Flynn Effect... Louisville Twin Study (longitudinal data collected continuously from 1957 to 1999): Overall gains equaled approximately three IQ points per decade

Genetically informed, multilevel analysis of the Flynn Effect across four decades and three WISC versions. Evan J. Giangrande, Christopher R. Beam, Deborah Finkel, Deborah W. Davis, Eric Turkheimer. Child Development, November 11 2021. https://doi.org/10.1111/cdev.13675

Abstract: This study investigated the systematic rise in cognitive ability scores over generations, known as the Flynn Effect, across middle childhood and early adolescence (7–15 years; 291 monozygotic pairs, 298 dizygotic pairs; 89% White). Leveraging the unique structure of the Louisville Twin Study (longitudinal data collected continuously from 1957 to 1999 using the Wechsler Intelligence Scale for Children [WISC], WISC–R, and WISC–III ed.), multilevel analyses revealed between-subjects Flynn Effects—as both decrease in mean scores upon test re-standardization and increase in mean scores across cohorts—as well as within-child Flynn Effects on cognitive growth across age. Overall gains equaled approximately three IQ points per decade. Novel genetically informed analyses suggested that individual sensitivity to the Flynn Effect was moderated by an interplay of genetic and environmental factors.

Short-term mating was unrelated or even negatively related to reproductive success; long-term mating predicted a greater number of children and children's children

Phenotypic Signals of Sexual Selection and Fast Life History Dynamics for the Long-Term but Not Short-Term Mating. Janko Međedović. Evolutionary Psychology, November 29, 2021. https://doi.org/10.1177/14747049211057158

Abstract: Mating patterns are crucial for understanding selection regimes in current populations and highly implicative for sexual selection and life history theory. However, empirical data on the relations between mating and reproductive outcomes in contemporary humans are lacking. In the present research we examined the sexual selection on mating (with an emphasis on Bateman's third parameter – the association between mating and reproductive success) and life history dynamics of mating by examining the relations between mating patterns and a comprehensive set of variables which determine human reproductive ecology. We conducted two studies (Study 1: N = 398, Study 2: N = 996, the sample was representative for participants’ sex, age, region, and settlement size). The findings from these studies were mutually congruent and complementary. In general, the data suggested that short-term mating was unrelated or even negatively related to reproductive success. Conversely, long-term mating was positively associated with reproductive success (number of children in Study 1; number of children and grandchildren in Study 2) and there were indices that the beneficial role of long-term mating is more pronounced in males, which is in accordance with Bateman's third principle. Observed age of first reproduction mediated the link between long-term mating and number of children but only in male participants (Study 2). There were no clear indications of the position of the mating patterns in human life history trajectories; however, the obtained data suggested that long-term mating has some characteristics of fast life history dynamics. Findings are implicative for sexual selection and life history theory in humans.

Keywords: short-term mating, long-term mating, fitness, reproductive ecology, sexual selection, life history theory

General Discussion

Variation in mating behavior is certainly one of the crucial determinants of variance in fitness itself. Interestingly, the empirical data on the associations between mating and reproduction as a prerequisite for the analysis of selection regimes acting on mating, including sexual selection, are surprisingly lacking, especially in industrial and postindustrial human populations. This topic is of high importance, not only from the viewpoint of sexual selection, but life history theory in humans as well, together with the potential demographic implications. In order to explore the role of mating in reproductive ecology we conducted two studies with samples which differ in important reproductive characteristics (including the mean age of participants in two samples) and assessing different outcomes related to the environment and reproductive events. Despite the large differences between the samples the results were relatively congruent: 1) long-term mating turned out to be beneficial to fitness, while in contrast, short-term mating was either non-associated or even negatively associated to fitness; 2) long-term mating showed enhanced adaptive benefits for males compared to females; 3) age of first reproduction was the crucial mediating variable in the link between long-term mating and fitness in males; 4) short and long-term mating did not show unambiguous life history dynamics in the context of the fast/slow continuum; however, the obtained findings suggested that long-term mating had more consistent associations with the fast life history dynamics. The data show promising potential in understanding the reproductive ecology of mating in post-industrial humans as well as patterns of sexual selection in contemporary human populations.

Sexual Selection on Mating

Present findings revealed crucial differences in short and long-term mating regarding their relations with fitness: long-term mating showed more positive associations with fitness compared to short-term mating, where no relations or even negative relations with fitness were observed. In Study 1, long-term mating was positively associated with reproductive success and the total desired number of children; it was positively associated both with the number of children and grandchildren in Study 2. In both studies, longer partner relationships were related to an earlier age of first reproduction which turned out to be the crucial mediator between long-term mating and fitness for male participants. The findings that individuals with higher time spent in romantic relationships have higher fitness as well are in accordance not only with the previous findings obtained in post-industrial, WEIRD population (Međedović, 2021) but with the data obtained in rural, natural fertility population - Pimbwe tribe of West Tanzania (Borgerhoff Mulder & Ross, 2019). In contrast, short-term mating was related to delaying reproduction in Study 1 and a lower number of children in Study 2.

We examined Bateman's three coefficients (Arnold & Duvall, 1994; Bateman, 1948) in order to estimate the presence of sexual selection: variance in mating, reproduction, and the association between mating and reproduction. Of course, we should be cautious in the interpretation of variance in mating and fertility: reliable estimations of these parameters should involve representative samples. Our samples were not representative of the Serbian population, although the sample examined in Study 2 had several characteristics of representativeness. Having in mind the problems of results generalizability, it is interesting to mention that all of the effects detected were in congruence with the sexual selection theory: the variation in mating (observed in Study 1 and 2), reproductive success (Study 2) and the finding of higher associations between mating and reproduction in males compared to females (Study 1 and 2). These findings are in accordance with several previous empirical studies (Borgerhoff Mulder & Ross, 2019; Brown et al., 2009; Courtiol et al., 2012; Jokela et al., 2010), although none one of these studies were conducted in industrial and post-industrial human populations. This is particularly interesting since theory and previous data show that sexual selection is weaker in monogamous, compared to polygamous societies (Moorad et al., 2011). Hence, although probably with lower intensity, sexual selection still operates in contemporary humans; more precisely, selection primarily acts to enhance male effort in long-term mating.

Can Mating Patterns Indicate Life History Trajectories?

Apart from sexual selection, mating patterns could be a part of human life history dynamics: correlated traits and events which are associated with fitness. Due to differences in ecological conditions and individual characteristics, humans (like other species as well) may have different pathways of fitness maximization, which are often labeled as fast and slow (Del Giudice et al., 2015). However, there are two opposite hypotheses of the role that mating patterns play in life history dynamics: one assumes that short-term mating represents a part of fast life history trajectory (Belsky et al., 1991; Chisholm, 1999), while the other posits the same role for long-term mating (Gangestad & Simpson, 2000). Both hypotheses have acquired some empirical support but it seems that there are more findings which corroborate the former one (Chua et al., 2016; Copping & Campbell, 2015; Kogan et al., 2015; Lukaszewski, 2015; Schmitt, 2005). The present data did not provide findings which may unambiguously support either of these hypotheses. However, the present data was more in line with strategic pluralism theory (Gangestad & Simpson, 2000). Short term mating showed the signatures of both fast and slow life history while long-term mating exhibited more consistent fast life history dynamics. Indeed, the present data is in the accordance with recent predictions that long-term mating may indicate faster life history dynamics (Sear, 2020): having longer romantic relationships can facilitate reproductive success by higher frequency of sexual intercourse in steady relationships (Twenge et al., 2017) or avoiding the cost of switching partners on reproductive fitness (Brown et al., 2009).

Why were there no clearer associations between mating and life history? Well, the view of life history as a singular slow-fast dimension may be an oversimplifying framework for the analysis of human life histories. Recently, several critiques of the slow-fast life history continuum's existence have been published (Royauté et al., 2018; Stearns & Rodrigues, 2020; Zietsch & Sidari, 2020). Furthermore, empirical data showed that the latent space of life history indicators probably cannot be reduced to a single slow-fast dimension, i.e. it is much more complex and consists of several largely unrelated factors (Međedović, 2020a; 2020b; Richardson et al., 2021). The relations between the parameters of reproductive ecology and childhood environment obtained in the present study (i.e. low magnitude correlations with a high number of non-significant associations) are in contrast to the existence of a singular slow-fast continuum as well. Hence, it is questionable if this simple slow-fast life history theoretical framework is useful for understanding of the mating patterns’ role in life history dynamics. This is why it has been suggested that researchers should invest more effort in linking behavioral traits (like mating patterns) with the specific life history tradeoffs than trying to incorporate them in a rigid and oversimplifying fast-slow continuum (Sear, 2020).

Limitations and Future Directions

There are several important limitations of the present research. As we have already mentioned, the samples of participants the data were collected on were not representative, which limits the generalization of the data (although, the Study 2 was conducted on a large sample which was representative in several demographic parameters). The variation of the reproductive success in Study 1 was diminished which represents a potential obstacle to the generalization of the findings. Additional socio-demographic measures would be useful in the context of present topic - especially the estimate of participants’ income. Participants’ education levels were above the average in the present research; we can reasonably assume that the same holds for their income as well because education and economic status are positively correlated. Hence, the research findings cannot easily generalize to the participants with low education and socioeconomic status. The conducted studies were cross-sectional, which prevents causal inferences from the data; this is a limitation of previous studies in this topic as well. Despite the fact that early fertility is positively associated with completed fertility we should take the measure of reproductive success from Study 1 with caution. We did not use objective information about the participants’ childhood environment but the subjective estimations of ecological characteristics: future research may analyze objective indicators of environment like mortality rates, characteristics of the healthcare system or childhood environmental instability. Furthermore, parental fitness was not controlled for in the present research; future studies should not only control for parental reproductive success but examine the parental influence on mating in offspring, since there is a parent-offspring conflict regarding the mate choice (Buunk et al., 2008).

Incorporating a 12-step philosophy (and inserting religiosity without client’s consent) into therapy can make sexual compulsivity worse because of increasing shame and colluding with a power imbalance between therapist & client

The religious disguise in “sex addiction” therapy. Silva Neves. Sexual and Relationship Therapy, Nov 26 2021. https://doi.org/10.1080/14681994.2021.2008344

Abstract: In this essay I will discuss the conceptualisation of “sex addiction” programmes and treatments in relation to its religious positions. Both the official book of Sex Addicts Anonymous and “sex addiction” experts proclaim to offer a non-religious solution suitable for all people suffering from “sexual addiction” however a brief overview of some current texts reveals strong religiosity. In popular discourse, the USA is often perceived as more religious than the UK because of its puritan past. Whilst the UK is perceived to be more “sex positive,” I will demonstrate that religiosity amongst “sex addiction” experts in the UK is also strong, and perhaps more covert. This essay covers the problematic use of the integration of 12-step programmes in therapeutic treatments for sexual compulsivity. I will challenge the conceptualisation of “sex addiction,” primarily how experts promote support groups such as SAA and SLAA. The philosophy of these support groups is in direct contradiction with the knowledge of sexology and some basic psychotherapy principles. I argue that incorporating a 12-step philosophy (and inserting religiosity without client’s consent) into therapy can make sexual compulsivity worse because of increasing shame and colluding with a power imbalance between therapist and client. I propose that it is not possible to be both “sex positive” and promoting the conceptualisation of “sex addiction.”

Keywords: Compulsive sexual behaviourssexual compulsivitysex addiction12-step programmesaddictionreligiosity

Population ethical intuitions: Participants on average believed that approximately 1.5–3 times more happy people are required to outweigh a given amount of unhappy people

Population ethical intuitions. Lucius Caviola et al. Cognition, Volume 218, January 2022, 104941. https://doi.org/10.1016/j.cognition.2021.104941

Abstract: Is humanity's existence worthwhile? If so, where should the human species be headed in the future? In part, the answers to these questions require us to morally evaluate the (potential) human population in terms of its size and aggregate welfare. This assessment lies at the heart of population ethics. Our investigation across nine experiments (N = 5776) aimed to answer three questions about how people aggregate welfare across individuals: (1) Do they weigh happiness and suffering symmetrically?; (2) Do they focus more on the average or total welfare of a given population?; and (3) Do they account only for currently existing lives, or also lives that could yet exist? We found that, first, participants believed that more happy than unhappy people were needed in order for the whole population to be net positive (Studies 1a-c). Second, participants had a preference both for populations with greater total welfare and populations with greater average welfare (Study 3a-d). Their focus on average welfare even led them (remarkably) to judge it preferable to add new suffering people to an already miserable world, as long as this increased average welfare. But, when prompted to reflect, participants' preference for the population with the better total welfare became stronger. Third, participants did not consider the creation of new people as morally neutral. Instead, they viewed it as good to create new happy people and as bad to create new unhappy people (Studies 2a-b). Our findings have implications for moral psychology, philosophy and global priority setting.

Keywords: HappinessSufferingMoral judgmentPopulation ethicsAxiology

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[...] participants on average believed that approximately 1.5–3 times more happy people are required to outweigh a given amount of unhappy people.

In the Laterality Journal: Asymmetries of Brain, Behaviour, and Cognition... The effects of sex and handedness on masturbation laterality and other lateralized motor behaviours

The effects of sex and handedness on masturbation laterality and other lateralized motor behaviours. Paul Rodway, Volker Thoma &Astrid Schepman. Laterality, Nov 26 2021. https://doi.org/10.1080/1357650X.2021.2006211

Abstract: Masturbation is a common human behaviour. Compared to other unimanual behaviours it has unique properties, including increased sexual and emotional arousal, and privacy. Self-reported hand preference for masturbation was examined in 104 left-handed and 103 right-handed women, and 100 left-handed and 99 right-handed men. Handedness (modified Edinburgh Handedness Inventory, EHI), footedness, eyedness, and cheek kissing preferences were also measured. Seventy nine percent used their dominant hand (always/usually) for masturbation, but left-handers (71.5%) were less consistently lateralized to use their dominant hand than right-handers (86.5%). Hand preference for masturbation correlated more strongly with handedness (EHI), than with footedness, eyedness, or cheek preference. There was no difference in masturbation frequency between left- and right-handers, but men masturbated more frequently than women, and more women (75%) than men (33%) masturbated with sex aids. For kissing the preferred cheek of an emotionally close person from the viewer’s perspective, left-handers showed a left-cheek preference, and right-handers a weaker right-cheek preference. The results suggest that hemispheric asymmetries in emotion do not influence hand preference for masturbation but may promote a leftward shift in cheek kissing. In all, masturbation is lateralized in a similar way to other manual motor behaviours in left-handed and right-handed men and women.

Keywords: Vibratorhead-tiltstimulationgenitalshealth

Discussion

The findings clearly addressed the hypotheses outlined in the Introduction. The hypothesis (H1) that people would strongly prefer to use their dominant hand to masturbate was confirmed in the data, with 79% of people always/usually preferring their dominant hand. There was no evidence for the lay belief that men often masturbate with their non-dominant hand because it will feel “like someone else”. The hypothesis (H3) that left-handers would be less lateralized for hand use for masturbation was also confirmed, with 86.5% of right-handers preferring their dominant hand compared to 71.5% of left-handers. This result corresponded to the findings of other studies that had found weaker lateralization of unimanual motor behaviours in left-handers (McManus et al., 2016).

The hypothesis (H2) that handedness for masturbation might be a purer measure of handedness than the EHI, due to it being less influenced by social factors, was rejected, with the EHI proving to be a stronger measure of handedness. This shows that despite the private nature of masturbation (Kirschbaum & Peterson, 2018), there was no greater tendency to use the dominant hand for masturbation compared to other motor behaviours. In addition, the hypothesis (H4) that greater specialization of the RH for sexual arousal and emotion would cause a shift towards greater use of the left hand, in both right-handers and left-handers, did not receive support. Unlike other behaviours, such as kissing and cradling, where the emotional context influences lateralized motor behaviour (Ocklenburg et al., 2018), this appeared not to be the case for masturbation. This might be because cradling, kissing, and embracing are social behaviours, whereas masturbation is primarily a private behaviour.

Finally, the hypothesis (H5) that females would show greater use of their dominant hand for masturbation than men, particularly for manual masturbation, due to a greater need for fine motor control, was not supported. Males and females preferred using their dominant hand to a similar extent (77% males, 81% females). Interestingly, however, for the use of sex aids women were found to use their dominant hand more than males. A possible reason for this difference is that when using a sex aid, males may be more likely to manipulate their genitalia with their dominant hand, and hold the sex aid in their non-dominant hand to stimulate other regions.

In addition to showing a weaker hand preference for masturbation, left-handers were also less strongly lateralized than right-handers for footedness. This replicates observational findings (Nachshon & Denno, 1986) and strengthens the view that the data accurately reflect the participants’ behaviour. For eyedness the degree of lateralization did not differ significantly between left-handers and right-handers. This might be because eyedness is not as closely related to hand preference as is footedness (Nachshon & Denno, 1986), making the relationship between eyedness and handedness less consistent in both left- and right-handers.

For cheek kissing an interesting lateralization pattern emerged. Research studies have found that head tilting during kissing is influenced by handedness (Ocklenburg & Güntürkün 2009), and embracing is influenced by emotional context, with a leftward shift in emotional embraces (Packheiser et al., 2019). Both of these influences were observed in our data on cheek kissing. There was an overall bias for participants to kiss the left cheek (from the perspective of the kisser) of a person they were emotionally close to who was facing them. This effect was qualified by a significant effect of handedness, with left-handers showing a significant tendency to kiss the left cheek and the right-handers the right cheek, with the stronger tendency in the left-handers carrying the overall left-cheek bias. In addition, compared to the stronger rightward lateralization of handedness, footedness and masturbation, for cheek kissing there was an overall stronger leftward lateralization. This leftward bias in cheek kissing is consistent with the right hemisphere hypothesis of emotional asymmetries, with the greater involvement of the RH biasing motor behaviour towards the left (Ocklenburg et al., 2018). A further possibility is that it is related to a more general leftward bias when interacting with visual stimuli (Ciricugno et al., 2021; Jewell & McCourt, 2000; Nicholls & Roberts, 2002; Rodway & Schepman, 2020). Both interpretations require further research to determine the cause of this effect.

Chapelain et al. (2015) previously used a self-report measure of cheek kissing, similar to the one used in the present study. They measured choice of cheek and number of kisses for social greetings from various regions throughout France, and found an effect of region on cheek choice but no effect of handedness. The discrepant effects of handedness between Chapelain et al.’s research and the present study can be explained by the fact that cheek kissing for a social greeting, involving multiple kisses, is a very different interaction from a single kiss on the cheek of an emotionally close person. Importantly, the results from the present study replicate previous effects of handedness on lateralized kissing biases (Ocklenburg & Güntürkün 2009; Karim et al., 2017), with our study using a different task and a large sample of left-handers.

Other results were also in line with expectations and showed that the data calibrated well with previous research. Men were found to masturbate more than women, replicating previous findings (Leitenberg, et al., 1993; Driemeyer, et al., 2017) and a similar frequency of sex aid use by males for masturbation (33%) was found to that reported by Herbenick et al. (2017). The use of sex aids by women in our sample (75%) was somewhat higher (52.5%) than reported by Herbenick et al. (2009), and the 50.2% of vibrator or dildo use reported in Herbenick et al. (2017). This could be due to several factors, such as our participants self-selecting to opt into a study about masturbation, an increase in the use of sex aids over recent years, cultural differences between the US and the UK, and the fact that our data were collected during the coronavirus / Covid-19 pandemic.

In a survey of sexual behaviours of people in the United States, a substantial proportion of men (82.3%) and women (60.4%) reported having watched pornography (Herbenick et al., 2017). In the present study, participants were asked which hand they typically used to masturbate and which hand they typically used if they were not holding anything else. This was to check, for those participants who masturbated while viewing pornography (and which could involve the use of their dominant hand to control a computer mouse, or hold written material), if there was an increase in the use of the dominant hand when they were not holding anything else. However, we found no significant difference overall between these questions. Our data therefore suggested that preferred hand use for masturbation was not strongly determined by holding other objects and that participants continued to use their dominant hand for masturbation even when they might be holding something else. A possible limitation, however, is that we did not directly ask which hand they used when viewing pornography, and it is possible that if we had asked this question there might have been evidence of a shift towards using the non-dominant hand.

In the majority of left- and right-handers, eyedness and footedness was congruent with their handedness, replicating previous findings (Bourassa, McManus, & Bryden, 1996; Porac, 1997). In addition, hand preference for masturbation correlated more strongly with scores on the modified Edinburgh Handedness Inventory, than with footedness, eyedness, or kissing. Masturbation had a strength of hand preference (53 for typical hand) that fell between that shown via the modified EHI score (71), and both footedness (32) and eyedness (33), with significant differences between masturbation with the typical hand and modified EHI. This suggests that, although dominant hand preference for masturbation was weaker than that measured via the modified EHI, it may nevertheless be a reliable measure of hand preference in general. It can also be noted that historically in some cultures, such as India and ancient Rome, masturbation has been specifically linked with using the left hand (Derrett, 2006). Despite this historical association, there was no evidence in our sample of UK participants that such an association caused large numbers of right-handers to use their left hand.

An interesting incidental finding is that there were no differences in masturbation frequency between left- and right-handers for either men or women. Occasionally, research has tended to pathologise left-handedness (see Porac, 2015 for a discussion), rather than treating it as a natural variation that provides fitness benefits (Groothuis, et al., 2021), with an emphasis on health issues (Peters et al., 2006) and increases in atypical sexual behaviours (Fazio, Lykins, & Cantor, 2014). Also, some theories of the origin of left-handedness have linked it to increased levels of prenatal testosterone (see Grimshaw, Bryden, & Finegan, 1995; Richards et al., 2021, for discussions). As higher levels of testosterone in adults have been associated with more frequent masturbation (O’Connor, et al., 2011), theoretically, although via a speculative leap, it could be hypothesized there might be a difference in masturbation frequency between left- and right-handers. There was no evidence of this in the data, which is in line with the body of research showing that left- and right-handers are much more similar to each other than they are different (see Porac, 2015 for a review).

There are a number of potential limitations with the present study. The results might be specific to our UK sample and our exclusion criteria, which asked prospective participants whose culture or beliefs strongly determined which hand they used for certain actions not to take part. This was to elicit reports of natural, rather than culturally-conditioned behaviours. It may be that cultures that associate using the left hand with activities that may be classed as impure could show different patterns of behaviour, perhaps with a higher proportion of right-handers using their left hand for masturbation. The data were also based on self-report, rather than observation, for obvious ethical and moral reasons, raising the possibility they did not accurately represent participants’ behaviour. However, the results calibrate well with findings from other research, which gives confidence in their accuracy and validity. In addition, it is likely that the anonymity and privacy of the survey enabled participants to feel more able to respond honestly to the questions, than if the data had been collected in a less anonymous way, even if this had been ethically and morally acceptable. Thus, the constraints placed on the data acquisition method may not necessarily have been a hindrance in the collection of reliable data.

To summarize, hand preference for masturbation was strongly lateralized, with most people preferring to use their dominant hand, perhaps because it affords greater motor control, or because they use that hand for most activities. Right-handers were more strongly lateralized than left-handers for masturbation, EHI, and footedness, but left-handers more for kissing. There was no evidence for masturbation being more strongly lateralized than the behaviours measured by the Edinburgh Handedness Inventory. A small proportion of people chose to use their non-dominant hand for masturbation. This was not due to other objects occupying their dominant hand. There was no evidence that specialization of the RH for sexual arousal or emotion caused a shift towards greater use of the left hand for masturbation. However, there was a general leftward shift in cheek kissing. This finding is compatible with the RH hypothesis of emotional lateralization, with the greater involvement of the RH during the emotional behaviour of kissing, biasing motor behaviour towards the left. Therefore emotional context may influence lateralized motor behaviour particularly in social settings (such as kissing), rather than in a setting which can induce emotion but which is private (masturbation). In all, masturbation shows a similar pattern of lateralization to other unimanual behaviours in left-handed and right-handed men and women.

Formal religious practices statistically predicted increased severity of suicidal thoughts, while belief in God did not; religious conflict was also associated with increased severity of suicidal thoughts

Rabasco, A., & Andover, M. (2021). The relationship between religious practices and beliefs and suicidal thoughts and behaviors among transgender and gender diverse adults. Psychology of Religion and Spirituality, Nov 2021. https://doi.org/10.1037/rel0000453

Abstract: Transgender and gender diverse (TGD) people are at heightened risk for suicidal thoughts and behaviors (James et al., 2016). Some studies have found that religious practices and beliefs are positively associated with suicidal thoughts or behaviors among TGD individuals (Gibbs & Goldbach, 2015), while other studies have found a negative association (Grossman et al., 2016) or no relationship (Yüksel et al., 2017). In order to better understand the relationship between religion and suicidal thoughts and behaviors among TGD people, the present study investigated the relationship between religious practices, belief in God, and religious conflict, and suicidal thoughts and behaviors. TGD adults (N = 180) were recruited and completed questionnaires online assessing religious practices, religious conflict, and suicidal thoughts and behaviors. It was found that formal religious practices statistically predicted increased severity of suicidal thoughts, while belief in God did not. Religious conflict was also associated with increased severity of suicidal thoughts. Specifically, participants who reported currently holding religious beliefs that were not accepting of their gender identity had significantly higher severity of suicidal thoughts compared to participants who reported currently holding religious beliefs that were accepting of their gender identity. No relationship between religious practices and beliefs and suicidal behaviors emerged. These findings underscore the nuanced relationship between religion and suicidality among TGD people. They also point to the potential for religious communities to help reduce suicidal ideation among TGD members by fostering personal religious beliefs that are accepting of diverse gender identities.

Countries and Cultural Differences in the Stigma of Mental Illness: The East–West Divide

Countries and Cultural Differences in the Stigma of Mental Illness: The East–West Divide. Anne C. Krendl, Bernice A. Pescosolido. Journal of Cross-Cultural Psychology, February 21, 2020. https://doi.org/10.1177/0022022119901297

Abstract: Mental illness is a global public health crisis. Although rates of untreated cases stand as a primary problem, stigma is a significant obstacle. Yet, global differences in levels and roots of stigma remain poorly understood. Using the Stigma in Global Context–Mental Health Study (SGC-MHS) data, we analyzed data on two components of stigma—prejudice and discriminatory potential—attached to clinically diagnostic cases of depression and schizophrenia. We examined whether stigma was higher in the East than West. Furthermore, we hypothesized that the link between prejudice and discriminatory potential in the East was due, in part, to cultural differences in the attributions about mental illness. With SGC-MHS’ nationally representative vignette data from over 11,000 respondents in 11 relevant countries (four Eastern, seven Western), analyses replicated past research of higher levels of stigma and more moral attributions in Eastern countries, particularly for depression. Moreover, prejudice-related disclosure spillover concerns predicted discriminatory potential (social distance) in the East, but not the West; this was driven by a greater emphasis on moral attributions in the East. Finally, exploratory analyses found that Western respondents endorsed higher discrimination for minority (vs. majority) group members with mental illness. In Eastern countries, the same pattern emerged for schizophrenia, but the reverse occurred for depression—greater stigma for majority as compared with minority group members. Together, these findings suggest that cultural differences in the sources of prejudice and attributions about the etiology of mental illness contribute, at least in part, to global differences in the profile of stigma.

Keywords: mental health stigma, global, double jeopardy, depression, schizophrenia, mental illness

Paper suggests older humans are actually evolved to be much more physically active for longer than we usually are, & that physical activity is therefore extremely protective against chronic disease and extends life & health

The active grandparent hypothesis: Physical activity and the evolution of extended human healthspans and lifespans. Daniel E. Lieberman et al. Proceedings of the National Academy of Sciences, December 14, 2021 118 (50) e2107621118; https://doi.org/10.1073/pnas.2107621118

Abstract; The proximate mechanisms by which physical activity (PA) slows senescence and decreases morbidity and mortality have been extensively documented. However, we lack an ultimate, evolutionary explanation for why lifelong PA, particularly during middle and older age, promotes health. As the growing worldwide epidemic of physical inactivity accelerates the prevalence of noncommunicable diseases among aging populations, integrating evolutionary and biomedical perspectives can foster new insights into how and why lifelong PA helps preserve health and extend lifespans. Building on previous life-history research, we assess the evidence that humans were selected not just to live several decades after they cease reproducing but also to be moderately physically active during those postreproductive years. We next review the longstanding hypothesis that PA promotes health by allocating energy away from potentially harmful overinvestments in fat storage and reproductive tissues and propose the novel hypothesis that PA also stimulates energy allocation toward repair and maintenance processes. We hypothesize that selection in humans for lifelong PA, including during postreproductive years to provision offspring, promoted selection for both energy allocation pathways which synergistically slow senescence and reduce vulnerability to many forms of chronic diseases. As a result, extended human healthspans and lifespans are both a cause and an effect of habitual PA, helping explain why lack of lifelong PA in humans can increase disease risk and reduce longevity.

Keywords: physical activityexerciselifespanhealthspanevolution

594,196 fifteen-year-olds, 77 countries: girls experience less physical & verbal victimization & have stronger anti-bullying attitudes; physical victims have less –not more--anti-bullying attitudes

Marsh, Herb, Jiesi Guo, Philip D. Parker, Reinhard Pekrun, Geetanjali Basarkod, Theresa Dicke, Roberto H. Parada, et al. 2021. “An Integrative Review of Cross-national Comparisons of Verbal, Relational, and Physical Peer Victimization: Gender Differences, Paradoxical Anti-bullying Attitudes, and Well-being.” PsyArXiv. November 23. doi:10.31234/osf.io/qfmek

Abstract: Current victimization studies and meta-analyses are based mainly on a unidimensional perspective in a few developed OECD countries. This provides a weak basis for generalizability over multiple victimization (relational, verbal, physical) components and different countries. We test the cross-national generalizability (594,196 fifteen-year-olds; 77 countries) of competing victimization models. In support of our three-component model, differentiating the multiple components of victimization facilitated understanding: gender differences (girls experience less physical and verbal victimization and stronger anti-bullying attitudes, but relational differences are small); paradoxical anti-bullying attitudes (physical victims have less –not more--anti-bullying attitudes); and well-being (policy/practice focuses primarily on physical victimization, but verbal and relational victimization effects are larger). These key findings provide theoretical advances with implications for policy, practice, and intervention.

Smell loss was quantified as the single best predictor of COVID19; this specificity was used to create a novel tool, the ODoR-19 (Olfactory Determination Rating Scale in COVID-19) scale, for use in rapid screening

Massively collaborative crowdsourced research on COVID19 and the chemical senses: insights and outcomes. Elisabeth M. Weir et al. Food Quality and Preference, November 26 2021, 104483. https://doi.org/10.1016/j.foodqual.2021.104483

Highlights

• The Global Consortium of Chemosensory Research (GCCR) was founded in Spring 2020.

• Results from GCCR research on COVID19 and the chemical senses are summarized.

• Some open science approaches used by the GCCR are highlighted.

Abstract: In March 2020, the Global Consortium of Chemosensory Research (GCCR) was founded by chemosensory researchers to address then emerging reports of unusual smell and taste dysfunction arising from the SARS-CoV-2 pandemic. Over the next year, the GCCR used a highly collaborative model, along with contemporary Open Science practices, to produce multiple high impact publications on chemosensation and COVID19. This invited manuscript describes the founding of the GCCR, the tools and approaches it used, and a summary of findings to date. These findings are contextualized within a summary of some of the broader insights about chemosensation (smell, taste, and chemesthesis) and COVID19 gained over the last 18 months, including potential mechanisms of loss. Also, it includes a detailed discussion of some current Open Science approaches and practices used by the GCCR to increase transparency, rigor, and reproducibility.

Keywords: GCCRCOVID19anosmiatasteopen sciencesmell

3. Summary of some initial findings from the GCCR

While all the GCCR papers to date have resulted in key insights on COVID-19 and its effects on all three chemosesenses, the first GCCR paper (Parma et al., 2020) provided especially vital information. This analysis asked a simple question: “did self-assessment of taste, smell, and chemesthesis during illness differ from retrospective assessment of chemosensory function prior to illness?” This was determined by asking participants to rate their smell ability on a 0-100 visual analog scale (VAS) during their illness, as well as retrospectively rating their smell ability prior to their illness on the same scale – the difference between these two self-reported ratings was taken as a measure of lost function. Parallel questions were asked for taste and oral chemesthesis. Using data from ∼4000 participants collected in 10 languages, Parma et al. found that a majority of COVID19 positive participants reported a significant drop in ability to smell, with a mean drop of almost 80 points relative to their ability to smell prior to their illness. This suggested anosmia was a characteristic symptom of COVID19 (Parma et al., 2020), confirming the anecdotal reports noted above. Taste and oral chemesthesis were also significantly blunted in individuals with COVID19, with mean decreases of ∼70 and ∼37 points, respectively (Parma et al., 2020). Notably, impairment of chemesthesis was typically accompanied by either taste and/or smell loss, although in other participants, taste and smell loss appeared when normal chemesthesis was preserved. Because the survey was based on self-report of function, rather than assessment with controlled stimuli, reports of taste loss may not actually reflect taste loss (which is very rare with other viral illnesses), but may instead reflect a common taste/smell confusion among the general public (and some clinicians; see (Boltong, Keast, & Aranda, 2011)). However, the survey also asked about alteration of specific taste qualities (i.e., salty, sweet, sour, bitter, and umami/savory) with check-all-that-apply (CATA) question, and significant deficits were also observed. Changes in specific taste qualities were consistently reported by ∼37 to 45% of participants for sweet, sour, salty and bitter; reports were slightly lower for umami/savory (∼25%) but this may reflect lack of familiarity with the concept of umami and/or translation difficulty, rather than any specific robustness of this quality against loss. As noted by Green (Green, 2020), a high endorsement of altered function was reported for salty (∼45%), a quality that is not commonly attributed to odors (in contrast to sweetness or sourness). Collectively, this suggested that reported taste loss is not merely an artifact arising from a taste/smell confusion, an observation that was subsequently confirmed by multiple studies that assess taste function using various stimuli, rather than relying on self-report. Although the quality of these studies is highly variable on balance, they support the view that some of taste loss reported by those with COVID19 reflects true disruption of the taste system.

Aligning with self-reports, over a dozen studies using various stimuli (e.g., strips, homemade solutions) indicate taste loss occurs with COVID19. Although the measures of taste in these studies were often ad hoc (given the urgency of the pandemic), it is still evident that true taste loss (and not merely a semantic taste-flavor confusion) is a characteristic feature of COVID-19. That is, validated methods, like those developed as part of the NIH Toolbox (Coldwell et al., 2013) or used for the National Health and Nutrition Examination Survey (NHANES) Chemosensory Exam (Rawal, Hoffman, Honda, Huedo-Medina, & Duffy, 2015), have not been employed to date. This is wholly understandable given the needs of clinicians and researchers to collect data as quickly as possible during early days of the pandemic, often when few resources were available. Moving forward, a prime goal of chemosensory scientists should be to apply rigorous test methods to study COVID-19 taste loss, especially in those with post-acute sequelae of COVID-19 (PASC). Still, the primary message here is that the preponderance of evidence, even with imperfect measures, indicates taste loss is a verifiable symptom of COVID-19.

COVID19 associated anosmia also appears to be distinct from the transient anosmia experienced with respiratory illnesses such as the common cold. With the common cold, smell loss typically co-occurs with a lack of airflow, as a consequence of nasal congestion – that is, volatile odor active molecules cannot reach receptors on the olfactory epithelium at the top of the nasal cavity, as mucus and/or swelling block the nasal passages. In the first GCCR survey, participants were also asked to report apparent congestion, via a rating of perceived nasal blockage, where a higher score indicated more blockage. The mean pre-COVID19 nasal blockage was almost zero, whereas the mean reported blockage during COVID19 was ∼22 points higher, suggesting some participants experienced some blockage. However, comparison of the distribution of nasal obstruction ratings before and after COVID19 indicated that many participants had little to no blockage during COVID19 (Parma et al., 2020), and more critically, principal components analysis (PCA) indicated ratings of blockage were independent to ratings of smell and taste loss. This implies acute change in olfactory function for COVID19 positive individuals was not attributable to simple conductive losses. Although mechanisms for changes in taste, smell, and chemesthesis remain to be elucidated, these early data suggested disruption of chemosensory function was a hallmark indicator of COVID19 infection.

After reporting that smell and taste loss were cardinal symptoms of COVID19, the GCCR analyzed a second data tranche from the same survey that included ∼15,000 responses in 23 languages collected between 7 April 2020 and 2 July 2020. Besides fully replicating findings from the first study among non-overlapping participants (n=4,825), the new report compared responses in COVID19 positive and negative individuals, all with recent respiratory symptoms (Gerkin et al., 2021). The primary goal was to try to predict COVID19 diagnosis from all reported symptoms, regardless of whether they were chemosensory in nature.

Using both categorical and binary responses, chemosensory symptoms were found to be more strongly associated with COVID-19 diagnosis than fever, cough, or any other non-chemosensory symptoms, including difficulty breathing. In fact, self-reported smell ability during illness was the single most predictive factor for COVID-19, followed by self-reported taste ability during illness. These results highlight the importance of chemosensory changes during COVID19 infection. As anticipated, smell, taste, and chemesthesis were reported to be greatly reduced for COVID19 positive individuals compared to COVID19 negative individuals. Also, this analysis confirmed that nasal obstruction was not predictive of COVID19. Overall, non-chemosensory symptoms were less specific symptoms than smell loss, allowing those with COVID19 to be distinguished from other respiratory illnesses. In summary, smell loss was quantified as the single best predictor of COVID19, and this specificity was used to create a novel tool, the ODoR-19 (Olfactory Determination Rating Scale in COVID-19) scale, for use in rapid screening (Gerkin et al., 2021).

Interoceptive accuracy, the ability to correctly perceive internal signals arising from the body: Men are better with heart signals; both sexes fail w/gastric or respiratory signals

Sex differences in interoceptive accuracy: A meta-analysis. Freya Prentice, Jennifer Murphy. Neuroscience & Biobehavioral Reviews, November 25 2021. https://doi.org/10.1016/j.neubiorev.2021.11.030

Highlights

• Sex differences in interoceptive accuracy are reported, but results are mixed.

• This meta-analysis sought to confirm the presence or absence of sex differences.

• Poor cardiac accuracy on counting and discrimination tasks was observed in females.

• Effects were less stable for non-cardiac due to varied methods and sample sizes.

• Results were mixed for respiratory, and no differences were observed for gastric.

Abstract: Interoceptive accuracy, the ability to correctly perceive internal signals arising from the body, is thought to be disrupted in numerous mental and physical health conditions. Whilst evidence suggests poorer interoceptive accuracy in females compared to males, raising the possibility that interoceptive differences may relate to sex differences in mental and physical health, results concerning sex differences in interoceptive accuracy are mixed. Given such ambiguity, this meta-analysis aimed to establish the presence or absence of sex differences in interoceptive accuracy across cardiac, respiratory, and gastric domains. A review of 7956 abstracts resulted in 93 eligible studies. Results demonstrated superior accuracy in males across cardiac, but not gastric, tasks, while findings on respiratory tasks were mixed. Effect sizes were consistent across cardiac tasks, but instability and/or moderate heterogeneity was observed across other domains, likely due to the small number of eligible studies. Despite such limitations, results indicate the possibility of sex differences across interoception tasks and domains. Methodological limitations concerning the influence of physiological factors, and directions for future research are discussed.

Keywords: interoceptive accuracycardiac interoceptionrespiratory interoceptiongastric interoceptionsex differencesmeta-analysis

In contrast to psychophysiological reactions, self-reported emotional reactions to threatening stimuli are reliably associated with ideology

The Psychophysiology of Political Ideology: Replications, Reanalyses, and Recommendations. Mathias Osmundsen, David J. Hendry, Lasse Laustsen, Kevin B. Smith, and Michael Bang Petersen. The Journal of Politics, Nov 2021. https://www.journals.uchicago.edu/doi/10.1086/714780

Abstract: This article presents a large-scale, empirical evaluation of the psychophysiological correlates of political ideology and, in particular, the claim that conservatives react with higher levels of electrodermal activity to threatening stimuli than liberals. We (1) conduct two large replications of this claim, using locally representative samples of Danes and Americans; (2) reanalyze all published studies and evaluate their reliability and validity; and (3) test several features to enhance the validity of psychophysiological measures and offer a number of recommendations. Overall, we find little empirical support for the claim. This is caused by significant reliability and validity problems related to measuring threat sensitivity using electrodermal activity. When assessed reliably, electrodermal activity in the replications and published studies captures individual differences in the physiological changes associated with attention shifts, which are unrelated to ideology. In contrast to psychophysiological reactions, self-reported emotional reactions to threatening stimuli are reliably associated with ideology.

Children’s gender accurately identified from their speech: Since young boys & girls overlap almost entirely in gross acoustic cues that drive gender perception for adults, results suggest accuracy based on transmission of more subtle gender information

Perception of gender in children's voices. Santiago Barreda and Peter F. Assmann. The Journal of the Acoustical Society of America 150, 3949 (2021), Nov 23 2021. https://doi.org/10.1121/10.0006785

Abstract: To investigate the perception of gender from children's voices, adult listeners were presented with /hVd/ syllables, in isolation and in sentence context, produced by children between 5 and 18 years. Half the listeners were informed of the age of the talker during trials, while the other half were not. Correct gender identifications increased with talker age; however, performance was above chance even for age groups where the cues most often associated with gender differentiation (i.e., average fundamental frequency and formant frequencies) were not consistently different between boys and girls. The results of acoustic models suggest that cues were used in an age-dependent manner, whether listeners were explicitly told the age of the talker or not. Overall, results are consistent with the hypothesis that talker age and gender are estimated jointly in the process of speech perception. Furthermore, results show that the gender of individual talkers can be identified accurately well before reliable anatomical differences arise in the vocal tracts of females and males. In general, results support the notion that the transmission of gender information from voice depends substantially on gender-dependent patterns of articulation, rather than following deterministically from anatomical differences between male and female talkers.

Narcissistic Individuals Exhibit Poor Recognition Memory; narcissistic individuals’ excessive self-focus predicted this memory deficit

Narcissistic Individuals Exhibit Poor Recognition Memory. Miranda Giacomin, Christopher Brinton, Nicholas O. Rule. Journal of Personality, November 19 2021. https://doi.org/10.1111/jopy.12690

Abstract: Here, we examine face memory among individuals who are self-focused and care little about others’ needs: grandiose narcissists. Given narcissistic individuals’ excessive self-focus and tendency to disregard the needs of others, they may struggle to recognize faces and their surrounding environment. Indeed, narcissistic individuals demonstrated worse recognition memory than non-narcissistic individuals in recognition memory tests for faces (Studies 1 [N = 332] and 2 [N = 261]). This difference also occurred for nonsocial stimuli (i.e., objects, houses, cars), suggesting a broad recognition deficit (Study 3A [N = 178], 3B [N = 203], 3C [N = 274]). Narcissistic individuals’ excessive self-focus predicted this memory deficit (Study 4 [N = 187]). Grandiose narcissism may therefore influence visual recognition memory, highlighting the potential for future research linking personality and cognitive performance.

Perceptions of early news coverage about COVID-19: Citizens had positive attitudes toward their own Covid-19 news sources, but were critical about the news sources others were using to get information about the virus

My pandemic news is better than yours: audience perceptions of early news coverage about Covid-19. Mallory R. Perryman. Communication Research Reports, Nov 23 2021. https://doi.org/10.1080/08824096.2021.2007070

Abstract: This study focuses on how American audiences perceived news coverage during the early days of the Covid-19 pandemic in the United States. Through a survey-experiment of news consumers (N = 767) over a three-day period in mid-March 2020, this study shows that citizens had positive attitudes toward their own Covid-19 news sources, but were critical about the news sources others were using to get information about the virus. Data reveal evidence of presumed media influence, where audiences believed others’ health behaviors were being influenced by pandemic news.

Keywords: Presumed media influencemedia perceptionsperceived news habitsthird-person effectfirst-person effectpresumed behavior

Umbrella review: Most adolescents experienced no or negligible effects of social media use on mental health

Social media use and its impact on adolescent mental health: An umbrella review of the evidence. Patti M. Valkenburg, Adrian Meier, Ine Beyens. Current Opinion in Psychology, Volume 44, April 2022, Pages 58-68. https://doi.org/10.1016/j.copsyc.2021.08.017

Abstract: Literature reviews on how social media use affects adolescent mental health have accumulated at an unprecedented rate of late. Yet, a higher-level integration of the evidence is still lacking. We fill this gap with an up-to-date umbrella review, a review of reviews published between 2019 and mid-2021. Our search yielded 25 reviews: seven meta-analyses, nine systematic, and nine narrative reviews. Results showed that most reviews interpreted the associations between social media use and mental health as ‘weak’ or ‘inconsistent,’ whereas a few qualified the same associations as ‘substantial’ and ‘deleterious.’ We summarize the gaps identified in the reviews, provide an explanation for their diverging interpretations, and suggest several avenues for future research.

Keywords: Meta-reviewSocial networking sitesSNSFacebookInstagramWell-beingDepressionDepressive symptoms

Discussion

In this umbrella review, we synthesized the results of 25 recent reviews into the effects of SMU on adolescent mental health. Given that adolescents’ SMU is continually changing, it is important to provide regular research updates on this use and its potential effects. In addition to the many important future directions raised in earlier reviews, we discuss three crucial avenues for future research.

Defining SMU, defining mental health

First, future research needs to consistently define the predictors and outcomes under investigation. Several reviews regularly switched between terms such as digital media use, technology use, and SMU without specifying to which media activities these terms refer. In some studies, emailing and gaming were part of the definitions of SMU, whereas others covered only time spent on SNSs. Such imprecise definitions may greatly hinder our understanding of the effects of SMU on mental health because different types of SMU may lead to different effects on mental health outcomes. For example, time spent on SNS is associated with higher levels of depression [17], whereas emotional connectedness to SNS (‘intensity of use’) [15] and the number of friends on SNS [16] are unrelated to depression. In the world of SM, everything is rapidly new and rapidly old, and, therefore, it is all the more important to define the specific types of SMU under investigation and to hypothesize how and why these types of SMU could affect mental health outcomes.

Likewise, in several reviews, both mental health and well-being were used as catchall terms that were left undefined, which sometimes led to the discussion of a potpourri of cognitive and affective outcomes that each deserve to be investigated in their own right. Our umbrella review confirmed that similar types of SMU can lead to opposite associations with different mental health outcomes [17]. Both SMU and mental health are highly complex constructs. Although most studies have focused on the associations of SMU with depression or depressive symptoms, all other constituent mental health outcomes, including their risk (e.g. loneliness) and resilience factors (e.g. self-esteem), also deserve our full research attention, provided that they are clearly defined and demarcated from other mental health outcomes.

Capturing the content and quality of SM interactions

Several reviews have pointed at a need to move away from possibly biased self-report measures toward more objective measures of SMU use, such as log-based measures of time spent with SM. Indeed, self-report measures of time spent with SM correlate only moderately with similar log-based measures [42,43]. However, although log-based measures are often seen as the gold standard, they have their own validity threats, such as technical errors and the erroneous tracing of SM apps running in the background when the screen is turned off [42,43]. This means that the modest correlations between self-reports and log-based measures could be due to validity issues of self-reports but also of objective measures. More importantly, though, most log-based measures only capture time spent with SM apps, which is just as crude a predictor of mental health as comparable self-report measures. If logging measures only reiterate the ‘screen time’ approach of most self-report research, they provide only a limited way forward.

To arrive at a true understanding of the effects of SMU on mental health, future research needs to adopt measures that capture adolescents' responses to specific content or qualities of SM interactions. In experimental settings, this can be realized by using mock SM sites, such as the Truman Platform (https://socialmedialab.cornell.edu/) or the mock SM site developed by Shaw et al. [44]. In non-experimental settings, there are three approaches that can be combined with survey or experience sampling studies: (1) The ‘Screenomics’ approach developed by Reese et al. [45], which entails end-to-end software that randomly collects screenshots of adolescents’ smartphones, and extracts text and images; (2) phone-based mobile sensing [46], which captures sound via the microphone and text entered via the keyboard; and (3) analysis of SM ‘data download packages’ [47], the archives of SM interactions that each SM user is allowed to download. While each of these methods is promising, they require sophisticated technical skills and specific expertise. Therefore, they can best be achieved in collaborative interdisciplinary projects, which are also better equipped to realize larger samples.

Understanding inconsistent interpretations

Although the majority of the reviews concluded that the reported associations of SMU with mental health were small to moderate, some others interpreted these associations as serious [30], substantial [48] or detrimental [25]. Such disagreeing interpretations can also be witnessed in three recent publications on SMU and mental health by Twenge et al. [49], Orben and Przybylski [3], and Kreski et al. [50], all relying on the same UK-based data set. Such divides in interpretations of the same modest effect sizes are certainly not new in the media effects field. For example, as of the 1980s, there has been a fierce debate among scholars about the effects of game violence on aggression (e.g. see the dispute in Psychological Bulletin about whether this effect is trivial or meaningful [51,52]). Oftentimes, the involved scholars do not disagree that much about the size of the reported effects but just on how to interpret them.

What has often been ignored in such debates is that the effect sizes are just what they are: statistics observed at the aggregate level. Such statistics are typically derived from heterogeneous samples of adolescents who may differ greatly in their susceptibilities to the effects of environmental influences in general [53] and media influences in particular [54]. After all, each adolescent is subject to unique dispositional, social-context, and situational factors that guide their SMU and moderate its effects [55]. Such person-specific antecedents and effects of SMU cannot be captured by the aggregate-level statistics that have been reported in the majority of empirical studies and reviews, including the current one.

If we accept the propositions of media-specific susceptibility theories [54], it is plausible to assume that both optimistic and pessimistic conclusions about the effects of SMU are valid — they just refer to different adolescents. In fact, recent studies that have adopted an idiographic (i.e. N = 1 or person-specific) media effects paradigm [56] have found that a small group of adolescents experienced negative effects of SMU on well-being (around 10–15%) and another small group experienced positive effects (also around 10%–15%). Reassuringly though, most adolescents experienced no or negligible effects [57].

A person-specific approach to media effects requires a large number of respondents and a large number of within-person observations per respondent. Indeed, statistical power is expensive. However, due to rapidly advancing technological (e.g. phone-based experience sampling methods) and methodological developments (e.g. N = 1 time series analyses), such approaches are increasingly within everyone's reach, especially when researchers pool resources in interdisciplinary teams. A person-specific media effects paradigm may not only help academics resolve controversies between optimistic and pessimistic interpretations of aggregate-level effect sizes, but it may also help us understand when, why, and for whom SMU can lead to positive or negative effects on mental health. And above all, it may help us facilitate personalized prevention and intervention strategies to help adolescents maintain or improve their mental health.