in‐a‐cup paradigm, in which different degrees of lying can be implemented by the participants that can be determined on group level.
Results Oxytocin administration seemed to promote self‐serving lying, particularly in the third (last) round and only to a certain degree (not to the maximum possible).
Conclusions Our findings demonstrate that oxytocin administration can promote self‐serving lying when given repeated opportunities to lie. Moreover, exploratory results presented in the Supplementary Material indicate that the sensitivity to the effects of intranasal oxytocin in this domain might be moderated by individual differences in the oxytocin receptor gene.
Individuals living under gang control have significantly worse education, wealth, and less income than individuals living only 50 meters away in areas not controlled by gangs
Melnikov, Nikita and Schmidt-Padilla, Carlos and Sviatschi, Maria Micaela, Gangs, Labor Mobility, and Development (October 29, 2019). SSRN: http://dx.doi.org/10.2139/ssrn.3477097
Abstract: We study the effects that two of the largest gangs in Latin America, MS-13 and 18th Street, have on economic development in El Salvador. We exploit the fact that the emergence of gangs in El Salvador was in part the consequence of an exogenous shift in US immigration policy that led to the deportation of gang leaders from the United States to El Salvador. Using the exogenous variation in the timing of the deportations and the boundaries of the territories controlled by the gangs, we perform a spatial regression discontinuity design and a difference-in-differences analysis to estimate the causal effect that living under the rule of gangs has on development outcomes. Our results show that individuals living under gang control have significantly worse education, wealth, and less income than individuals living only 50 meters away in areas not controlled by gangs. None of these discontinuities existed before the arrival of gangs from the US. The results are not determined by exposure to violence, lower provision of public goods, or selective migration away from gang locations. We argue that our findings are mostly driven by gangs restricting residents' mobility and labor choices. We find that individuals living under the rule of gangs have less freedom of movement and end up working in smaller firms. The results are relevant for many developing countries where non-state actors control parts of the country.
Keywords: Gangs, Development, Latin America, MS-13, Crime, Mobility
Abstract: We study the effects that two of the largest gangs in Latin America, MS-13 and 18th Street, have on economic development in El Salvador. We exploit the fact that the emergence of gangs in El Salvador was in part the consequence of an exogenous shift in US immigration policy that led to the deportation of gang leaders from the United States to El Salvador. Using the exogenous variation in the timing of the deportations and the boundaries of the territories controlled by the gangs, we perform a spatial regression discontinuity design and a difference-in-differences analysis to estimate the causal effect that living under the rule of gangs has on development outcomes. Our results show that individuals living under gang control have significantly worse education, wealth, and less income than individuals living only 50 meters away in areas not controlled by gangs. None of these discontinuities existed before the arrival of gangs from the US. The results are not determined by exposure to violence, lower provision of public goods, or selective migration away from gang locations. We argue that our findings are mostly driven by gangs restricting residents' mobility and labor choices. We find that individuals living under the rule of gangs have less freedom of movement and end up working in smaller firms. The results are relevant for many developing countries where non-state actors control parts of the country.
Keywords: Gangs, Development, Latin America, MS-13, Crime, Mobility