Debra Lieberman

Associate Professor in the Department of Psychology

University of Miami

The non-relativity of relatedness: Psychological adaptations underlying kin detection, inbreeding avoidance, and altruism.

April 20th, 2015

Academic Building A G008, 5:05 PM

Abstract

Kinship is a fundamental relationship in biology at all levels of organization, from cellular to cultural. Genetic relatedness amongst cooperating cells is a reason multicellular organisms do not disintegrate; likewise, family structures organize cultural patterns of mating, warring, and cooperation. The primacy of kinship cannot be understated. Yet, in the wake of Hamilton’s publication of inclusive fitness theory 50 years ago, researchers have still not fully identified the information processing systems and underlying neural mechanisms that govern kin-directed behaviors—in humans or any other species. In this talk, I discuss work I’ve conducted over the past few years that begins to uncover the computational mechanisms underlying two distinct kin-directed behaviors in humans: inbreeding avoidance and altruism. Specifically, my collaborators and I have (i) proposed a computational model of kin-based behaviors; (ii) found that two cues—childhood coresidence duration, a cue first proposed by Edward Westermarck, and observations of maternal-infant association—are used to implicitly categorize another as a sibling; (iii) found that across several cultures we have explored, childhood coresidence duration and observations of maternal-infant association predict sexual aversions associated with inbreeding and altruistic motivations between actual genetic siblings; (iv) established that these cues operate even between genetically unrelated individuals explaining the sexual aversions, marital patterns, and altruism of co-reared peers in Israeli Kibbutzim and the fertility patterns of Taiwanese minor marriages; (v) discovered that major histocompatibility complex (MHC) alleles, which are used as cues to kinship in some non-human animals, are not used as a cue to siblingship in humans; and, (vi) initiated research that expands beyond siblingship to uncover how fathers detect offspring. Overall, I stress the non-relativity of relatedness, that is, the presence of an identifiable, universal human psychology that facilitates kin identification and governs behaviors in a fitness promoting fashion.

Biography

Debra Lieberman is an Associate Professor in the Department of Psychology at the University of Miami. She earned a BS in Biochemistry at Binghamton University under the tutelage of Dr. David Sloan Wilson, and a PhD at the Center for Evolutionary Psychology, University of California, Santa Barbara. She has published in the areas of kinship, emotion, and morality. Her current research interests include human kin detection, gratitude and its role in the formation of friendships, and the role emotions play in the legal sphere.

Reading

Reading will be posted to the EvoS blackboard group. Anyone with a Binghamton University email address can request to be added to the blackboard group by emailing EvoS[at]binghamton[dot]edu.

Video

Will be available within a week of the talk.