Sunday, July 18, 2021

Understanding the onset of hot streaks across artistic, cultural, and scientific careers

Understanding the onset of hot streaks across artistic, cultural, and scientific careers. Lu Liu, Nima Dehmamy, Jillian Chown, C. Lee Giles, Dashun Wang. arXiv Mar 2021.

Hot streaks dominate the main impact of creative careers. Despite their ubiquitous nature across a wide range of creative domains, it remains unclear if there is any regularity underlying the beginning of hot streaks. Here, we develop computational methods using deep learning and network science and apply them to novel, large-scale datasets tracing the career outputs of artists, film directors, and scientists, allowing us to build high-dimensional representations of the artworks, films, and scientific publications they produce. By examining individuals' career trajectories within the underlying creative space, we find that across all three domains, individuals tend to explore diverse styles or topics before their hot streak, but become notably more focused in what they work on after the hot streak begins. Crucially, we find that hot streaks are associated with neither exploration nor exploitation behavior in isolation, but a particular sequence of exploration followed by exploitation, where the transition from exploration to exploitation closely traces the onset of a hot streak. Overall, these results unveil among the first identifiable regularity underlying the onset of hot streaks, which appears universal across diverse creative domains, suggesting that a sequential view of creative strategies that balances experimentation and implementation may be particularly powerful for producing long-lasting contributions, which may have broad implications for identifying and nurturing creative talents.


Individual behavior At the individual level, the ‘essential tension’ hypothesis by Thomas Kuhn [60] illustrates the choice between exploiting existing ideas and exploring newyet risky opportunities. The sociology of science offers severalfundamentaltheoretical discussions [61,62]. Morerecently, empiricalanlaysishasbeenconductedtoquantitatively understand the ‘essential tension’ hypothesis. For example, Foster et al. [53] analyzed millions of abstracts from MEDLINE, and identified topics from the clusters on the chemical networkto trace the researchstrategy ofbiomedical researchers [63]. In addition,thePACS code in American Physical Society (APS) dataset has also been widely used to quantify exploration and exploitation for scientific careers [18, 52, 64].

Researchers have also studied various environmental, social and individualfactors that may influence one’s choice between exploration and exploitation [48]. Environmentalfactors include resource status of a local position [49, 65], cost and reward of exploration and exploitation [65, 66], available information on different options [67], and more. Discussions centered around how long individuals should stay in the exploitation/exploration phase and when to change their behaviors under different environmental settings. For example, the probability of exploration increases when the resource is depleted, when the cost of exploration decreases, or when individuals are uncertain about the options. The social factors are widely discussed in social learning strategies and collective intelligence [68–72], ranging fromtask complexity [73], to past success and failure [71, 73]tonetwork structures [74, 75]. Individuals can update their strategies like exploration, exploitation or copying others to increase theirpayoffsunderdifferent settings.Individual factors such as personalities [76], cognitive capacity [77], and aspiration level[78], also influence one’s propensity to explore or exploit.

In the literature of strategic management and organization theory, scholars have examined exploration and exploitation behaviors ofindividuals and firms, particularly focusing ontheeffects thishasonorganizationaloutcomes. Forexample,Singh&Agrawal[79]found that when scientists begin working within a new organization, the organization increases their use of the new recruit’s prior work and that the majority of the effect is due to the employee’s own exploitation of their prior work. Groysberg & Lee [80] found that when star security analysts were hired to explore (i.e., to initiate new activities for the organization), they experienced a drop in performance; whereas star security analysts hired to engage in exploitation (i.e., to reinforce the organization’s existing activities) experienced a boost in performance. Other research has looked at the antecedents of individuals’ exploration and exploitation behaviors. For example, Lee & Meyer-Doyle [81] examined how financialincentives shapedthebehavior of salespeopleandfoundthatindividuals engaged in more exploration when performance-based incentives were weakened but this increase wasdriven by the organization’s strongestperformers. Recent study on network oscillation for bankers [82] suggests that switching between exploration and exploitation has positive effects on the employee’s network advantage.

Organization learning, design and adaptation

At the macro level, another important line of research examines exploration and exploitation in the context of organization learning, organization design, and organizational adaptation [58]. This line of work builds on the canonical work by March [57], and suggests that both exploration and exploitation are critical for an organization’s performance, but they are inherently in tension and that this tension must be actively managed [83]. This tension reflects trade-offs between short vs. long-termperformance and stability vs. adaptability [57, 84–87]. Debates in this literature center onseveralfundamental questions: Do exploration and exploitation exist as twoends of a continuum (and so cannot coexist at the same time) or are they orthogonal discrete choices? Can organizations find a balance between exploration and exploitation activities or should they specialize in one or the other? It also explores the antecedents to organizations’decisions topursue exploration or exploitation [59, 88], examining environmental factors (e.g., exogenous shocks, competitive dynamics) as well as organizational factors (e.g., culture, resources, capabilities)thatinfluence that choice. This literaturealsouses the notion of organizational ambidexterity to describe the ability to do both exploration and exploitation simultaneously [89]. Finally, this research examines the performance implications for organizations of adopting different approaches to balancing this enduring trade-off between exploration and exploitation [90]. This line of research is performed using multiple different methodologies including empirical studies using quantitative and qualitative data from organizations, theoretical models [91], and agent-based simulations [59, 92, 93].

Idea formation

At a more micro level, the discussion of exploration and exploitation is particularly relevantto studies on idea formation and innovation process [94–96], which models themechanismofinnovationas randomwalksonthenetworkofideas/landscapeof solutions. In this setting, exploration and exploitation is usually defined as creating new path or reproducing existing ideas. For example, Iacopini et al [94] models the cognitive growthofknowledgeinscienceforover20yearsandvalidateprocesswithconceptnetworks curated from WoS abstracts. Studies have shown that both existing knowledge and novel combinations are essential for producing high-impact scientific papers [97]. The discussion goes beyond science to innovation and technology as well. For example, Youn et al.[98] analyzed technology codes used byUSPTO to quantify innovation strategy,finding a constant rate of exploration and exploitation in patent records. Overall, our results contribute to these three lines of literature in several ways. First, by documenting the relationship between exploration, exploitation and career hot streaks, our results demonstrate broader relevance ofthe concepts of exploration and exploitation, extendingbeyond existing individual ororganizational settings to theunderstanding ofhot streaks and individual creative careers. At root, our results suggest the important role of both exploration and exploitation in individual careers. Curiously, across a wide range of creative domains, a major turning point for individual careers appears most closely linked withneitherexplorationnorexploitationbehaviorinisolation,butratherwiththeparticular sequence of exploration followed by exploitation, which highlights our second contribution. Indeed, extantliteraturehasdocumentedthefundamental roleofexplorationandexploitation in creativity. Yet as creative behaviors, they have traditionally been considered either in isolation [53, 60] or in combination [58, 99] but rarely in succession. Our results suggest a sequential view of creative strategies that balance experimentation and implementation may be particularly powerful for producing long-lasting contributions.

From 2020... Less Sex, but More Sexual Diversity: Changes in Sexual Behavior during the COVID-19 Coronavirus Pandemic

From 2020... Less Sex, but More Sexual Diversity: Changes in Sexual Behavior during the COVID-19 Coronavirus Pandemic. Justin J. Lehmiller, Justin R. Garcia, Amanda N. Gesselman & Kristen P. Mark. Leisure Sciences Volume 43, 2021 - Issue 1-2, Pages 295-304. Jun 26 2020.

Abstract: Recreational sex is a popular form of leisure that has been redefined by the COVID-19 (coronavirus) pandemic. “Social distancing” rules have imposed limits on sex for leisure while also creating new opportunities. We discuss results from an online survey of 1,559 adults who were asked about the pandemic’s impact on their intimate lives. While nearly half of the sample reported a decline in their sex life, one in five participants reported expanding their sexual repertoire by incorporating new activities. Common additions included sexting, trying new sexual positions, and sharing sexual fantasies. Being younger, living alone, and feeling stressed and lonely were linked to trying new things. Participants making new additions were three times more likely to report improvements in their sex life. Even in the face of drastic changes to daily life, many adults are adapting their sexual lives in creative ways.

Keywords: coronavirusCOVID-19sexual behaviorsexual noveltysocial distancing


The COVID-19 pandemic is impacting people’s sexual lives. This is evidenced in our initial empirical multinational data on the impact of lockdowns and physical distancing restrictions on people’s intimate lives. These findings are consistent with a smaller simultaneous study demonstrating a decrease in sexual frequency among a sample of young adults in China (Li et al., 2020), but they differ from a report of married people in Southeast Asia who reported unspecified changes in their sexual life but not decreases in sexual frequency (Arafat et al., 2020). Although our sample is not representative and caution is warranted in generalizing broadly, these findings nonetheless make an important and novel contribution to the literature and to our collective understanding of the influence of the COVID-19 pandemic and physical distancing on sociality, leisure, and sex.

There are several important implications of this work. While a majority of our participants reported no new additions to their sex lives, a substantial minority did. This finding adds much-needed complexity and nuance to the popular media narrative surrounding sex during this unusual time. It is clear that many people’s sex lives are undergoing a revolution of sorts, in which they are expanding their sexual repertoires; however, this does not appear to be as widespread and as laser-focused on SexTech as the media suggest. In fact, the single most common new addition did not require any technology at all: trying a new sexual position. This suggests that the changes going on in people’s intimate lives are broader in scope than assumed.

We also found that more participants said their sex lives declined rather than improved—and while incorporating new activities into one’s sex life was linked to improvements, new additions did not eliminate declines. Generally, only partnered activities were linked to improvements, with few technology-based activities showing any association. The new additions most strongly correlated with sex life improvement were trying new positions, acting on fantasies, engaging in BDSM, and giving massages. By contrast, the most common technology-based additions (sexting, sending nudes) were unrelated to sexual improvements. This suggests that while incorporating more technology into one’s sex life was common, it did not appear to have been as gratifying as in-person activities.

Consequently, we caution against premature claims that the COVID-19 pandemic will necessarily usher in widespread SexTech use, recreationally and otherwise. It is possible that recent uptake of SexTech is a temporary coping strategy and that once the pandemic subsides, technology usage may decrease in favor of in-person, partnered interactions.

By understanding factors associated with sexual improvements during this unprecedented time, we are also able to identify factors that might help people better navigate their intimate lives and safely pursue leisure activities during future emergency situations. For example, encouraging more novel sexual pursuits with a partner may be a helpful and therapeutic strategy for persons in relationships, particularly those feeling stressed or lonely. Likewise, the fact that SexTech was largely unrelated to sexual improvements points to important areas for future research and education. Are there ways of making these interactions more satisfying? Can SexTech education make usage more fulfilling?

The widespread social restrictions put in place during the COVID-19 pandemic appear to have significantly disrupted sexual routines and the overall quality of people’s sex lives. However, even in the face of these drastic changes, it is apparent that many adults are finding creative ways to adapt their sexual lives, including in the pursuit of sex for leisure.

Mask-wearing improved wearers’ sense of the attractiveness of faces, which were rated as less attractive when a mask was not worn after the onset of COVID-19; also, were rated as more healthy after onset

Effects of Masks Worn to Protect Against COVID-19 on the Perception of Facial Attractiveness. Miki Kamatani et al. i-Perception, June 27, 2021.

Abstract: Wearing a sanitary mask tended, in the main, to reduce the wearer’s sense of perceived facial attractiveness before the COVID-19 epidemic. This phenomenon, termed the sanitary-mask effect, was explained using a two-factor model involving the occlusion of cues used for the judgment of attractiveness and unhealthiness priming (e.g., presumed illness). However, these data were collected during the pre-COVID-19 period. Thus, in this study, we examined whether the COVID-19 epidemic changed the perceived attractiveness and healthiness when viewing faces with and without sanitary masks. We also used questionnaires to evaluate beliefs regarding mask wearers. We found that the perception of mask-worn faces differed before versus after the onset of the COVID-19 epidemic. Specifically, mask-wearing improved wearers’ sense of the attractiveness of faces, which were rated as less attractive when a mask was not worn after the onset of the COVID-19 epidemic. Furthermore, mask-worn faces were rated as healthier after the onset of the COVID-19. The proportion of respondents with negative associations regarding mask-wearing (e.g., unhealthiness) decreased relative to before the epidemic. We suggest that the weakening of this association altered the sanitary-mask effect with a relative emphasis on the occlusion component, reflecting the temporal impact of a global social incident (the COVID-19 epidemic) on the perception of facial attractiveness.

Keywords: sanitary mask, COVID-19, facial attractiveness, healthiness

In this study, we investigated the impact of the COVID-19 epidemic on beliefs regarding sanitary mask wearers as well as the perceived attractiveness of mask-worn faces by comparing data collected pre- and post-COVID-19-onset in Japan. Study 1 revealed that beliefs regarding sanitary mask wearers during the COVID-19 period differed from those in the pre-COVID-19 period. Specifically, the number of respondents who reported that they felt mask wearers were unhealthy decreased regardless of the mask color. Instead, the number of respondents who rated mask wearers as neutral or healthy increased. This change in belief was strengthened by the disappearance of the sanitary-mask effect after the onset of the epidemic, as shown in Study 2. During the pre-COVID-19 period, mask wearers were perceived as less attractive in general. This indicates that the discount in perception of attractiveness caused by mask-wearing was larger for baseline attractive faces and smaller or negligible for baseline unattractive faces (Miyazaki & Kawahara, 2016). This discounted perception did not occur for baseline unattractive faces in this study. Instead, for mask-worn faces, the perceived attractiveness ratings for baseline unattractive faces were higher.

This change in the perceived attractiveness of mask-worn faces can be explained by the reduced association between unhealthiness and sanitary masks. This reduction was supported by the results of Study 3, that is, that mask-worn faces were perceived as healthier after the onset of the COVID-19 epidemic compared with before the epidemic. Mask-worn faces were perceived as less healthy than no-mask faces regardless of the measurement period (before or after the onset of the epidemic). However, our data indicate that the association between mask-wearing and unhealthiness had weakened. We suggest that this reduction in the strength of the association was caused by the change of the purpose of mask use. Specifically, before the COVID-19 epidemic, masks were associated with personal medical problems experienced by the wearer, such as symptoms of illness (e.g., coughing or rhinorrhea) or allergies to pollen. After the onset of the epidemic, masks became associated with society-wide attempts to prevent the spread of COVID-19 infection and have become a social norm such that seeing mask-worn people may encourage an individual to wear a mask (Nakayachi et al., 2020).

Our results were consistent with the two-factor model of the sanitary-mask effect. Miyazaki and Kawahara (2016) provided converging evidence to support the model, which was proposed before the COVID-19 epidemic. Furthermore, prior to the onset of the epidemic, they predicted that removing the perception of unhealthiness associated with mask-wearing would reduce the negative impact on attractiveness ratings. To examine this possibility, they replaced a mask with a notebook and found that the results supported their prediction. They replicated this finding by replacing a mask with a card that occluded the same lower area of the face. The pattern they observed was similar to our finding in Study 2, which was consistent with the two-factor model.

Our data, along with those of previous studies, indicate that the mechanism underlying the modulation of attractiveness by mask-wearing is related to the occlusion of critical features. Occluding less attractive faces can hide negative features, such as asymmetric contours, imbalanced arrangements of facial features, and pimples. This could shift attractiveness ratings toward the average, and thus improve ratings for baseline unattractive faces. The opposite is true for attractive faces. Occluding attractive faces can hide positive features, such as symmetric contours, balanced arrangements of features, and smooth skin. This could shift attractiveness ratings toward the average, thus reducing ratings for baseline attractive faces. These ideas were supported by the findings of Study 2. Because the association between unhealthiness and mask-wearing had weakened after the onset of the COVID-19 epidemic, the effects of masks on ratings of perceived unhealthiness were similar to those of the notebooks and cards used to occlude faces in Miyazaki and Kawahara’s (2016; Experiments 3a, 3b, and 4) occlusion experiments. This mechanism may be related to recent findings that perceived facial attractiveness ratings improved when faces were partially occluded by vertical occluders or randomly scattered dots (Orghian & Hidalgo, 2020).

This study revealed the impact of a social incident, that is, the COVID-19 epidemic, on perceptions of attractiveness of mask-worn faces. Given that larger attitude shifts regarding support for politicians concerned about climate change were found in individuals who reported greater suffering from hurricanes (Rudman et al., 2013), our finding that beliefs and perceptions regarding the attractiveness and healthiness of mask-worn faces had already changed just months after the explicit onset of the COVID-19 epidemic in Japan (the first patient was found on January 16) implies that the magnitude of the impact is large. Accordingly, we expect that modulation of the sanitary-mask effect directly reflects the progress of the epidemic. In other words, this study demonstrated a contextual modulation of facial perception that took place over a short period of time. However, given that the context in which individuals view target faces can modulate facial attractiveness in a laboratory setting (e.g., varying the proportion of beard-worn vs. clean-shaven faces; Janif et al., 2014), the modulation observed in this study may change with the severity of the epidemic. Long-term measurements of beliefs and perceptions regarding mask-worn faces would provide more information regarding the impact of the epidemic on societies worldwide.

There are two limitations to this study. First, the three-way Period × Baseline attractiveness × Mask presence interaction was not significant, probably due to differences in the baseline conditions of the previous (Miyazaki & Kawahara, 2016) and present studies, although the trend indicated by the results was consistent with the predicted direction. Therefore, the impact of the COVID-19 epidemic on perceived attractiveness warrants careful interpretation and further examination. Second, the change in the purpose of mask use might have introduced a demand bias effect such that participants might have avoided saying that they found a given mask-wearing woman unattractive due to the social norms governing mask-wearing. The demand bias may explain the results for faces with low attractiveness scores, but this explanation is not applicable to faces with high attractiveness scores. Therefore, we believe that the present results cannot be solely attributed to demand bias. Nonetheless, this is a limitation of this study, although it was unavoidable.

Blatant sexual deception: No gender differences in overall rates of deception, though men were more deceptive regarding wealth and resources, occupation, and physical characteristics than women

Blatant sexual deception: Content, individual differences, and implications. Flora Oswald, Devinder Khera, Kari A. Walton, Cory L. Pedersen. Personality and Individual Differences, Volume 183, December 2021, 111118.

Abstract: Given current cultural attention to issues surrounding sexual consent, the issue of sexual deception is pertinent. The current study examined rates of different forms of blatant sexual deception (i.e., intentionally misleading sexual partners) with a focus on individual predictors including demographic correlates and traits of narcissism and sexual compulsivity. We sought to extend existing literature on sexual deception by examining novel forms of deception in a gender- and sexual orientation- diverse sample. Participants (N = 1769) aged 16 to 81 years (M = 26.60) took part in an online study. Results showed no gender differences in overall rates of deception, though men were more deceptive regarding wealth and resources, occupation, and physical characteristics than women. Sexual minorities reported higher rates of sexual deception than heterosexual participants pertaining to sexual orientation and previous partner gender. Participant scores on sexual narcissism and sexual compulsivity were significantly correlated with sexual deception scores. Findings are discussed in relation to how sexual deception can be understood and potentially intervened upon within current cultures of consent.

Keywords: NarcissismSexual compulsivityGenderSexual orientation

We report the first observation of a chimpanzee with albinism in the wild, describe interactions between the infant & other group members, & describe the subsequent infanticide of the individual with albinism by his conspecifics

First observation of a chimpanzee with albinism in the wild: Social interactions and subsequent infanticide. Maël Leroux, Gideon Monday, Bosco Chandia, John W. Akankwasa, Klaus Zuberbühler, Catherine Hobaiter, Catherine Crockford, Simon W. Townsend, Caroline Asiimwe, Pawel Fedurek. American Journal of Primatology, July 16 2021.

Research Highlights

Observations of wild non-human primates with albinism are extremely rare

We report the first observation of a chimpanzee with albinism in the wild

We describe interactions between the infant with albinism and other group members

We describe the subsequent infanticide of the individual with albinism

We discuss these observations in light of our understanding of chimpanzee behavior

Abstract: Albinism—the congenital absence of pigmentation—is a very rare phenomenon in animals due to the significant costs to fitness of this condition. Both humans and non-human individuals with albinism face a number of challenges, such as reduced vision, increased exposure to ultraviolet radiation, or compromised crypticity resulting in an elevated vulnerability to predation. However, while observations of social interactions involving individuals with albinism have been observed in wild non-primate animals, such interactions have not been described in detail in non-human primates (hereafter, primates). Here, we report, to our knowledge, the first sighting of an infant with albinism in wild chimpanzees (Pan troglodytes schweinfurthii), including social interactions between the infant, its mother, and group members. We also describe the subsequent killing of the infant by conspecifics as well as their behavior towards the corpse following the infanticide. Finally, we discuss our observations in relation to our understanding of chimpanzee behavior or attitudes towards individuals with very conspicuous appearances.


We describe here, to our knowledge, the first observation of a chimpanzee with albinism in a wild ape population. Importantly, we provide a unique account of interactions between the community members and the infant with albinism (and its mother) upon initial encounter and during the day of the infanticide.

The initial reaction of community members towards the infant appeared to be different from a typical situation in which chimpanzees encounter females with a newborn for the first time. Community members of both sexes often show signs of curiosity towards a newborn upon first sighting, such as grooming the mother or looking attentively at the newborn, touching, or grooming it (Goodall, 1986; Gideon Monday and Pawel Fedurek, personal observation). While individuals can respond to such events with excitement or aggression, particularly in the study community where infanticides are common (Lowe et al., 2019), interactions which included apparent fear towards a newborn are unusual and have not been observed to the same extent as seen on this occasion.

Although it is not possible to draw firm conclusions from this one observation, it appears that the encounter with the infant with albinism had an arousing effect on most adult community members. For example, even though some individuals responded calmly to the infant, most adult individuals seemed to react with fear upon encountering the newborn by keeping distance and producing alarm hoos and waa barks. In chimpanzees, these two call types are associated with risky, and potentially deadly situations, such as encountering snakes, bush pigs, or unfamiliar humans (Crockford et al., 2017; Goodall, 1986; Schel et al., 2013). Notably, this initial, apparently fearful, behavior was followed by physical aggression towards the infant and eventually death. In this respect, our observation shares similarities to those recorded in some bird species, where agonistic behaviors towards individuals with albinism were observed (Roberts, 1978).

The captive infant female chimpanzee Pinkie, the only other known chimpanzee with albinism, was captured alive in the wild as a newborn. However, it is not possible to establish how the original community members had reacted to, or interacted with, her before her capture (or whether they had seen her in the first place) as no such records before the capture exist. Similarly, the account of the successful introduction of Pinkie to a group of captive chimpanzees has not been published, which makes it difficult to establish whether and how an introduction of an infant with albinism to a group of stranger chimpanzees differs from an introduction of an in-group chimpanzee infant. We consider, therefore, our descriptive account of interactions of several conspecifics with an individual with albinism from the same wild community as unique.

The Sonso community has a history of infanticide committed by both adult males (Newton-Fisher, 1999) and, more rarely, females (Lowe et al., 2019; Townsend et al., 2007), which includes frequent within-community killings (Lowe et al., 2019). It is, therefore, possible that the infant with albinism would have become a victim of infanticide regardless of its appearance. The way the body was mutilated did not differ considerably from the way bodies of chimpanzee victims of within-community killings are often afflicted (Lowe et al., 2019; Wilson et al., 2014). For example, fingers of the right hand were bitten off, so was (partially) the left foot (see Supporting Information Material 3). However, the magnitude of the reaction some of the community members exhibited towards the infant with albinism makes it likely that the infant was not considered as a typical chimpanzee. The vigilant and even fearful behavior including alarm calling by individuals upon the initial exposure to the infant seems to support this idea.

Similarly, the careful and repeated inspection of the carcass by several individuals ranging from infants to adults of both sexes does not seem to be a typical behavior that chimpanzees direct towards a dead infant. Indeed, in contrast to our observation, most studies report that mainly the mother, and sometimes kin, initiate extended contact with a dead infant, sometimes displaying affiliative behaviors towards it, such as grooming (Biro et al., 2010; Cronin et al., 2011; Lonsdorf et al., 2020). Furthermore, in our study, one adult male was seen using his lips to pinch the hair of the dead infant, and several other individuals were seen stroking the hair of the carcass. Such behaviors have not been reported before in the context of infanticide in the Sonso community (Lowe et al., 2019; Catherine Crockford, personal observation), and could have been elicited by the unusual pigmentation of the infant. Indeed, the behavior of the chimpanzees towards the corpse of the infant with albinism resembles that of chimpanzees when presented with a novel object: Chimpanzees usually engage with such objects with initial caution followed by examining it carefully and touching it (Russell et al., 1997). However, some of the behaviors of group members towards the carcass of the infant with albinism, such as grooming it—a behavior previously described in this context in non-human primates including chimpanzees (Gonçalves & Carvalho, 2019), clearly indicate that the infant was not perceived by them as an object, but as a conspecific of an unusual appearance. However, since observations of chimpanzees interacting with individuals of atypical appearance are very rare, more data of this kind are needed to explore the cognitive mechanisms behind this behavior. Likewise, although our unique observations are potentially relevant to the understanding of chimpanzee death perception (e.g., Gonçalves & Carvalho, 2019), more data of this kind are needed to investigate the cognitive processes underlying it.

The inspection of the carcass by individuals often focused on the anogenital regions, with several individuals inserting their fingers into the anus of the carcass. To our knowledge, only one observation of this kind has been made in chimpanzees before: An adult female inserting a digit in the anus of the former alpha male dead body (Pruetz et al., 2017). In our study, both adult and infant males were seen inserting a digit in the anus of the infant with albinism. Several mammal species possess anal glands that play a role in olfactory communication. For example, anal gland secretion conveys information about kinship in beavers (Castor canadensis) (Sun & Müller-Schwarze, 1998) and lemurs (Lemur catta) (Charpentier et al., 2010). In spotted hyenas (Crocuta crocuta), individuals discriminate identity and social status of a conspecific through anal gland scent (Burgener et al., 2009), whereas black rhinoceros (Diceros bicornis) can differentiate sex and age using gland scent (Linklater et al., 2013). Chimpanzees also use olfactory communication when identifying the recent presence of individuals from other communities in their territory (Henkel & Setchell, 2018). Furthermore, another study on chimpanzees reported an observation of the mother and another adult female bringing their hands towards their face after touching a dead infant as if to gain information about its body (Cronin et al., 2011). Our observation potentially indicates that olfactory cues were used to gain information about the infant with albinism because, for example, it was not perceived by conspecifics as a typical individual or an individual from their own territory.

Although in some species individuals with albinism tend to have smaller body sizes (Slagsvold et al., 1988), the size of the infant in this study was normal considering its estimated 3 weeks of age. Autopsy results did not reveal any apparent major health issues and, during the initial encounter, the infant appeared to behave normally. Thus, we have no observations that suggest that the peculiar behavior of the chimpanzees towards the infant, or its carcass, were driven by any potential morphological abnormalities of the body except its coloration. It is important to note, however, that histopathology tests on the carcass were not conducted, and therefore, we do not have detailed information about the infant's health. The white coloration of the infant bears similarities to that of black and white colobus monkey (Colobus guereza) infants that Budongo chimpanzees often prey on (Reynolds, 2005). Therefore, another intriguing possibility is that the infant's pattern of coloration matched features of this community “prey image” (Uehara, 1997), but with the form and odor of a chimpanzee and this incongruence could explain the behavior of some of the individuals towards the infant.

To conclude, we provide a unique account of behaviors of wild chimpanzees towards an infant with albinism before and following its death. Our observations provide insights into chimpanzee behavior in extremely rare social circumstances.