Research on primate personality and social relationships




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The Transdisciplinary Philosophy-of-Science Paradigm for Research on Individuals (TPS-Paradigm)

TPS-Paradigm: Theoretical, metatheoretical and methodological papers

Empirical studies with nonhuman primates using the TPS-Paradigm

Personality questionnaires for nonhuman primates

Empirical studies with nonhuman primates using the TPS-Paradigm

Great Apes: chimpanzees (Pan troglodytes), bonobos (Pan paniscus), gorillas (Gorilla gorilla), orangutans (Pongo abelii; Pongo pygmaeus)

Crab-eating macaques (Macaca fascicularis), also known as long-tailed macaque; Java monkey, cynomolgus monkey

Capuchin monkeys (Sapajus spp., formerly Cebus apella)

Comparative study involving Weeper capuchin monkeys (Cebus olivaceus), mandrills (Mandrillus sphinx), toque macaques (Macaca sinica) and rhesus macaques (Macaca mulatta)


Abstracts and PDF-Downloads

Uher, J., & Visalberghi, E. (2016). Observations versus assessments of personality: A five-method multi-species study reveals numerous biases in ratings and methodological limitations of standardised assessments. Journal of Research in Personality, 61, 61-79.  [Download]  [Supplemental Material]  DOI: 10.1016/j.jrp.2016.02.003  
Personality assessments and observations were contrasted by applying a philosophy-of-science paradigm and a study of 49 human raters and 150 capuchin monkeys. Twenty constructs were operationalised with 146 behavioural measurements in 17 situations to study capuchins' individual-specific behaviours and with assessments on trait-adjective and behaviour-descriptive verb items to study raters' pertinent mental representations. Analyses of reliability, cross-method coherence, taxonomic structures and demographic associations highlighted substantial biases in assessments. Deviations from observations are located in human impression formation, stereotypical biases and the findings that raters interpret standardised items differently and that assessments cannot generate scientific quantifications or capture behaviour. These issues have important implications for the interpretation of findings from assessments and provide an explanation for their frequent lack of replicability.


Uher, J. (2015e). Comparing individuals within and across situations, groups and species: Metatheoretical and methodological foundations demonstrated in primate behaviour. In D. Emmans & A. Laihinen (Eds.). Comparative Neuropsychology and Brain Imaging (Vol. 2), Series Neuropsychology: An Interdisciplinary Approach. (chapter 14, pp. 223-284). Berlin: Lit Verlag. [download]  ISBN 978-3-643-90653-3  DOI: 10.13140/RG.2.1.3848.8169
Individuals are explored in various kinds of phenomena and contexts. But how can scientists compare individual variations across phenomena with heterogeneous properties that require different methods for their exploration? How can measurements of individual variations be made directly comparable between different studies, groups of individuals or even species? This research applies the Transdisciplinary Philosophy-of-Science Paradigm for Research on Individuals (TPS-Paradigm) to elaborate metatheoretical concepts and analytical methodologies for quantitative comparisons of individual variations within and across situations, groups and species using behavioural phenomena as examples. Established concepts from personality psychology, differential psychology and cross-cultural and cross-species research are systematically integrated into coherent frameworks and extended by adding concepts for comparing individual-specific variations (i.e., “personality”) between species. Basic principles for establishing the functional comparability of behavioural and situational categories are elaborated while considering that individuals from different groups and species often show different behaviours and encounter different situations and therefore cannot be studied with identical variables as is done in assessment-based research. Building on these principles, the chapter explores methodologies for the statistical analyses of the configurational comparability of constructs and of mean-level differences between groups and species. It highlights that situational properties are crucial for quantitative comparisons of individual variations. Fundamental differences between observational methods and assessment methods are explored, revealing serious limitations and fallacies inherent to comparisons of individuals on the basis of assessments. Implementations of the methodological principles and concepts presented are illustrated with behavioural data from four primate species (weeper capuchins, mandrills, toque macaques and rhesus macaques).


Uher, J., Werner, C. S. & Gosselt, K. (2013). From observations of individual behaviour to social representations of personality: Developmental pathways, attribution biases, and limitations of questionnaire methods. Journal of Research in Personality, 47, 647–667. [download]   DOI: 10.1016/j.jrp.2013.03.006
Socio-cognitive abilities to recognise and to represent individual-specificity-even in some nonhuman species-are central to human life. Using a novel philosophy-of-science paradigm, we explored these abilities over 3 years in 6 waves by investigating individual-specific behaviours of 104 crab-eating macaques (Macaca fascicularis) and the representations that 99 human observers-experts and novices-developed of them. By applying the non-lexical Behavioural Repertoire x Environmental Situations Approach, we generated 18 macaque-specific personality constructs. They were operationalised with behavioural measures to study the macaques and with two rating formats to study the observers' representations. Analyses of reliability, cross-method coherence, taxonomic structures, associations with demographic factors, and 12-24-month stabilities highlighted essential differences between individual-specific behaviours and pertinent representations, explored developmental pathways of representations, and illuminated attribution biases and limitations of questionnaire methods.  
Uher, J., Addessi, E., & Visalberghi, E. (2013). Contextualised behavioural measurements of personality differences obtained in behavioural tests and social observations in adult capuchin monkeys (Cebus apella). Journal of Research in Personality, 47, 427–444.  [download paper; download supplemental material]   DOI: 10.1016/j.jrp.2013.01.013
We applied a new framework for behavioural research on personality differences in 26 adult tufted capuchin monkeys. Using the Behavioural Repertoire x Environmental Situations Approach, we generated systematically 20 non-lexical emic personality constructs that have high ecological validity for this species. For construct operationalisation, we obtained 141 contextualised behavioural measures repeatedly in 15 experimental situations and 2 group situations using computerised and video-assisted methods. A complete repetition after a 2-3-week break within a 60-day period yielded significant test-retest reliability from individual-oriented and variable-oriented viewpoints at different levels of aggregation. In accordance with well-established findings on cross-situational consistency, internal consistency was only moderate. This new and important finding highlights fundamental differences between behavioural approaches and judgment-based approaches to personality differences. 


Uher, J. (2011b). Personality in nonhuman primates: What can we learn from human personality psychology? In A. Weiss, J. King, & L. Murray (Eds.). Personality and Temperament in Nonhuman Primates (pp. 41-76). New York, NY: Springer. [downloadDOI: 10.1007/978-1-4614-0176-6_3  

Primate personality research encounters a number of puzzling methodological challenges. Individuals are unique and comparable at the same time. They are characterized by relatively stable individual-specific behavioral patterns that often show only moderate consistency across situations. Personality is assumed to be temporally stable, yet equally incorporates long-term change and development. These are all déjà-vus from human personality psychology. In this chapter, I present classical theories of personality psychology and discuss their suitability for nonhuman species. Using examples from nonhuman primates, I explain basic theoretical concepts, methodological approaches, and methods of measurement of empirical personality research. I place special emphasis on theoretical concepts and methodologies for comparisons of personality variation among populations, such as among species. 

Uher, J. & Asendorpf, J. B. (2008). Personality assessment in the Great Apes: Comparing ecologically valid behavior measures, behavior ratings, and adjective ratings. Journal of Research in Personality, 42, 821-838[download]  DOI: 10.1016/j.jrp.2007.10.004
  Three methods of personality assessment (behavior measures, behavior ratings, adjective ratings) were compared in 20 zoo-housed Great Apes: bonobos (Pan paniscus), chimpanzees (Pan troglodytes verus), gorillas (Gorilla gorilla gorilla), and orangutans (Pongo pygmaeus abelii). To test a new bottom-up approach, the studied trait constructs were systematically generated from the species’ behavioral repertoires. The assessments were reliable, temporally stable, and showed substantial cross-method coherence. In most traits, behavior ratings mediated the relations between adjective ratings and behavior measures. Results suggest that high predictability of manifest behavior is best achieved by behavior ratings, not by adjectives. Empirical evidence for trait constructs beyond current personality models points to the necessity of broad and systematic approaches for valid inferences on a species’ personality structure. 

Uher, J., Asendorpf, J. B., & Call, J. (2008). Personality in the behaviour of great apes: Temporal stability, cross-situational consistency and coherence in response. Animal Behaviour, 75, 99-112. [download]  DOI: 10.1016/j.anbehav.2007.04.018
Using a multidisciplinary approach, the present study complements ethological behaviour measurements with basic theoretical concepts, methods and approaches of the personality psychological trait paradigm. Its adoptability and usefulness for animal studies is tested exemplarily on a sample of 20 zoo-housed great apes (five of each of the following species): bonobos, Pan paniscus; chimpanzees, Pan troglodytes verus; gorillas, Gorilla gorilla gorilla; and orang-utans, Pongo pygmaeus abelii. Data on 76 single trait-relevant behaviours were recorded in a series of 14 laboratory based situations and in two different group situations. Data collection was repeated completely after a break of two weeks within a 50-day period. All behaviour records were sufficiently reliable. Individual- and variable-oriented analyses showed high/substantial temporal stability on different levels of aggregation. Distinctive and stable individual situational and response profiles clarified the importance of situations and of multiple trait-relevant behaviours. The present study calls for a closer collaboration between personality psychologists and behavioural biologists to tap the full potential of animal personality research. 

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