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Evolution, Mind, and Behavior Conference at UCSB

Winter Quarter 2006


Joint UCLA-UCSB Conferences held quarterly by

UCSB’s Evolution, Mind, and Behavior Program (EMB)  and

UCLA’s Human Nature and Society Program (HNAS)


Saturday 4 February 2006

Location: Flying A Studio, University Center (UCEN), UCSB

(see directions below)


10:00  AM  Breakfast buffet opens

10:30  AM  First talk: Joseph H. Manson, Father-Daughter Inbreeding Avoidance Reduces Male Reproductive Skew in a Wild Primate Population (with Laura Muniz, Susan Perry, Hannah Gilkenson, Julie Gros-Louis, & Linda Vigilant)

12:00  PM  Lunch (UCEN, no host)

  1:30  PM  Second talk:  Paul J. Zak, The Neuroeconomics of Trust

  3:00  PM  Coffee break

  3:30  PM  Third talk:  John Tooby, The Neurocomputational Architecture of Kin Detection in Humans (with Debra Lieberman & Leda Cosmides)

  5:30  PM Adjourn for no-host dinner, Ming Dynasty (see below)




 Joseph H. Manson  UCLA Anthropology  email

Father-Daughter Inbreeding Avoidance Reduces Male Reproductive Skew in a Wild Primate Population (with Laura Muniz, Susan Perry, Hannah Gilkenson, Julie Gros-Louis, & Linda Vigilant)



Abstract. Inbreeding reduces fitness in various taxa, and several behavioral and physiological mechanisms have evolved that inhibit fertile matings between close kin. Most commonly, members of one or both sexes disperse before breeding. In primates, males usually disperse and females often benefit from lifelong relationships with maternal kin within the group. Females thus risk breeding with their father if the tenure length of the dominant male, who usually sires most group offspring, exceeds the time it takes daughters to mature. Attempts to determine whether such co-resident father-daughter pairs systematically avoid inbreeding have produced equivocal results, and no published studies have addressed this question by genetically ascertaining paternity in a wild population. We determined paternity for 117 wild white-faced capuchins (Cebus capucinus) born into our study population. As expected, alpha males dominated reproduction. However, while siring the great majority (79%) of the offspring born to unrelated females, alphas sired only 6% (1 of 17) of the offspring conceived by their daughters during their tenures, providing evidence for effective inbreeding avoidance without female dispersal.


Lunch, UCEN



Paul J. Zak   Center for Neuroeconomics & Dept. of Economics, Claremont Graduate Univ. email

The neuroeconomics of trust


AbstractThis talk will survey 5 recent studies that are beginning to identify the neural substrates that support interpersonal trust. Trusting strangers routinely is a biologically unusual behavior, yet humans do this quite easily and without much introspection. I will discuss our findings for the role of oxytocin in supporting trust, the relationship between aggression and distrust, including gender differences, and will highlight new functional imaging findings.



Blood sugar break



John Tooby    UCSB Center for Evolutionary Psychology & Dept. of Anthropology  email

The Neurocomputational Architecture of Kin Detection in Humans (with Debra Lieberman & Leda Cosmides)


Abstract. Since Hamilton’s (1964) seminal paper, biologists have increasingly documented that, for social species, natural selection favors the evolution of mechanisms that distinguish genetic relatives from non-relatives, and that use this information to direct altruistic behavior differentially to close genetic relatives. Equally, inbreeding depression among close genetic relatives is a strong selection pressure favoring the evolution of systems of incest avoidance in long-lived species like humans with an open breeding structure. While kin detection systems are suspected to exist in humans and to partially govern family-directed behavior, their existence, information-processing architecture, and neural basis have not yet been clearly documented. If such mechanisms exist, their two motivational functions should allow the architecture of the system to be mapped. This can be done by quantitatively matching individual variation in (1) intensity of altruistic dispositions to various family members and (2) opposition to incest, to (3) individual variation in developmental parameters, such as natal family structure and length of coresidence. Using this research strategy, we began mapping the sibling-directed components of these motivational circuits. I will present converging evidence for a neurocomputational mechanism--a kinship estimator--that integrates cues of relatedness to produce an internal regulatory variable, a kinship index, for each individual who is a (possible) genetic relative. This computational variable is then taken as input into motivational subcircuits that use them (as predicted) to regulate altruism (i.e., acts and reported intensities of caring) and to regulate the intensity of disgust at the prospect of incest with a given individual. All of this machinery lies outside the explanatory scope of drive theory, reinforcement theory, or goal-based approaches to motivation. It provides an example of how one can take a computational approach to understanding the architecture of human motivational systems.



Self-funded dinner at Ming Dynasty

(Ming Dynasty 805-968-1308, 290 Storke Road, at the intersection of Storke and Hollister in Goleta. In the unlikely event you are coming from 101, take Storke exit North of UCSB).


Cosponsored by the UCSB Center for Evolutionary Psychology and the UCLA Center for Behavior, Evolution and Culture. This event is organized as a working seminar for faculty and graduate students. For their generous support of this conference, we thank the UCSB Division of Math, Life, and Physical Sciences, the Division of Social Sciences, and the College of Letters and Sciences. For more information, please contact Leda Cosmides or John Tooby or call 805-893-8720.


UCLA and UCSB will hold two conferences per year, alternating between the two campuses.


Map of the UCSB campus (University Center is at coordinate F3)

There may be car pools coming from UCLA; ask Alan Fiske and Clark Barrett.



Take 101 North toward Santa Barbara. There is a double exit (Patterson; then 217 UCSB / Airport). Take the 217 UCSB exit. Follow the signs to campus (when road forks, take the left fork)

When you come into UCSB from 217, there is a UCSB gate & kiosk. Stop there to get a campus map. Turn left onto Lagoon Road (ocean on your left), then RIGHT onto Ucen road, and park in one of the lots.



UCSB will honor parking stickers issued by UCLA, as long as these are prominently displayed on the lower left side of your windshield. If you do not have a UCLA sticker, please note that parking has changed at UCSB.  You cannot park in places marked "Enforced 24 hours".  Other spaces are numbered and you need to get a ticket, which can be bought from a machine in the parking lot. The closest lot is #3 (but this has a number of illegal spaces, so be careful). Other close lots are #7, 9, and 4.  See map for lot location.