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Alexander Weiss - One of the best experts on this subject based on the ideXlab platform.
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A comparison of Personality in the common and Bolivian squirrel monkey (Saimiri sciureus and Saimiri boliviensis).
Journal of Comparative Psychology, 2018Co-Authors: Vanessa A. D. Wilson, Miho Inoue-murayama, Alexander WeissAbstract:Personality has been studied in all of the great apes, many Old World monkey species, but only a handful of New World monkey species. Because understanding the personalities of New World monkeys is crucial to understanding Personality evolution in primates, we used the Hominoid Personality Questionnaire to assess Personality in 55 common squirrel monkeys (Saimiri sciureus) and 40 Bolivian squirrel monkeys (Saimiri boliviensis). We found 4 Personality components in each species, and labeled them Openness, Neuroticism, Assertiveness, and Agreeableness. We then, in a genus-level analysis, found 5 components, which we labeled Neuroticism, Openness, Assertiveness, Agreeableness, and Decisiveness. Comparisons of the genus- and species-level Structures revealed that common squirrel monkeys had a Personality Structure that more closely resembled the genus-level Structure than did Bolivian squirrel monkeys. We then compared the Personality Structures of common and Bolivian squirrel monkeys with that of brown capuchin monkeys, Sapajus apella. The Personality Structure of Bolivian squirrel monkeys more closely resembled that of brown capuchins. These findings suggest that the Bolivian squirrel monkey Personality Structure is ancestral and that Assertiveness and Openness are ancestral to both the Saimiri genus and brown capuchins; Agreeableness and Neuroticism seem to be derived in Saimiri. We discuss these findings in relation to differences in the social Structures and ecologies of these species. (PsycINFO Database Record
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common marmoset callithrix jacchus Personality
Journal of Comparative Psychology, 2017Co-Authors: Sonja E Koski, Hannah M Buchanansmith, Hayley Ash, Judith M Burkart, Thomas Bugnyar, Alexander WeissAbstract:Increasing evidence suggests that Personality Structure differs between species, but the evolutionary reasons for this variation are not fully understood. We built on earlier research on New World monkeys to further elucidate the evolution of Personality Structure in primates. We therefore examined Personality in 100 family-reared adult common marmosets (Callithrix jacchus) from 3 colonies on a 60-item questionnaire. Principal components analyses revealed 5 domains that were largely similar to those found in a previous study on captive, ex-pet, or formerly laboratory-housed marmosets that were housed in a sanctuary. The interrater reliabilities of domain scores were consistent with the interrater reliabilities of domain scores found in other species, including humans. Four domainsdmdash;conscientiousness, agreeableness, inquisitiveness, and assertiveness-resembled Personality domains identified in other nonhuman primates. The remaining domain, patience, was specific to common marmosets. We used linear models to test for sex and age differences in the Personality domains. Males were lower than females in patience, and this difference was smaller in older marmosets. Older marmosets were lower in inquisitiveness. Finally, older males and younger females had higher scores in agreeableness than younger males and older females. These findings suggest that cooperative breeding may have promoted the evolution of social cognition and influenced the Structure of marmoset prosocial Personality characteristics. (PsycINFO Database Record
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divergent Personality Structures of brown sapajus apella and white faced capuchins cebus capucinus
Journal of Comparative Psychology, 2016Co-Authors: Lauren M. Robinson, Annika Paukner, Sarah F. Brosnan, Blake F Morton, Jane Widness, Jennifer L Essler, Marieke Cassia Gartner, Alexander WeissAbstract:: One way to gain insights into Personality evolution is by comparing the Personality Structures of related species. We compared the Personality Structure of 240 wild white-faced capuchin monkeys to the Personality Structure of 100 captive brown capuchin monkeys. An ancillary goal was to test the degree to which different Personality questionnaires yielded similar Personality dimensions. Both species were rated on a common set of 26 antonym pairs. The brown capuchin monkeys were also rated on the 54-item Hominoid Personality Questionnaire. Our cross-species comparisons revealed 3 Personality dimensions-Assertiveness, Openness, and Neuroticism-shared by brown and white-faced capuchins, suggesting that these dimensions were present in the common ancestor of these species. Our comparison of the dimensions derived from the antonym pairs and the Hominoid Personality Questionnaire revealed that three common dimensions were identified by both questionnaires. In addition, the dimension Attentiveness was only identified using the Hominoid Personality Questionnaire. These results indicate that major features of capuchin Personality are conserved and that the Structure of some traits, such as those related to focus, persistence, and attention, diverged. Further work is needed to identify the evolutionary bases that led to the conservation of some dimensions but not others. (PsycINFO Database Record
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Personality Structure and social style in macaques
Journal of Personality and Social Psychology, 2015Co-Authors: Mark J Adams, Bernard Thierry, Anja Widdig, Antje Engelhardt, Bonaventura Majolo, Julia Ostner, Oliver Schulke, Arianna De Marco, Melissa S Gerald, Alexander WeissAbstract:Why regularities in Personality can be described with particular dimensions is a basic question in differential psychology. Nonhuman primates can also be characterized in terms of Personality Structure. Comparative approaches can help reveal phylogenetic constraints and social and ecological patterns associated with the presence or absence of specific Personality dimensions. We sought to determine how different Personality Structures are related to interspecific variation in social style. Specifically, we examined this question in 6 different species of macaques, because macaque social style is well characterized and can be categorized on a spectrum of despotic (Grade 1) versus tolerant (Grade 4) social styles. We derived Personality Structures from adjectival ratings of Japanese (Macaca fuscata; Grade 1), Assamese (M. assamensis; Grade 2), Barbary (M. sylvanus; Grade 3), Tonkean (M. tonkeana; Grade 4), and crested (M. nigra; Grade 4) macaques and compared these species with rhesus macaques (M. mulatta; Grade 1) whose Personality was previously characterized. Using a nonparametric method, fuzzy set analysis, to identify commonalities in Personality dimensions across species, we found that all but 1 species exhibited consistently defined Friendliness and Openness dimensions, but that similarities in Personality dimensions capturing aggression and social competence reflect similarities in social styles. These findings suggest that social and phylogenetic relationships contribute to the origin, maintenance, and diversification of Personality.
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Personality Structure in the domestic cat felis silvestris catus scottish wildcat felis silvestris grampia clouded leopard neofelis nebulosa snow leopard panthera uncia and african lion panthera leo a comparative study
Journal of Comparative Psychology, 2014Co-Authors: Marieke Cassia Gartner, David M Powell, Alexander WeissAbstract:: Although the study of nonhuman Personality has increased in the last decade, there are still few studies on felid species, and the majority focus on domestic cats. We assessed the Structure of Personality and its reliability in five felids-domestic cats, clouded leopards, snow leopards, African lions, and previous data on Scottish wildcats-and compared the results. In addition to the benefits of understanding more about this taxon, comparative studies of Personality Structure have the potential to provide information on evolutionary relationships among closely related species. Each of the species studied was found to have three factors of Personality. Scottish wildcats' factors were labeled Dominance, Agreeableness, and Self Control; domestic cats' factors were Dominance, Impulsiveness, and Neuroticism; clouded leopards' factors were Dominance/Impulsiveness, Agreeableness/Openness, and Neuroticism; snow leopards' factors were Dominance, Impulsiveness/Openness, and Neuroticism; and African lions' factors were Dominance, Impulsiveness, and Neuroticism. The Neuroticism and Impulsiveness factors were similar, as were two of the Dominance factors. A taxon-level Personality Structure also showed three similar factors. Age and sex effects are also discussed.
Michael C Ashton - One of the best experts on this subject based on the ideXlab platform.
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objections to the hexaco model of Personality Structure and why those objections fail
European Journal of Personality, 2020Co-Authors: Michael C Ashton, Kibeom LeeAbstract:The six–dimensional HEXACO model of Personality Structure and its associated inventory have increasingly been used in Personality research. But in spite of the evidence supporting this Structure an...
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are dishonest extraverts more harmful than dishonest introverts the interaction effects of honesty humility and extraversion in predicting workplace deviance
2011Co-Authors: Kibeom Lee, Michael C Ashton, Reinout E De VriesAbstract:Honesty-Humility, one of the six major Personality dimensions included in the HEXACO model of Personality Structure, has previously been found to show negative correlations with workplace deviance. In this study, we hypothesized that Extraversion would moderate the relationship between Honesty-Humility and workplace deviance. In particular, we posited that the relation between Honesty-Humility and workplace deviance would be stronger among employees who are high on Extraversion than among those low on Extraversion. The hypothesis was tested using three different samples across Australia, Canada, and the Netherlands. It was found in two of the three samples that high levels of Extraversion did indeed amplify the relationship between (low) Honesty-Humility and workplace deviance. Results suggest a potentially important role for multiplicative effects of Personality variables on workplace criteria.
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the hexaco model of Personality Structure and the importance of the h factor
Social and Personality Psychology Compass, 2008Co-Authors: Michael C Ashton, Kibeom LeeAbstract:We give a brief summary of recent research on the Structure of Personality characteristics, describing the six-dimensional ‘HEXACO’ model that has emerged as the most accurate representation of that Structure. We then discuss the importance of Personality as a predictor of socially important criteria, describing a variety of examples involving the Honesty–Humility (H) factor. The H dimension, alone or in combination with other factors of the HEXACO model, is related inversely to a wide array of criteria, including criminal activity and other unethical behaviors as well as materialistic and power-seeking tendencies.
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empirical theoretical and practical advantages of the hexaco model of Personality Structure
Personality and Social Psychology Review, 2007Co-Authors: Michael C AshtonAbstract:The authors argue that a new six-dimensional framework for Personality Structure—the HEXACO model— constitutes a viable alternative to the well-known Big Five or five-factor model. The new model is consistent with the cross-culturally replicated finding of a common six-dimensional Structure containing the factors Honesty-Humility (H), Emotionality (E), eExtraversion (X), Agreeableness (A), Conscientiousness (C), and Openness to Experience (O). Also, the HEXACO model predicts several Personality phenomena that are not explained within the B5/FFM, including the relations of Personality factors with theoretical biologists' constructs of reciprocal and kin altruism and the patterns of sex differences in Personality traits. In addition, the HEXACO model accommodates several Personality variables that are poorly assimilated within the B5/FFM.
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the hexaco model of Personality Structure and indigenous lexical Personality dimensions in italian dutch and english
Journal of Research in Personality, 2006Co-Authors: Michael C Ashton, Reinout E De Vries, Kibeom Lee, Marco Perugini, Augusto Gnisci, Ida SergiAbstract:We correlated the scales of the HEXACO Personality Inventory (HEXACO-PI) with adjective scale markers of Personality factors previously obtained in indigenous lexical studies of Personality Structure in the Italian, Dutch, and English languages. Self-ratings were obtained from samples of 327 Italian, 161 Dutch, and 214 English-speaking Canadian participants. Results showed that each of the six HEXACO variables—including Honesty–Humility—correlated strongly with its hypothesized six-factor adjective scale counterpart in all three languages. In each case, convergent correlations were substantially stronger than discriminant correlations. Because the HEXACO model was developed without prior knowledge of the indigenous Dutch and English lexical factors, the results suggest that the HEXACO model of Personality Structure can be extended to the Personality lexicons of those languages.
Kibeom Lee - One of the best experts on this subject based on the ideXlab platform.
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objections to the hexaco model of Personality Structure and why those objections fail
European Journal of Personality, 2020Co-Authors: Michael C Ashton, Kibeom LeeAbstract:The six–dimensional HEXACO model of Personality Structure and its associated inventory have increasingly been used in Personality research. But in spite of the evidence supporting this Structure an...
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are dishonest extraverts more harmful than dishonest introverts the interaction effects of honesty humility and extraversion in predicting workplace deviance
2011Co-Authors: Kibeom Lee, Michael C Ashton, Reinout E De VriesAbstract:Honesty-Humility, one of the six major Personality dimensions included in the HEXACO model of Personality Structure, has previously been found to show negative correlations with workplace deviance. In this study, we hypothesized that Extraversion would moderate the relationship between Honesty-Humility and workplace deviance. In particular, we posited that the relation between Honesty-Humility and workplace deviance would be stronger among employees who are high on Extraversion than among those low on Extraversion. The hypothesis was tested using three different samples across Australia, Canada, and the Netherlands. It was found in two of the three samples that high levels of Extraversion did indeed amplify the relationship between (low) Honesty-Humility and workplace deviance. Results suggest a potentially important role for multiplicative effects of Personality variables on workplace criteria.
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the hexaco model of Personality Structure and the importance of the h factor
Social and Personality Psychology Compass, 2008Co-Authors: Michael C Ashton, Kibeom LeeAbstract:We give a brief summary of recent research on the Structure of Personality characteristics, describing the six-dimensional ‘HEXACO’ model that has emerged as the most accurate representation of that Structure. We then discuss the importance of Personality as a predictor of socially important criteria, describing a variety of examples involving the Honesty–Humility (H) factor. The H dimension, alone or in combination with other factors of the HEXACO model, is related inversely to a wide array of criteria, including criminal activity and other unethical behaviors as well as materialistic and power-seeking tendencies.
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the hexaco model of Personality Structure and indigenous lexical Personality dimensions in italian dutch and english
Journal of Research in Personality, 2006Co-Authors: Michael C Ashton, Reinout E De Vries, Kibeom Lee, Marco Perugini, Augusto Gnisci, Ida SergiAbstract:We correlated the scales of the HEXACO Personality Inventory (HEXACO-PI) with adjective scale markers of Personality factors previously obtained in indigenous lexical studies of Personality Structure in the Italian, Dutch, and English languages. Self-ratings were obtained from samples of 327 Italian, 161 Dutch, and 214 English-speaking Canadian participants. Results showed that each of the six HEXACO variables—including Honesty–Humility—correlated strongly with its hypothesized six-factor adjective scale counterpart in all three languages. In each case, convergent correlations were substantially stronger than discriminant correlations. Because the HEXACO model was developed without prior knowledge of the indigenous Dutch and English lexical factors, the results suggest that the HEXACO model of Personality Structure can be extended to the Personality lexicons of those languages.
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further assessment of the hexaco Personality inventory two new facet scales and an observer report form
Psychological Assessment, 2006Co-Authors: Kibeom Lee, Michael C AshtonAbstract:The HEXACO Personality Inventory (HEXACO-PI) operationalizes the six factors obtained from lexical studies of Personality Structure in several languages. In this study, psychometric properties of the HEXACO-PI were assessed using a community adult sample and also using observer reports, thereby extending the previous investigation relying only on self-reports from a college student sample. In addition to examining the original 24 HEXACO-PI facet scales, the authors also examined two new facet scales--Altruism versus Antagonism and Negative Self-Evaluation--that assess constructs located interstitially among the factors of the HEXACO space. The HEXACO-PI again showed favorable psychometric properties in terms of reliability and factor Structure and also showed high levels of self/observer agreement.
Blake F Morton - One of the best experts on this subject based on the ideXlab platform.
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divergent Personality Structures of brown sapajus apella and white faced capuchins cebus capucinus
Journal of Comparative Psychology, 2016Co-Authors: Lauren M. Robinson, Annika Paukner, Sarah F. Brosnan, Blake F Morton, Jane Widness, Jennifer L Essler, Marieke Cassia Gartner, Alexander WeissAbstract:: One way to gain insights into Personality evolution is by comparing the Personality Structures of related species. We compared the Personality Structure of 240 wild white-faced capuchin monkeys to the Personality Structure of 100 captive brown capuchin monkeys. An ancillary goal was to test the degree to which different Personality questionnaires yielded similar Personality dimensions. Both species were rated on a common set of 26 antonym pairs. The brown capuchin monkeys were also rated on the 54-item Hominoid Personality Questionnaire. Our cross-species comparisons revealed 3 Personality dimensions-Assertiveness, Openness, and Neuroticism-shared by brown and white-faced capuchins, suggesting that these dimensions were present in the common ancestor of these species. Our comparison of the dimensions derived from the antonym pairs and the Hominoid Personality Questionnaire revealed that three common dimensions were identified by both questionnaires. In addition, the dimension Attentiveness was only identified using the Hominoid Personality Questionnaire. These results indicate that major features of capuchin Personality are conserved and that the Structure of some traits, such as those related to focus, persistence, and attention, diverged. Further work is needed to identify the evolutionary bases that led to the conservation of some dimensions but not others. (PsycINFO Database Record
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Personality Structure in brown capuchin monkeys sapajus apella comparisons with chimpanzees pan troglodytes orangutans pongo spp and rhesus macaques macaca mulatta
Journal of Comparative Psychology, 2013Co-Authors: Blake F Morton, Bernard Thierry, Annika Paukner, Frans B. M. De Waal, Sarah F. Brosnan, Hannah M Buchanansmith, Jane Widness, Jennifer L Essler, Alexander WeissAbstract:Personality, defined here as consistent individual differences in behavior (Carere & Eens, 2005), has been studied in many animals, including mammals, birds, fish, reptiles, amphibians, and invertebrates (Gosling, 2001). Personality in nonhuman species has sometimes been labeled as “noise” deviating from behavioral norms. However, research shows that such traits are heritable (Adams, King, & Weiss, 2012; van Oers, de Jong, van Noordwijk, Kempenaers, & Drent, 2005), stable over time and across contexts (Bell, Hankison, & Laskowski, 2009; Capitanio, 1999; Stevenson-Hinde, Stillwell-Barnes, & Zunz, 1980; Uher, Asendorpf, & Call, 2008; Weiss, Adams, Widdig, & Gerald, 2011), and predict life history patterns (e.g., metabolic rate, reproduction, health, and longevity; Capitanio, 2011; Careau, Bininda-Emonds, Thomas, Reale, & Humphries, 2009; Cavigelli, Bennett, Michael, & Klein, 2008; Reale, Martin, Coltman, Poissant, & Festa-Bianchet, 2009; Weiss, Gartner, Gold, & Stoinski, 2012). Personality traits (e.g. curious, fearful, and aggressive) tend to cluster into one or more broader dimensions. An individual’s score on a given dimension corresponds to their position along a particular behavioral continuum (e.g., the shy-bold axis; Wilson, Clark, Coleman, & Dearstyne, 1994). When assessed using standardized methods, comparisons of Personality Structure across species may help researchers address questions about the phylogeny and evolution of Personality (Gosling & Graybeal, 2007). In the case of nonhuman primates (hereafter ‘primates’), King and Figueredo (1997) reported that chimpanzee (Pan troglodytes) Personality is comprised of a species-specific dimension, Dominance, and five dimensions similar to those found in many human Personality studies – Extraversion, Conscientiousness, Agreeableness, Neuroticism, and Openness (e.g., Digman, 1990; Eysenck, 1970; Lee, Ogunfowora, & Ashton, 2005). A study of orangutans (Pongo spp.) using the same scale found dimensions resembling chimpanzee Neuroticism, Extraversion, Agreeableness, and Dominance (Weiss, King, & Perkins, 2006). However, instead of the distinct Conscientiousness and Openness dimensions found in chimpanzees, orangutans have a dimension, Intellect, comprised of traits associated with both. More recently, a study of rhesus macaques (Macaca mulatta) using a comparable instrument found dimensions similar to chimpanzee Openness and chimpanzee/orangutan Dominance (Weiss, et al., 2011). However, unlike chimpanzees and orangutans, rhesus macaques do not have dimensions resembling Extraversion or Neuroticism; rather, traits shared with these dimensions are classified under dimensions labeled Activity (e.g. innovative and playful), Friendliness (e.g. affectionate, sociable, sensitive), Confidence (e.g. stable, dominant, cool), and Anxiety (e.g. impulsive, anxious, erratic). These findings suggest that some Personality dimensions may be phylogenetically old and shared across species (e.g. Dominance-like dimensions), while others may have evolved more recently (e.g. Conscientiousness and Intellect). To date, research on Personality has predominantly been limited to catarrhines, that is apes, including humans, and Old World monkeys (Freeman & Gosling 2010). Platyrrhines (New World monkeys) are only distantly related to catarrhine species, sharing a common ancestor about 43 million years ago (Steiper & Young, 2006). However, some New World species exhibit behavioral and cognitive similarities to catarrhine species, particularly capuchin monkeys (Cebus and Sapajus spp.) and spider monkeys (Ateles spp.) (Amici, Aureli, & Call, 2008; Deaner, van Schaik, & Johnson, 2006; Fragaszy, Visalberghi, & Fedigan, 2004). Thus, comparative studies of Personality in Old and New World species may help identify variables within the natural and social world of primates that contribute to Personality evolution. In this study, we examined Personality Structure in a New World primate, the brown capuchin monkey (Sapajus apella, formerly Cebus apella; Alfaro, Silva, & Rylands, 2012). We first derived Personality Structure in brown capuchins using observer ratings, and examined its association with systematically recorded behaviors. We then compared Personality Structure in brown capuchins to those reported in chimpanzees, orangutans, and rhesus macaques – all of which were rated using the same or similar scale. Ratings of brown capuchin monkeys on individual Personality traits have been associated with cortisol reactivity (Byrne & Suomi, 2002). Thus, human observer ratings capture biologically-meaningful information about this taxon. However, it is unknown how individual traits cluster into Personality dimensions in brown capuchins, and how the Structure of these dimensions compares to those of other primates. Our study was conducted contemporaneously with another study which derived Personality Structure in white-faced capuchins (Cebus capucinus; Manson & Perry, in press). Brown capuchins, chimpanzees, and orangutans have large brains relative to their body size, are extractive foragers, are very tolerant of non-kin, rely on social learning, and have “cultural” traditions (Fragaszy, Visalberghi, & Fedigan, 2004). Moreover, brown capuchins exhibit delayed gratification tolerances more like those of great apes than more closely related platyrrhines such as marmosets (Callithrix jacchus) and tamarins (Saguinus oedipus) (Addessi, Paglieri, & Focaroli, 2011). Unlike semi-solitary orangutans (Rodman, 1984), however, capuchins and chimpanzees are considerably more social and have many of the same basic properties of sociality as other group-living primates, including rhesus macaques. For example, they live in multimale-multifemale groups, have social hierarchies, provide coalitionary support to others, display post-conflict reconciliations, and frequently engage in social grooming (Fragaszy, et al., 2004; Maestripieri & Hoffman, 2012; Stanford, 1998). Thus, collectively, the behavior and cognitive traits of brown capuchins are qualitatively more like those of chimpanzees than other primate species. Individual differences in behavioral and cognitive traits are closely associated with differences in Personality (reviewed in Carere & Locurto, 2011). Thus, given the behavioral and cognitive similarities between brown capuchins and great apes, we hypothesized that the Personality Structure of brown capuchins would overlap more with great apes – and in particular, chimpanzees – than with rhesus macaques.
Annika Paukner - One of the best experts on this subject based on the ideXlab platform.
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divergent Personality Structures of brown sapajus apella and white faced capuchins cebus capucinus
Journal of Comparative Psychology, 2016Co-Authors: Lauren M. Robinson, Annika Paukner, Sarah F. Brosnan, Blake F Morton, Jane Widness, Jennifer L Essler, Marieke Cassia Gartner, Alexander WeissAbstract:: One way to gain insights into Personality evolution is by comparing the Personality Structures of related species. We compared the Personality Structure of 240 wild white-faced capuchin monkeys to the Personality Structure of 100 captive brown capuchin monkeys. An ancillary goal was to test the degree to which different Personality questionnaires yielded similar Personality dimensions. Both species were rated on a common set of 26 antonym pairs. The brown capuchin monkeys were also rated on the 54-item Hominoid Personality Questionnaire. Our cross-species comparisons revealed 3 Personality dimensions-Assertiveness, Openness, and Neuroticism-shared by brown and white-faced capuchins, suggesting that these dimensions were present in the common ancestor of these species. Our comparison of the dimensions derived from the antonym pairs and the Hominoid Personality Questionnaire revealed that three common dimensions were identified by both questionnaires. In addition, the dimension Attentiveness was only identified using the Hominoid Personality Questionnaire. These results indicate that major features of capuchin Personality are conserved and that the Structure of some traits, such as those related to focus, persistence, and attention, diverged. Further work is needed to identify the evolutionary bases that led to the conservation of some dimensions but not others. (PsycINFO Database Record
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Personality Structure in brown capuchin monkeys sapajus apella comparisons with chimpanzees pan troglodytes orangutans pongo spp and rhesus macaques macaca mulatta
Journal of Comparative Psychology, 2013Co-Authors: Blake F Morton, Bernard Thierry, Annika Paukner, Frans B. M. De Waal, Sarah F. Brosnan, Hannah M Buchanansmith, Jane Widness, Jennifer L Essler, Alexander WeissAbstract:Personality, defined here as consistent individual differences in behavior (Carere & Eens, 2005), has been studied in many animals, including mammals, birds, fish, reptiles, amphibians, and invertebrates (Gosling, 2001). Personality in nonhuman species has sometimes been labeled as “noise” deviating from behavioral norms. However, research shows that such traits are heritable (Adams, King, & Weiss, 2012; van Oers, de Jong, van Noordwijk, Kempenaers, & Drent, 2005), stable over time and across contexts (Bell, Hankison, & Laskowski, 2009; Capitanio, 1999; Stevenson-Hinde, Stillwell-Barnes, & Zunz, 1980; Uher, Asendorpf, & Call, 2008; Weiss, Adams, Widdig, & Gerald, 2011), and predict life history patterns (e.g., metabolic rate, reproduction, health, and longevity; Capitanio, 2011; Careau, Bininda-Emonds, Thomas, Reale, & Humphries, 2009; Cavigelli, Bennett, Michael, & Klein, 2008; Reale, Martin, Coltman, Poissant, & Festa-Bianchet, 2009; Weiss, Gartner, Gold, & Stoinski, 2012). Personality traits (e.g. curious, fearful, and aggressive) tend to cluster into one or more broader dimensions. An individual’s score on a given dimension corresponds to their position along a particular behavioral continuum (e.g., the shy-bold axis; Wilson, Clark, Coleman, & Dearstyne, 1994). When assessed using standardized methods, comparisons of Personality Structure across species may help researchers address questions about the phylogeny and evolution of Personality (Gosling & Graybeal, 2007). In the case of nonhuman primates (hereafter ‘primates’), King and Figueredo (1997) reported that chimpanzee (Pan troglodytes) Personality is comprised of a species-specific dimension, Dominance, and five dimensions similar to those found in many human Personality studies – Extraversion, Conscientiousness, Agreeableness, Neuroticism, and Openness (e.g., Digman, 1990; Eysenck, 1970; Lee, Ogunfowora, & Ashton, 2005). A study of orangutans (Pongo spp.) using the same scale found dimensions resembling chimpanzee Neuroticism, Extraversion, Agreeableness, and Dominance (Weiss, King, & Perkins, 2006). However, instead of the distinct Conscientiousness and Openness dimensions found in chimpanzees, orangutans have a dimension, Intellect, comprised of traits associated with both. More recently, a study of rhesus macaques (Macaca mulatta) using a comparable instrument found dimensions similar to chimpanzee Openness and chimpanzee/orangutan Dominance (Weiss, et al., 2011). However, unlike chimpanzees and orangutans, rhesus macaques do not have dimensions resembling Extraversion or Neuroticism; rather, traits shared with these dimensions are classified under dimensions labeled Activity (e.g. innovative and playful), Friendliness (e.g. affectionate, sociable, sensitive), Confidence (e.g. stable, dominant, cool), and Anxiety (e.g. impulsive, anxious, erratic). These findings suggest that some Personality dimensions may be phylogenetically old and shared across species (e.g. Dominance-like dimensions), while others may have evolved more recently (e.g. Conscientiousness and Intellect). To date, research on Personality has predominantly been limited to catarrhines, that is apes, including humans, and Old World monkeys (Freeman & Gosling 2010). Platyrrhines (New World monkeys) are only distantly related to catarrhine species, sharing a common ancestor about 43 million years ago (Steiper & Young, 2006). However, some New World species exhibit behavioral and cognitive similarities to catarrhine species, particularly capuchin monkeys (Cebus and Sapajus spp.) and spider monkeys (Ateles spp.) (Amici, Aureli, & Call, 2008; Deaner, van Schaik, & Johnson, 2006; Fragaszy, Visalberghi, & Fedigan, 2004). Thus, comparative studies of Personality in Old and New World species may help identify variables within the natural and social world of primates that contribute to Personality evolution. In this study, we examined Personality Structure in a New World primate, the brown capuchin monkey (Sapajus apella, formerly Cebus apella; Alfaro, Silva, & Rylands, 2012). We first derived Personality Structure in brown capuchins using observer ratings, and examined its association with systematically recorded behaviors. We then compared Personality Structure in brown capuchins to those reported in chimpanzees, orangutans, and rhesus macaques – all of which were rated using the same or similar scale. Ratings of brown capuchin monkeys on individual Personality traits have been associated with cortisol reactivity (Byrne & Suomi, 2002). Thus, human observer ratings capture biologically-meaningful information about this taxon. However, it is unknown how individual traits cluster into Personality dimensions in brown capuchins, and how the Structure of these dimensions compares to those of other primates. Our study was conducted contemporaneously with another study which derived Personality Structure in white-faced capuchins (Cebus capucinus; Manson & Perry, in press). Brown capuchins, chimpanzees, and orangutans have large brains relative to their body size, are extractive foragers, are very tolerant of non-kin, rely on social learning, and have “cultural” traditions (Fragaszy, Visalberghi, & Fedigan, 2004). Moreover, brown capuchins exhibit delayed gratification tolerances more like those of great apes than more closely related platyrrhines such as marmosets (Callithrix jacchus) and tamarins (Saguinus oedipus) (Addessi, Paglieri, & Focaroli, 2011). Unlike semi-solitary orangutans (Rodman, 1984), however, capuchins and chimpanzees are considerably more social and have many of the same basic properties of sociality as other group-living primates, including rhesus macaques. For example, they live in multimale-multifemale groups, have social hierarchies, provide coalitionary support to others, display post-conflict reconciliations, and frequently engage in social grooming (Fragaszy, et al., 2004; Maestripieri & Hoffman, 2012; Stanford, 1998). Thus, collectively, the behavior and cognitive traits of brown capuchins are qualitatively more like those of chimpanzees than other primate species. Individual differences in behavioral and cognitive traits are closely associated with differences in Personality (reviewed in Carere & Locurto, 2011). Thus, given the behavioral and cognitive similarities between brown capuchins and great apes, we hypothesized that the Personality Structure of brown capuchins would overlap more with great apes – and in particular, chimpanzees – than with rhesus macaques.
