We provide evidence that pet dogs distinguish between human true beliefs & false beliefs scenarios, suggesting that the mechanisms underlying sensitivity to others' beliefs have not evolved uniquely in the primate lineage

Dogs follow human misleading suggestions more often when the informant has a false belief. Lucrezia Lonardo, Christoph J. Völter, Claus Lamm and Ludwig Huber. Proceedings of the Royal Society B: Biological Sciences, July 21 2021. https://doi.org/10.1098/rspb.2021.0906

Abstract: We investigated whether dogs (Canis familiaris) distinguish between human true (TB) and false beliefs (FB). In three experiments with a pre-registered change of location task, dogs (n = 260) could retrieve food from one of two opaque buckets after witnessing a misleading suggestion by a human informant (the ‘communicator’) who held either a TB or a FB about the location of food. Dogs in both the TB and FB group witnessed the initial hiding of food, its subsequent displacement by a second experimenter, and finally, the misleading suggestion to the empty bucket by the communicator. On average, dogs chose the suggested container significantly more often in the FB group than in the TB group and hence were sensitive to the experimental manipulation. Terriers were the only group of breeds that behaved like human infants and apes tested in previous studies with a similar paradigm, by following the communicator's suggestion more often in the TB than in the FB group. We discuss the results in terms of processing of goals and beliefs. Overall, we provide evidence that pet dogs distinguish between TB and FB scenarios, suggesting that the mechanisms underlying sensitivity to others' beliefs have not evolved uniquely in the primate lineage.

4. Discussion

This study aimed at investigating whether dogs would spontaneously behave in a different way in response to a misleading suggestion from a human informant with a TB or a FB and this is indeed what we found in experiment 1. The combined results of experiments 1 and 2 suggest that retroactive interference is not a likely explanation for the behaviour of dogs in this task. Finally, the results of experiment 3 show that performance in this task is subject to breed (group) differences.

Both conditions of experiment 1 (TB and FB) were characterized by very similar behavioural cues: the hider always moved food from container A to container B; the communicator always left and re-entered the room after the same amount of time, and afterwards always suggested the empty container A. Hence, the only difference between the TB and FB condition in experiment 1 was the moment in which the communicator re-entered the room: before (TB) or after (FB) the food displacement by the hider. From this difference, it could be inferred whether the communicator could or could not see the displacement of food and hence whether she was left with a FB (that food was still in bucket A), or whether her belief (that food was in bucket B) was updated and veridical.

In the absence of any previous training, dogs in the two groups of experiment 1 (TB, FB) behaved differently in response to the same misleading suggestion. More dogs in the FB than in the TB group approached and touched the suggested (empty) container. Given that the two scenarios differed in the timing of the communicator re-entering the room, we introduced a third condition to rule out the possible influence of the moment of re-entry. Indeed, one could have argued that dogs in the FB group of experiment 1 might have been distracted by the salient event of the communicator re-entering the room after the final hiding of food and hence were more inclined to trust the human signal due to retroactive interference (as already proposed for FB studies with human infants and adults [20,49]).

The events in the CTB condition had the potential to elicit the same retroactive interference (if not more) as those in the FB scenario. Indeed, dogs in the CTB witnessed the communicator both leaving and re-entering the room after the final hiding of food. The combined results of experiments 1 and 2, however, show that dogs in the two true belief scenarios reacted in the same way despite the difference in the order of the events. Therefore, dogs' responses did not depend on subtle details of the sequence of events in the experimental procedure. In line with findings that dogs showed an ability to judge human informants on the basis of what these have seen or not [40], our findings thus add further evidence that dogs possess the ability to differentiate between human knowledge states.

Prior to running the experiments, we had predicted that more dogs from the true belief group should have followed the communicator's cue. Surprisingly, instead, more dogs followed the communicator's misleading suggestion when the latter was absent during the food displacement (FB group). Thus, their behaviour was opposite to that of Buttelmann et al.'s human infants and apes [17,41], and to our own pre-registered hypothesis. A possible explanation for this behavioural pattern might reside in the way the communicator's intention was interpreted. In our experiment, the communicator first (during the familiarization trials) proved to be a reliable helper for the dogs and then during the test suggested for the first time the wrong container. In Buttelmann et al.'s studies [17,41], the participants were the ones asked to help the experimenter retrieve a hidden object, which was of no value for the participants themselves. In this kind of helping paradigm, the experimenter's goal was not to communicate to participants the location of the hidden object, therefore it is unlikely that participants viewed the experimenter as untrustworthy. In our task, however, it is possible that dogs in the true belief group interpreted the communicator's misleading behaviour as deceitful, or driven by another (unknown) intention, and therefore more dogs in this group (TB) than in the FB group ignored her suggestion and chose bucket B.

Previous studies have shown that dogs do not follow human misleading pointing gestures blindly (although sometimes they find them difficult to ignore [50]); instead, they can adjust their behaviour flexibly depending on the trustworthiness of the informant [51] and can discriminate between helpful and uncooperative experimenters [52]. Along this line of argument, it seems plausible to assume that dogs in both groups remembered the final location of food (bucket B). However, the communicator's misleading suggestion in the TB scenario might have appeared as deceitful if dogs attributed a true belief to the communicator. Whereas the same misleading suggestion (of bucket A) might have appeared as a mistake ‘in good will’ in the FB scenario if dogs understood that the communicator lacked the relevant knowledge (ignorance) or that she believed food was actually in container A (FB). This might explain why more dogs in the FB than in the TB group followed the misleading suggestion. Indeed, previous research indicates that dogs readily conform to a familiar and unfamiliar human's influence in object-choice tasks even when there is no apparent need to do so and, crucially, even when conforming leads to a suboptimal outcome for the dog [45,53–57]. In particular, Prato-Previde et al. [53] found that younger dogs were more easily misled by a human's influence than older ones, similar to the age effect revealed when pooling experiments 1 and 2 in the current study. We decided to test dogs from five months of age because Barnard et al. [55] had shown that the tendency to conform to human misleading suggestions is present in puppies already at 4 months. Similarly to what happened in our setting, Topál et al. [44] found that dogs in a hiding-finding game kept searching for a toy in previous hiding locations they knew to be empty. The authors suggest that such a ‘rule-following’ behaviour might minimize social conflicts and enhance social cohesion with humans [26,58]. In our task, the communicator with a FB might have been perceived as a mistaken informant who was still playing the game by the same rules as in the familiarization. Instead, the communicator with a true belief (suddenly switching to uncooperativeness) might have been perceived as less trustworthy or violating the rules of the game and this might explain why her suggestion was ignored more often.

Although we did not predict nor pre-register substantial breed effects, we had decided to test only pure-bred dogs in order to be able to explore possible differences. This resulted in the finding that the behaviour of terriers deviated from the one of most other breed groups (electronic supplementary material, figure S2 and S6). In particular, already in experiment 1, we observed a difference in the choice pattern of terriers (FCI group 3), on the one hand, and other breed groups, such as FCI group 2 (in our sample, Schnauzers, Molossoids and Swiss Mountain and Cattledogs), FCI group 7 (pointing dogs) and FCI group 8 (in our sample, retrievers) on the other hand. Unlike other breeds, more terriers from the TB group than from the FB group chose the empty container.

To confirm this unpredicted result, we tested new cohorts of terriers and border collies in experiment 3. We replicated our initial findings: while border collies behaved in accordance with the majority of breeds in experiment 1 (although we did not find a statistically significant difference between conditions; for comparison, the performance of the border collies in experiment 1 is shown in electronic supplementary material, figure S2) terriers exhibited the opposite behavioural pattern. The response pattern of the latter FCI group matches our initial prediction and is consistent with human infants' and great apes’ performance in a similar task [17,41].

We can only speculate about the reasons for the observed differences between FCI groups. The breed differences that have been reported in a scientific context mainly concern specific temperament traits [59,60], behaviours [61–63] and interspecific communicative abilities (e.g. tendency to look at a human's face and to follow pointing gestures [64–66]). Based on the working history of some breeds, Gácsi et al. [64] classified dogs into two main categories: cooperative and independent workers. Accordingly, dogs in the first category have been selected for cooperating while keeping continuous visual contact with their human partner, whereas the latter have been selected for working without any human visual contact. The authors found that cooperative workers (e.g. shepherds and gundogs) were more willing than independent ones (e.g. terriers, hounds, greyhounds and sledge dogs) to follow human distal, temporary pointing gestures. However, only limited attention has been devoted to the empirical investigation of dog breed differences in cognition [67]. An interesting exception is the study by Heberlein et al. [68], who found that independent workers and family dogs, when forbidden to eat food, were more skilled at taking their owner's perspective than cooperative workers. Based on the results of experiment 1, we decided to compare dogs considered as cooperative workers (here: border collies) to independent workers (here: terriers) in experiment 3. Terriers were chosen because they had shown the initially hypothesized response pattern in experiment 1; border collies because they have been extensively tested in studies on social cognition in our and other laboratories [69–71].

In the current study, breed differences might be indicative of different interpretations of the intentions behind human communicative signals. Indeed, terriers were not only more independent of the communicators' signal irrespective of condition, but they also reacted in the opposite way to the scenarios compared to pointing dogs, retrievers, molossoids and border collies (electronic supplementary material, figure S2 and S6). In particular, it is possible that many of the ‘cooperative workers’ in our study interpreted the communicators' cue in the TB scenario as deceitful while many terriers interpreted it as motivated by the intention to show something new. Marshall-Pescini et al. [45] suggested that the intentions behind human actions might play an important role in causing dogs’ social bias (i.e. the tendency to make counterproductive choices under the influence of human signalling). From our findings, it seems possible that artificial selection made cooperative workers more skilled at detecting human deception relative to independent workers. Indeed, it has been suggested that one of the necessary conditions for the emergence of reciprocal altruism is that the cooperating animals need to be able to recognize cheaters [72]. However, to test this hypothesis, future research is needed to target specifically the reaction of a larger sample of other ‘independent workers' (e.g. sled dogs, hounds and greyhounds) to this task.

The evolutionary origin of dogs' ability to distinguish between TB and FB of humans remains an open question. Future studies should examine how dogs and wolves (Canis lupus) compare in the current paradigm. If dogs’ increased attention to human mental states results from the process of domestication, wolves are not likely to perform similarly to dogs. Additionally, future research should clarify based on broader phylogenetic comparisons (e.g. comparing dogs with other domesticated species or primate species) whether identical or only superficially similar mechanisms have evolved across species and taxa.

In conclusion, our study provides the first experimental evidence that dogs distinguish between a TB and a FB condition in a change-of-location task. Although in both conditions the communicator suggested the empty container, different numbers of dogs in the two groups followed this cue. For most dog breeds, this response pattern was in contrast to those found in human infants and great apes—with the notable exception of the terrier breed group. This raises the possibility that pet dogs attribute to human informants, in the absence of any training, not only different knowledge states, but also different intentions and beliefs. Distraction [20] is very unlikely to account for this finding. Indeed, not only the good performance in the familiarization phase but also the fact that the majority of dogs in experiment 1 (61.5%) and in the CTB group (72%) followed their own knowledge proved that the dogs were sufficiently attentive to find food hidden and displaced.

Based on the experience dogs made during the familiarization phase that the communicator's suggestion was trustworthy, the cueing of the empty container in the test has likely caused a conflicting information for the dogs. A possible account for the difference between FB and TB groups in dealing with this misleading suggestion by the human informant is in terms of mental state attribution. In the FB group, a decent number of dogs from cooperative breeds might have followed the wrong suggestion of the informant by attributing to her a FB and consequently a ‘justified’ mistake in good will. However, in the TB groups, a lower number of dogs followed the same suggestion because this appeared deceitful or at least unjustified based on the informant's epistemic state. By contrast, dogs from more independent breeds like terriers may have interpreted the TB informant's suggestion as invitation to explore the first hiding place further and therefore relatively more terriers of the TB group followed it. Of course, such mentalistic accounts in terms of how the situation appears from the communicator's perspective and what the intention of the communicator is when suggesting the wrong container, would need additional evidence from experiments with specific controls for other accounts (behavioural rules, ignorance, submentalizing, minimalist accounts, experiential record-keeping and awareness relations; see [6,18,20,49]). Until that, the possibility that dogs possess what seems at least an implicit FB understanding remains an exciting hypothesis.

Do We Still Believe There Is a G-spot? The never-ending search to find, literally, a spot, a magic button delivering a unique orgasmic experience produced evident harm for the whole field of sexual medicine

Do We Still Believe There Is a G-spot? Daniele Mollaioli, Andrea Sansone, Elena Colonnello, Erika Limoncin, Giacomo Ciocca, Linda Vignozzi & Emmanuele A Jannini. Current Sexual Health Reports, July 27 2021. https://rd.springer.com/article/10.1007/s11930-021-00311-w

Abstract

In the field of female sexuality, the existence of the so-called “G-spot” represents a topic still anchored to anecdotes and opinions and explained using non-scientific points, as well as being overused for commercial and mediatic purposes.

Purpose of Review: The scope of this review is to give an update on the current state of information regarding the G-spot and suggesting potential future directions in the research field of this interesting, albeit controversial, aspect of human sexual physiology.

Recent Findings: From evolutionary, anatomical, and functional points of view, new evidence has rebutted the original conceptualization of the G-spot, abandoning the idea of a specific anatomical point able to produce exceptional orgasmic experiences through the stimulation of the anterior vaginal wall, the site where the G-spot is assumed to be. From a psychological perspective, only few findings to date are able to describe the psychological, behavioral, and social correlates of the pleasure experience by G-spot-induced or, better, vaginally induced orgasm (VAO).

Summary: Recent literature suggests the existence of a G-spot but specifies that, since it is not a spot, neither anatomically nor functionally, it cannot be called G, nor spot, anymore. It is indeed a functional, dynamic, and hormone-dependent area (called clitorourethrovaginal, CUV, complex), extremely individual in its development and action due to the combined influence of biological and psychological aspects, which may trigger VAO and in some particular cases also female ejaculation (FE).

Conclusions

The topic of the G-spot is to date, most likely, a unique controversial aspect of human gross-anatomy. There are three main reasons for it (Fig. 1). The first was choosing the wrong name. Although it recognizes the debt to Ernst Gräfenberg who pioneered the studies on human vagina, it should be said that the term “spot” following the initial of his last name produced a holy grail: a never-ending search to find, literally, a spot, a magic button delivering a unique orgasmic experience, which — this is absolutely true — does not exist. Unfortunately, the conundrum on the existence of such a spot has been very largely discussed by non-scientific media and, on many occasions, by review articles based on opinions. This produced evident harm for the whole field of sexual medicine.

Fig. 1

An infographic explaining the three reasons to abandon G-spot definition. Firstly, the term “G” and “Spot” are surpassed by new evidence highlighting a dynamic organization between the structures of female genitalia (clitoris, urethra, and vagina). Secondly, a conceptualization of the vagina as an “inert tube” should be abandoned due to its high sensitivity to hormone action and active role in sexual pleasure and orgasm; Finally, the anatomical-functional structure of female genitalia cannot be considered universal but extremely variable in its functioning owing to the action of hormones, cognitive, and emotional status and even partner’s characteristics

There is a second element which produced skepticisms. In several gynecological settings, the vagina has been considered no more than an inert tube for delivering babies. Some surgeons base their wrong assumption on the idea that the vagina, designed for this purpose, must be then poorly innervated and almost not sensitive. Of course, this position ignores the role of the numerous hormonal and neurotransmitter changes during the last hours of pregnancy and delivery. An excellent representation of the ignorance of some gynecologists has been well represented by the symphysiotomy, or Zarate’s operation [84], and by the episiotomy itself [85, 86]. The two operations are very rarely needed, and the large majority of these interventions done in the past were based on ignorance, misogyny, and prejudices against female sexuality. Nowadays, the argument that the vagina is just a fibromuscular channel, sexually inert, is no longer tenable. In other words, if the vagina is a sexual organ, particularly responsive in its anterior wall, the G-spot, or however it is called, is a reality.

The third reason generating the controversy can be found in the characteristics of the main actors of this anatomical region. The clitoris, urethra, female prostate, and vagina are exquisite hormone-dependent areas in their size, gross anatomy, histology, and function [87]. Moreover, nothing is more fluctuating than (steroid) hormones in females. Is this sufficient to admit that this region is definitively not universal in its anatomic and functional structure? Is this enough to admit that the findings denying the G-spot in a single or few cases are, at the very least, inconclusive? The surprising variations from woman to woman in referring to and experiencing arousal and orgasm, the dramatic differences in the same woman regarding the same experiences according to the various phases of the menstrual cycle or the reproductive/perimenopausal/postmenopausal status may suggest more humility when deciding that the G-spot does not exists (but also that every woman must have it).

But there is another, although para-scientific, argument which should be considered when attempting to answer the question embedded in the title of this article. The Italian version of Amazon is currently selling around 1000 different vibrators, 218 of them claiming to be able, due to shape and functionalities, to directly stimulate the G-spot. Shall we consider the fact that one out of every four buyers looking for a G-spot sexual aid is a victim, totally influenced by the wrong mediatic messages? If those tools do not work for the simple reason that the G-spot does not exist, their market would crash rapidly. The fact that it is a prosperous market, and that the haptic stimulation of the debated region is considered a plus of these tools [88], would suggest that the CUV area should deliver some pleasure, if not orgasms, when properly stimulated.

Despite all these reasons, it seems evident that the questions about the existence of the G-spot have not yet been definitively answered, as well as the question of the nature of FE and the existence of more than one female orgasm. However, it is important that the topic is finally addressed in a scientifically appropriate way, as the most recent studies [49] have improved our understanding of the complex anatomy and physiology of the female sexual response. On the other hand, the other aspects influencing the perception and the orgasmic experience connected to the G-spot remain in most cases anecdotal or understudied.

This intriguing topic, which finds explanatory roots in several disciplines (anatomy, physiology, psychology, sexology, history, evolution, anthropology, and sociology), will have to be studied for a long time with an even more scientific approach. However, we have here to conclude that the G-spot surely exists and is present, developed, and active on a tremendously individual basis. However, it is not a spot, and to reduce the risks of misinterpretations and vacuous discussions, it cannot be called G anymore. It is indeed a functional, hormone-dependent area, which may trigger VAOs and in some cases also FEs, well defined as CUV.

In the no-command condition participants almost always crashed the drone on the military site (96%), whereas in the command condition they chose to obey & sacrifice civilians to protect the military material 33% of the time

The Dilemma Of Disobedience: An ERP study. Eve F. Fabre, Mickaël Causse, Maryel Othon, Jean-Baptiste Van Der Henst. bioRxiv, Jul 5 2021. https://doi.org/10.1101/2021.07.05.451127

Abstract: The present experiment aimed at investigating the decision-making and the associated event-related potentials (ERPs) of subordinates under hierarchical pressure. Participants (N = 33) acted as UAV operators and had to decide to crash their defective drone either on a civilian site killing all civilians present on the site or on a military site destroying military material but preventing any human losses. While in the no-command condition, participants decided according to their own preferences, in the command condition they were ordered to protect the military material at the expense of civilians for undisclosed strategic reasons. The results revealed that in the no-command condition participants almost always crashed the drone on the military site (96%), whereas in the command condition they chose to obey orders and sacrifice civilians to protect the military material 33% of the time. In the command condition, participants were longer to make their decisions, mobilizing greater attentional and cognitive resources (i.e., greater P300 responses) to resolve the conflict between their internal moral values and the orders they were given (i.e., greater N200 responses) than in the no-command condition, where they automatically applied the “you shall not kill” rule. Participants also showed a greater negative affective response (i.e., greater P260 amplitudes) after choosing to disobey than to obey orders. This result suggests that disobeying authority could be perceived as a greater moral violation than obeying and sacrificing civilians, suggesting that individuals may sometimes choose to obey malevolent authority to avoid the negative affective reaction triggered by disobedience.

After Trump's victory: Republican-leaning counties experience a sharp & persistent increase in fertility relative to Democratic counties: a 1.1 to 2.6 pct point difference in annual births, depending on the intensity of partisanship

Partisan Fertility and Presidential Elections. Gordon Dahl, Runjing Lu & William Mullins. NBER Working Paper 29058. DOI 10.3386/w29058. Jul 2021. https://www.nber.org/papers/w29058

Abstract: Changes in political leadership drive large changes in economic optimism. We exploit the surprise 2016 election of Trump to identify the effects of a shift in political power on one of the most consequential household decisions: whether to have a child. Republican-leaning counties experience a sharp and persistent increase in fertility relative to Democratic counties: a 1.1 to 2.6 percentage point difference in annual births, depending on the intensity of partisanship. Hispanics, a group targeted by Trump, see fertility fall relative to non-Hispanics, especially compared to rural or evangelical whites. Further, following Trump pre-election campaign visits, relative Hispanic fertility declines.

Cross-Cultural Measurement Invariance in the Personality Inventory for DSM-5: Examination in several cultural environments or countries

Cross-Cultural Measurement Invariance in the Personality Inventory for DSM-5. M.A. Sorrel et al. Psychiatry Research, July 22 2021, 114134. https://doi.org/10.1016/j.psychres.2021.114134

Highlights

• It is again evidenced that the loading structure of the PID-5 is very complex

• Partial scalar invariance was supported which allowed for factor means comparisons

• The domain where the differences were greatest was psychoticism

• The influence of non-invariant items found to be was minimal

Abstract: The validity of cross-cultural comparisons of test scores requires that scores have the same meaning across cultures, which is usually tested by checking the invariance of the measurement model across groups. In the last decade, a large number of studies were conducted to verify the equivalence across cultures of the dimensional Alternative Model of Personality Disorders (DSM-5 Section III). These studies have provided information on configural invariance (i.e., the facets that compose the domains are the same) and metric invariance (i.e., facet-domain relationships are equal across groups), but not on the stricter scalar invariance (i.e., the baseline levels of the facets are the same), which is a prerequisite for meaningfully comparing group means. The present study aims to address this gap. The Personality Inventory for DSM-5 (PID-5) was administered to five samples differing on country and language (Belgium, Catalonia, France, Spain, and Switzerland), with a total of 4,380 participants. Configural and metric invariance were supported, denoting that the model structure was stable across samples. Partial scalar invariance was supported, being minimal the influence of non-invariant facets. This allowed cross-cultural mean comparisons. Results are discussed in light of the sample composition and a possible impact of culture on development of psychopathology.

Keywords: personality disordersDSM-5PID-5factor analysismeasurement invariance

3. Discussion

The present study provides evidence for the measurement invariance of the PID-5 across the cultures examined. This pattern concurs with Thimm et al. (2016)’s results which indicated that the scale was also invariant across United States and Norwegian samples. Since Thimm et al. analyzed university students only, they claimed that a more heterogeneous sample with a larger variety of age, educational level, and socioeconomic status should be analyzed in the future to test the cross-cultural stability of the structure of PID-5. Although university students were also analyzed in the present study, two samples came from the general population. Considering that findings from the present paper are more generalizable, the limitation of the composition of the sample is somewhat surpassed. Note also that no sharp differences in the structure were found between university (French-speaking samples) and community samples (Spanish and Catalonian samples). As in Thimm et al.’s study, some intercepts had to be released. These results imply that if different groups are to be compared, the more appropriate approach would be comparing the latent factor means. However, as the practical influence of the non-invariant items was shown to be minimal, observed scores might be also interpreted with caution. This adds to previous evidence showing that PID-5 domain scores can also be compared by sex and clinical status (Bach et al., 2017; Suzuki et al., 2019).

3.1. What could Explain the Differences in Intercepts and Means?

Differences in the intercepts and the latent means can be caused by two reasons. The first one would be variations on the sample composition. Note that samples from the community settings (Spanish and Catalonian ones) generally presented the lowest mean differences, and that some of the two largest differences were observed between the French and Belgium (university setting) and both Spanish and Catalonian samples for the Disinhibition domain. Besides, there were large differences in the age distribution. French-speaking samples were younger than the Spanish and Catalonian ones. It is a well-established fact that age has an impact on Disinhibition and related constructs as Sensation seeking (Steinberg et al., 2008), with younger subjects showing higher levels of Disinhibition (Zuckerman, 1994). That would be against other authors like Debast et al. (2018) who state that PID-5 is mostly age neutral. Samples also differed in terms of sex distribution with French-Speaking samples being composed mostly by females, and Spanish and Catalonian samples showing a more balanced distribution. Since women score higher on Neuroticism (Costa et al., 2001) and lower on Disinhibition and Sensation Seeking (Zuckerman, 1994), differences between all French-Speaking samples and Spain and Catalonian can be expected on these two domains. This pattern was observed for the comparisons with Belgium and France, but not with Switzerland. Besides, the previous study by Suzuki et al. (2019) explicitly examined the issue of gender invariance measurement for PID-5, finding that the scale was equivalent across sex. In summary, there is some room to support the hypothesis that the differences in the means may be due to variations in sample composition.

The second explanation of the differences across samples implies the presence of a real impact of the culture in the development of psychopathology. From this standpoint, culture may play a role in determining the exact behavioral and contextual formulation of some maladaptive behaviors and psychopathological manifestations (Terracciano & McCrae, 2006). The fact that differences on factor means were not homogeneous across samples with a similar composition (French-Speaking university samples), and that the samples from the same country (Spain) were generally similar in their latent means, suggests that culture may play a relevant role to explain differences on personality disorders. The five samples came from four different countries (i.e., Belgium, France, Spain, and Switzerland). The most widespread framework for comparing cultures is the six-dimensional classification generated by Hofstede (e.g., Hofstede, 2011). This model postulates six dimensions: power distance, uncertainty avoidance, masculinity vs. femininity, long term vs. short term orientation, and individualism vs. collectivism. Arguably, this last dimension has received the most attention in previous personality literature (e.g., Mulder, 2012; Triandis, 2001). According to Hofstede Insights dataset (Hofstede, 2018), Belgium, France, and Switzerland score similarly in the Individualism-collectivism dimension (75, 71, and 68, respectively), while the score for Spain is markedly lower (51). It has been suggested that a possible consequence of the individualistic culture on personality is to encourage the development of distinct/unique attitudes, self-definition, and striving to attain personal goals (Mulder, 2012). This is somewhat congruent with the fact that France obtained the highest mean in Disinhibition and Spain the lowest. The existence of cohort effects is often cited as an argument for the influence of social and cultural factors on personality. For example, the antisocial behavior profile maintains an upward trend and has doubled in value since World War II (Kessler et al., 1994). However, it should be recalled here that studies linking culture and personality are still scarce, so that the hypotheses put forward should be taken with caution.

3.2. Concluding Remarks on the PID-5 Factor Loading Structure

The loading solution was very similar to that reported by the two available meta-analyses (Somma et al., 2019; Watters and Bagby, 2018). It is again evidenced that the factorial structure of PID-5 is complex, with multiple cross loadings. Specifically, 30 out of 100 possible secondary loadings had a factor loading greater than .20 in absolute value. Only 8 out of the 25 facets (32%) did not present any secondary loading greater than .20 in absolute value (i.e., Emotional lability, Separation insecurity, Submissiveness, Withdrawal, Intimacy avoidance, Manipulativeness, Irresponsibility, and Unusual beliefs and experiences). The most complex facets were Rigid perfectionism and Risk taking. This complex structure might have serious implications for assessment utility (discriminant validity) and theory (Crego et al., 2015; Watters et al., 2018). While some of these secondary loadings can be supported from a theoretical standpoint (e.g., Risk-taking has been related to Negative Affect, Disinhibition and Antisocial behaviour patterns; Aluja et al., 2007), in general, it draws attention to the fact that a revision of the instrument would probably be necessary to reach the most discriminant structure with theoretical meaning.

3.3. Limitations and Future Directions

The present work is not without limitations. The reported fit values are adequate considering previous literature on the PID-5, but again serve to illustrate that it is difficult to obtain excellent fit values when exploring factor structure in the areas of personality and personality disorders. Authors such as Hopwood and Donnellan (2010) have argued that it is to be expected that it would not be easy to achieve excellent model-data fit, given how easy it is to find items with similar phrasing or other methodology artifacts (e.g., acquiescence). It is expected that modelling these factors will lead to a better fit (Abad et al., 2018). Yet, it is important to remember that this is one of the sources of validity evidence available to support the interpretation and use of the scale scores. The fact that adequate evidence of criterion-referenced validity for the PID-5 scores is reported in prior research also contributes to that purpose (Al-Dajani et al., 2016). As for the analysed samples, all of them came from European Western cultures. In the personality field, Allik et al. (2017) and Aluja et al. (2020) found that similar cultures seem to have similar mean personality profiles. The present study supports this idea also would apply in the context of pathological personality, as most of the effect sizes of differences between countries did not reach a medium effect size, and latent means for Spanish and Catalonian samples were generally similar. It is possible that incorporating non-European Western cultures could change this pattern of cross-cultural stability of the structure, although some other studies suggest a stability beyond western cultures (Rossier et al., 2008). Another limitation is that the current study used only a nonclinical sample. However, the available research seems to indicate that this is not a major concern since prior studies found that the results at the domain level obtained in non-clinical samples might be generalized to clinical populations (Bach et al., 2018).

Putting the cart before the horse: claims for mirror self-recognition in horses are unfounded

Putting the cart before the horse: claims for mirror self-recognition in horses are unfounded. Gordon G. Gallup Jr. & James R. Anderson. Animal Cognition, Jul 27 2021. https://rd.springer.com/article/10.1007/s10071-021-01538-9

Abstract: The recent article by Baragli, Scopa, Maglieri, and Palagi (Anim Cogn https://doi.org/10.1007/s10071-021-01502-7, 2021) that claims to demonstrate mirror self-recognition (MSR) in horses is not based on compelling evidence. We identify problems with their experimental procedures, data, and assertion about “demonstrating MSR at group level.” Examples of these problems include incomplete experimental design, absence of important control conditions, inappropriate terminology, suboptimal mark application procedures and coding of videos, ambiguity of videos presented as supporting evidence, and inconsistencies in data presentation and interpretation. It is not the case that their study “marks a turning point in the analytical technique of MSR exploration.”

Strangers Look Sicker (with Implications in Times of COVID-19)

Bressan, Paola. 2021. “Strangers Look Sicker (with Implications in Times of COVID-19).” PsyArXiv. July 26. doi:10.1002/bies.202000158

Abstract: We animals have evolved a variety of mechanisms to avoid conspecifics who might be infected. It is currently unclear whether and why this “behavioral immune system” targets unfamiliar individuals more than familiar ones. Here I answer this question in humans, using publicly available data of a recent study on 1969 participants from India and 1615 from the USA. The apparent health of a male stranger, as estimated from his face, and the comfort with contact with him were a direct function of his similarity to the men in the local community. This held true regardless of whether the face carried overt signs of infection. I conclude that our behavioral immune system is finely tuned to degrees of outgroupness—and that cues of outgroupness are partly processed as cues of infectiousness. These findings, which were consistent across the two cultures, support the notion that the pathogens of strangers are perceived as more dangerous.

Potential for Collaboration: Differences Between Evolutionary Anthropology and Evolutionary Psychology as Scientific Disciplines

Hahnel-Peeters, Rebecka K. 2021. “Potential for Collaboration: Differences Between Evolutionary Anthropology and Evolutionary Psychology as Scientific Disciplines.” PsyArXiv. July 20. doi:10.31234/osf.io/kp4rc

Abstract: In a review of evolutionary analysis of human behavior, Alden Smith (2000) argues that evolutionary anthropology and evolutionary psychology should not be considered competing disciplines. If evolutionary anthropology and psychology were to become more collaborative, it would aid our understanding of human nature – regardless of the different assumptions and empirical methodology used by the two disciplines. The recent 10th anniversary of “The WEIRDEST people in the world” (Henrich et al, 2010) presents a good opportunity to assess the current state of the evolutionary social sciences. While scholars (e.g., Barrett, 2020) have provided thoughts on the future direction of the evolutionary social sciences, none have explicitly evaluated the degree to which the various subdisciplines within the evolutionary social sciences have moved toward greater collaboration over the past decade. The current study uses content analysis to systematically examine if the disciplines of evolutionary anthropology and psychology are becoming more collaborative by reporting the frequency of coauthored peer-reviewed papers published in Evolution and Human Behavior (EHB), the type of data, and the empirical methodology used in these papers. A total of 737 articles published in EHB between 2009 and 2020 were coded, and no evidence of increased frequency of anthropologist and psychologist collaborations was found. While evolutionary anthropologists and psychologists did not report different types of data or topics of interest, the methods for hypothesis testing were different. I discuss limitations for the current content analysis and review suggested future steps for unification.

Domestic cats (Felis catus) prefer freely available food over food that requires the slightest effort

Domestic cats (Felis catus) prefer freely available food over food that requires effort. Mikel M. Delgado, Brandon Sang Gyuc Han & Melissa J. Bain. Animal Cognition, Jul 26 2021. https://rd.springer.com/article/10.1007/s10071-021-01530-3

Abstract: Contrafreeloading is the willingness of animals to work for food when equivalent food is freely available. This behavior is observed in laboratory, domesticated, and captive animals. However, previous research found that six laboratory cats failed to contrafreeload. We hypothesized that cats would contrafreeload in the home environment when given a choice between a food puzzle and a tray of similar size and shape. We also hypothesized that more active cats would be more likely to contrafreeload. We assessed the behavior of 17 neutered, indoor domestic cats (Felis catus) when presented with both a food puzzle and a tray across ten 30-min trials. Each cat wore an activity tracker, and all sessions were video recorded. Cats ate more food from the free feed tray than the puzzle (t (16) = 6.77, p < 0.001). Cats made more first choices to approach and eat from the tray. There was no relationship between activity and contrafreeloading, and there was no effect of sex, age, or previous food puzzle experience on contrafreeloading. Our results suggest that cats do not show strong tendencies to contrafreeload in the home environment, although some cats (N = 4) ate most food offered in the puzzle or showed weak contrafreeloading tendencies (N = 5). Eight cats did not contrafreeload. Cats who consumed more food from the puzzle, consumed more food in general, suggesting a relationship between hunger and effort. Further research is required to understand why domestic cats, unlike other tested species, do not show a strong preference to work for food.

Discussion

In this study, we tested for the first time whether domestic cats living in homes would contrafreeload, as has been demonstrated in several captive and domesticated species. We did not find strong evidence for contrafreeloading; instead, cats preferred to eat the food that was freely available with no required additional effort. This was true when looking at both the overall population of cats, and the behavior of individual cats across trials.

We were unable to identify specific individual traits (sex, age and previous experience with a food puzzle) that predicted whether cats would contrafreeload. The four cats who appeared to be contrafreeloaders had one trait in common; they ate most of the food available to them during trials. In fact, the strongest predictor of amount of food eaten from the puzzle was the amount of food eaten from the tray.

The unanswered question is why cats, among multiple species tested, appear to be the only one that does not reliably contrafreeload. This tendency appears to contradict the fact that cats naturally work for food by hunting and will stop eating to hunt additional prey (Adamec 1976; Leyhausen 1979). Some differences in contrafreeloading tendencies among species have been attributed to domestication, such as in one study where white leghorn layers contrafreeloaded less than their ancestral species, jungle fowl (Jensen et al. 2002). Possible explanations included selection for allocation of resources toward reproduction and individual growth, and less need for information gathering when food sources are stable.

The cats in our study were all spayed or neutered and housed indoors only, which might have impacted their behavior. Spaying and neutering decreases the metabolic rate (Fettman et al. 1997) and the physical activity of female cats (Belsito et al. 2009), while simultaneously increasing cats’ food intake (Alexander et al. 2011; Wei et al. 2014). However, the previous study that failed to find evidence of contrafreeloading in cats only included reproductively intact cats (Koffer and Coulson 1971). To date, no studies have directly compared the activity patterns of indoor cats with those who have outdoor access. Thus, it would be premature to predict different results from reproductively intact or outdoor cats.

We also found no relationship between activity and contrafreeloading behavior. This result supports a previous study that found no change in activity level after introducing food puzzles to cats (Naik et al. 2018). Another study found that when two laboratory cats were required to offer an increasing number of touches to a switchplate in exchange for free access to food, they decreased the number of meals per day, and consumed more food at each feeding period (Collier et al. 1997). Studies of free-roaming feral cats suggest they spend almost 90% of their time inactive, with < 1% of their time spent hunting (Hernandez et al. 2018). In general, cats appear to conserve energy to the greatest extent possible, minimizing the amount of time and effort required to meet their caloric requirements, whether by hunting or engaging with enrichment devices in homes.

Our conclusion that cats prefer freely available food over that which requires effort is limited by some aspects of our study, such as a relatively small sample size. It is possible that the appearance of the food puzzle hindered consumption, as food was more visible in the tray. However, the cover of the puzzle was translucent, and several of the compartments face upward, such that the food would be visible from above. Although the novelty or shape of the food puzzle could have been a deterrent to the cats, we controlled for this by presenting all cats with a novel tray of the same shape and size simultaneously. All cats ate from both the puzzle and the tray during the training period, so we do not believe that appearance, novelty, or aversion to the device itself can explain the failure to contrafreeload.

We also did not control for food intake or hunger, as we did not want to increase the stress levels of cats, who can be sensitive to changes in feeding regimens (Stella et al. 2011). Food restriction can also reduce contrafreeloading (Inglis et al. 1997), so we did not want food withheld from cats longer than they were accustomed to. Since the cats ate a large percentage of the freely available food during trials, we cannot blame the failure to contrafreeload on a lack of interest in food. However, as we only gave cats access to the tray and puzzle for 30 min per trial, it is possible that cats would have engaged more with the puzzle if it continued to be available throughout the day.

Interpretation of our results may be dependent on how contrafreeloading is defined. Sometimes contrafreeloading is defined as when an animal will work for any food in the presence of freely available food, whereas some consider it a preference to work for food (Inglis et al., Osborne et al.). Most cats in our study did eat some food from the puzzle but none ate more food from the puzzle than the tray. Thus, although we have evidence for some willingness to work for food when freely available food is present (weak contrafreeloading), there is no evidence that cats preferred to work for food.

Of the species who have been tested for contrafreeloading, few predatory species (chimps, humans, and cats) are included, and most species tested are foragers who use extended search to acquire food (e.g., pigeons, rats, gerbils, Inglis et al. 1997). Sit-and-wait predation is considered low cost and is a common hunting style among felids (Williams et al. 2014). A full discussion of predatory energetics is beyond the scope of this manuscript, but contrafreeloading, which provides information about the quality of food patches, is expected to be weaker in species that do not engage in prolonged search (Inglis et al. 1997). Future studies should investigate whether foraging style is an important factor in contrafreeloading tendencies, and whether energy conservation is influential.

Like other studies, we did not find a statistically significant effect of sex on contrafreeloading (Lindqvist and Jensen 2008; Vasconcellos et al. 2012). However, in the current study, the four cats who did show a tendency to contrafreeload were all males, and the two cats who did not eat any food from the puzzle were both females. Male cats are more prone to obesity (Lund et al. 2005) and may be more food motivated in general. Our findings suggest the sex of the cat should be considered in future studies.

Future research can further explore contrafreeloading in cats by introducing different types of food puzzles or operant behaviors necessary for obtaining food. Changing the value of the food offered may also increase contrafreeloading, as novelty of food items increases the level of reinforcement (Inglis et al. 1997). The effects of foraging enrichment on cat welfare and health indicators should also be assessed. A presentation of case studies found positive effects of food puzzles for domestic cats, such as weight reduction and an improvement of behavioral health (Dantas et al. 2016), but puzzles do not appear to increase overall activity levels (Naik et al. 2018).

Understanding contrafreeloading is important for captive and domestic animal welfare as foraging enrichment is a frequently used tool to provide choice and mental stimulation. The effects of such enrichment on the behavior of captive animals are rarely tested. For domestic cats, the provision of foraging enrichment may depend on the needs and food motivation of the individual animal, and may be best introduced as a choice to enhance welfare, as foraging enrichment has been suggested to do in other species (e.g., Tarou and Bashaw 2007).