Janko Međedović – Awarded for Outstanding Achievement in the Early Phase of a Scientific Career „Nenad Havelka”

Behavioral ecology of personality: bridging personality evolution between humans and other animals


Behavioral ecology of personality is a field within evolutionary behavioral ecology that tries to provide answers on three evolutionary puzzles of animal personality: the existence of inter-individual variation in behavior, diminished intra-individual variation, and associations between functionally different personality traits. Human personality ecology applies the same conceptual framework in explaining these phenomena in humans. The main goal of the present talk is to present the models from animal personality ecology that we can use in human research with emphasize on natural selection, state-dependent models, and evolutionary tradeoffs. We will show empirical examples, including our own data, to illustrate evolutionary mechanisms that can help in answering on three puzzles of personality (highlighting the first one, due to a highest amount of empirical data) in the context of Big Five and HEXACO personality traits, and psychopathic personality traits. Namely, the existing findings show that disruptive selection may maintain genetic variation in Conscientiousness trait because both extremes on the trait can have elevated fitness, while intermediate scorers have the lowest fitness: this finding is explained by a variation in family planning. Variation in environmental harshness moderates the links between Honesty-Humility trait and fitness, where low levels of the trait are adaptive in harsh environmental conditions but high levels of the trait enable increased fitness in beneficial environments. Quite similarly, environmental harshness (dysfunctions in primary family) may maintain the variation in affective psychopathy characteristics. Quantity-quality tradeoff (the tradeoff between number of offspring and parental investment) is a potential candidate for explaining the variation in trait Neuroticism and affective facet of psychopathy. The tradeoff between mating and parenting has been linked to psychopathy as well, but surprisingly, not the tradeoff between fertility and longevity. At the end, we provide the overview of field’s conceptual significance and outstanding questions for future research.

Janko Međedović holds a PhD in psychology and works at Institute of Criminological and Sociological Research as a Senior research associate; he also works as a lecturer at the Faculty of media and communications where he teaches the following courses: Psychology of Individual Differences, Evolution of Human Behavior, and Research Methodology and Statistics. He explores two broad topics in his research; the first is human behavioral ecology. Within this field, he analyzes the associations between various behavioral dispositions and the indicators of evolutionary fitness with an accent on ecological conditions and internal states that moderate these associations. Furthermore, he contributed to the conceptual advancement and measurement practices within the topic of human life history by applying a network approach to the conceptualization and measurement of life histories. Recently, he turned his focus to the processes closely related to fitness, like reproductive motivation, and parental and general kin effects that can contribute to the understanding of fertility decline in populations undergoing demographic transition. The second research direction covers behavioral dispositions towards criminal behavior and wide-scale violence. Within this field, he examines “dark” personality traits (with a focus on psychopathy and sadism), militant extremist mindset and the ethos of conflict. He is particularly interested in emotional processes linked to psychopathy and sadism and their associations with criminal behavior and recidivism. He published more than 80 scientific manuscripts in peer-reviewed journals; he served as the reviewer for several scientific journals and has been a board member of the Proceedings of the Institute of Criminological and Sociological Research.