CSM

Note: This conference was jointly held with Center for Evolutionary Psychology at University of California, Santa Barbara.

Date: February 23 - 24 , 2008

Location: University Center (UCEN), Fliying A Studio, University of California, Santa Barbara.

Speakers:
Day one:
Taiki Takahashi (Hokkaido University)
Andy Delton and Max Krasnow (University of California, Santa Barbara)
John Tooby (University of California, Santa Barbara)
Aaron Sell (University of California, Santa Barbara)
Mizuho Shinada (Hokkaido University)
Daniel Sznycer (University of California, Santa Barbara)
Tatsuya Kameda (Hokkaido University)

Day two:
Dave Pietraszewski (University of California, Santa Barbara)
Kunihiro Yokota (Hokkaido University)
Mike Gurven (University of California, Santa Barbara)
Kosuke Takemura (Hokkaido University)
Chris VonRueden (University of California, Santa Barbara)
Rie Mashima (Hokkaido University)
Masaki Yuki (Hokkaido University)

Keynote Address
Toshio Yamagishi (Hokkaido University)

Participants:
UCSB: John Tooby, Leda Cosmides, Steven Gaulin, Will Lassek, Daniel Sznycer, Aldo Cimino, Carolyn Hodges, Rose McDermott, Julian Lim, Sangin Kim, Eyal Aharoni, Aaron Sell, Annie Wertz, David Pietraszewski, Elsa Ermer, Max Krasnow, Danielle Truxaw, Chris von Rueden, Zach Simmons, Michael Gurven, James Roney, Bianca Lippert, Aaron W. Lukaszewski, Andy Delton, Tess Robertson, Christina Larson, Brandy Burkett, June Betancourt, Kate Hanson Sobraske, Mike Mrazek, Alex Schwartz, Eric Schniter, Jelle De Schrijver, Tamsin German, Heejung Kim, Rose McDermott.
Hokkaido: Toshio Yamagishi, Tatsuya Kameda, Masaki Yuki, Nobuyuki Takahashi, Keiko Ishii, Taiki Takahashi, Nina Takashina, Mizuho Shinada, Rie Mashima, Shigehito Tanida, Kunihiro Yokota, Kosuke Takemura, Chisato Takahashi, Nobuye Ishibashi, Keigo Inukai, Nobuhiro Mifune, Joanna Schug, Haruto Takagishi, Yukaka Horita, Hirofumi Hashimoto, Kosuke Sato: Total about 60 participants

Schedule and Contents:

Saturday, February 23
9:00 - 9:30 　Presentation 1: Taiki Takahashi
“Neuroeconomics of Intertemporal and Probabilistic Choice”

Free will and rationality have been associated with congruity between one's intention and action, especially by philosophical compatibilists (e.g. David Hume, Thomas Hobbs, Daniel Dennett), and rational choice theorists in social science. However, behavioral economic studies demonstrated that subjects often lack the rational congruity, even in the absence of interferences by other subjects. Thus, behavioral economists increasingly argue that violations of rationality axioms provide a new rationale for paternalism; while several evolutionary psychologists argue strongly against their claims. Therefore, neuroeconomic studies should help biological understandings of the irrationality, by utilizing well-defined behavioral measures, in a quantitative manner. One of the mathematically well-defined discrepancies between one’s intention and action is time-inconsistency in temporal discounting. Time-inconsistent intertemporal choice is formulated with a family of hyperbolic discount functions and a parameter of irrationality in discounting has recently been established. I will introduce our neuroeconomic studies on hyperbolic discounting of delayed and uncertain outcomes. The implications of the introduced neuroeconomic findings for economic policyand evolutionary theory will also be discussed.

9:30 - 10:00 　Presentation 2: Andy Delton and Max Krasnow
“A Cue-Theoretic Approach to Cooperation”

People routinely cooperate with individuals they have never met before and may never see again. Why? Many theorists suggest that this is a by-product of kin selection, selection for direct reciprocity, or selection for maintaining a favorable reputation. Other theorists argue that this cannot be the whole story: People cooperate in anonymous, one-shot experimental settings despite having (a) no reason to believe their partners are kin, (b) no reason to believe they will engage in the repeated interactions that makes direct reciprocity possible, and (c) no reason to believe there is any possibility for others to learn what they have done. Based on this, these theorists propose a variety of cultural or genetic group selection models to explain such one-shot cooperation. By conducting a series of simulations, we show here that such a move is unnecessary: Once the probabilistic nature of cues that discriminate one-shot from repeated interactions is taken into account, selection for direct reciprocity creates agents willing to engage in one-shot cooperation—even when these agents explicitly believe that the interaction is one-shot.

10:30 - 11:00 　Coffee Break

11:00 - 12:10 　Presentation 3: John Tooby and Leda Cosmides
“Towards Constructing a Computational and Adaptationist Approach to Human Motivation: The Case of Kin Detection, Family-directed Altruism, and Incest Avoidance”

Motivation is central to psychology, psychiatry, neuroscience, and the behavioral sciences, but its study has been relatively neglected in recent decades. Even the best developed of existing theories cannot accommodate the great majority of motivational competences that humans exhibit. Traditional approaches to motivation such as drive reduction theories, conditioning theories, preferences, and goal-seeking models, while admirable in many respects, need to be fundamentally reformulated and incorporated into a more encompassing and computationally more explicit theory to account for the full range of motivational phenomena. We have been working on a new theoretical framework for motivation that is both adaptationist and computational to address these limitations. We propose that the motivational architecture contains a heterogeneous set of evolved mechanisms designed to compute a large series of internal regulatory variables (IRVs)—computational elements with magnitudes that dynamically track fitness-relevant aspects of the social, physical, and biotic environment. For example, one IRV that plays a role in many motivational systems is a welfare trade-off ratio (WTR) that is accessed to regulate behaviors that jointly affect one’s own welfare and the welfare of another. Another is the kinship index (KI), which the brain uses to track genetic relatedness between self and familiar other.  The set of IRVs and the mechanisms that compute them are accessed to assign meaning and value to aspects of actual and potential situations, to generate goals and other motivational phenomena, and to arbitrate trade-offs among competing values. This understudied computational substrate coevolved with the adaptive designs of the emotions to produce a suite of mechanisms—the recalibrational components of emotions such as anger, guilt, shame, gratitude, and so on—that we experience as feelings, and that implement the episodic reweighting of IRVs in the light of new information.  We will present a detailed analysis of the architecture of the human kin detection/motivational system as an example of the kind of design we suspect is widespread in our species-typical architecture.

12:10 - 13:30 　Lunch Break

13:30 - 14:00 　Presentation 4: Aaron Sell
“The Computational Structure of Human Anger”

Anger is a complex adaptation whose various design features have so far resisted theoretical explanation largely because an evolutionary functional approach has not been applied.If anger is thought of as an adaptation designed by natural selection to regulate Welfare Tradeoff Ratios (i.e. the extent to which another individual values your welfare relative to their own), then the major features of anger are cogently explained.These features include but are not limited to the typical cost-imposition cause of anger, anger in response to insults, the design of anger-driven arguments, the anger face, the anger voice, the tie to violent aggression and the nature of apologies and justifications.

14:00 - 14:30 　Presentation 5: Mizuho Shinada
“Punishing Free-riders: Direct and Indirect Promotion of Cooperation”

Human cooperation in a large group of genetically unrelated people is an evolutionary puzzle. Despite its costly nature, cooperativebehavior is commonly found in all human societies—a fact that has interested researchers from a wide range of disciplines, including biology,economics, and psychology, to name a few. Many behavioral experiments have demonstrated thatcooperation within a group can besustained when free riders are punished. We argue that punishment has both a direct effect and an indirect effect on promoting cooperation.The direct effect of punishment alters the consequences of cooperation and defection in such a way as to make a rational person prefercooperation. The indirect effect of punishment promotes cooperation among conditional cooperators by providing the condition necessary fortheir cooperation (i.e., the expectation that other members will also cooperate). Here we present data from two one-shot n-person prisoner'sdilemma games, demonstrating that the indirect effect of punishment complements the direct effect to increase cooperation in the game.Furthermore, we show that direct and indirect effects are robust across two forms of punishment technology: either when punishment isvoluntarily provided by game players themselves or when it is exogenously provided by the experimenter.

14:30 - 15:00 　Presentation 6: Daniel Sznycer
“Recalibrational Emotions and Welfare Tradeoff Ratios”

The adaptive problem of making advantageous cost-benefit tradeoffs selected for a class of internal regulatory variables—welfare tradeoff ratios (WTRs)—that regulate the relative weightthe individual places on his/her own welfare versus the welfare of a particular other. The theory investigated is whether specific emotions are designed to recalibrate WTRs functionally in distinct but predictable ways in response to events. Hypotheses derived from the WTR logic predict target-specific WTR downregulation in anger-eliciting situations, and WTR upregulation in guilt- and gratitude-eliciting situations.Evidence from five experiments among Argentine undergraduates that measured the motivation to deliver benefits and the motivation to inflict costs in response to imagined events supports the recalibrational theory of anger, guilt, and gratitude. Differences between those motivations further indicate complex psychological design for making welfare tradeoffs.

15:00 - 15:30 　Coffee Break

15:30 - 16:40 　Presentation 7: Tatsuya Kameda
“"To eat or not to be eaten?": Collective Risk-monitoring in Human Groups”

The importance of risk-monitoring has been increasing in many key aspects of our modern lives.This paper examines how individuals monitor such risks collectively by extending a behavioral ecological model of animal foraging to human groups.Just as animals must forage for food under predatory risk, humans must divide valuable material and psychological resources between foraging activity and risk-monitoring activity.We predicted that game-theoretic aspects of the group situation complicate such a trade-off decision in resource allocation, eventually yielding a mixed equilibrium in a group.When the equilibrium is reached, only a subset of members engage in the risk-monitoring activity while others free-ride, concentrating mainly on their own foraging activity.Laboratory groups engaging in foraging under moderate risk provided a support to this prediction.When the risk-level was set higher, however, “herding behavior” (conforming to the dominant behavior) interfered with the emergence of equilibrium.Implications for risk management are discussed.

17:30 　Poster Session at Mosher Alumni House
Keiko Ishii
“Outgroup Homogeneity Effect in Perception: An Examination in Japan and the US”
Nina Takashino
“Effect of Altruism and Trust on Quasi-Credit: Field Experiments in Central Java”
Shigehito Tanida
“Cooperation in the one-shot Prisoner’s Dilemma Game: Allocation of Attention to the Payoff Matrix”
Chisato Takahashi
“Trust and Reciprocity in the Trust Game: A “Joint-cultural” Experiment in Japan, China, and Taiwan”
Nobuhiro Mifune
“Is Male More Competitive Towards the Outgroup than Female? The Sex Difference of Ingroup Bias”
Nobuye Ishibashi
“Behavioral Assortment in Group Tasks: How do People React to Social-frequency Information in a Group Task with a Marginally-diminishing Return Curve?”
Keigo Inukai
“Decisions Under Ambiguity: Effects of Sign and Magnitude”
Haruto Takagishi
“The Role of Intentions in Third-party Punishment”
Kosuke Sato
“The “Openness” of a Society Determines the Relationship between Self-esteem and Subjective Well-being: A Cross-societal Comparison”
Joanna Schug
“Self-disclosure as a Relationship-strengthening Strategy Adaptive to Mobile Societies”
Yutaka Horita
“Inequity Enhancing Rejection of Unfair Offers: Reasons for Rejection in the Ultimatum Game”
Hirofumi Hashimoto
“Default Adaptive Strategies as a Form of Error Management”
Brandy N. Burkett, Leda Cosmides, John Tooby, & Christina Larson
“Jealousy, Friendship and the Banker’s Paradox”
Eric Schniter
“Culture Across the Lifespan: the Distribution and Ontogeny of Essential Tsimane’ Cultural Skills and Abilities”
William D. Lassek, & Steven J.C. Gaulin
“The Effect of the Type of Dietary Fatty Acids on Body Mass and Cognition”
Tess Robertson
“Emotions Coordinate Responses to Different Exclusions: Evidence for Distinct Exclusion-response Mechanisms”
Carolyn Hodges
“Dominance and Attractiveness Depend on Different Parameters in Men’s Voices: The Relative Roles of Mean Pitch and Pitch Variation”
Aaron W. Lukaszewski, Zachary L. Simmons, & James R. Roney
“Rapid Endocrine Responses of Young Men to Social Interactions with Young Women”
Elsa Ermer
“Relative Status Regulates Risky Decision-making about Resources in Men: Evidence for the Co-evolution of Motivation and Cognition”
Annie E. Wertz & Tamsin C. German
“Core Principles in the Explanation of Behavior: Actions Speak Louder than Words”

Sunday, February 24
9:30 - 10:00 　Presentation 1: Dave Pietraszewski
“Ancestral Conditions Make Modern Day Predictions: Sex, Race, Coalitions & Accent”

Evidence from language acquisition suggests that phoneme repertoires are locally contingent and crystallize roughly around puberty. Thus, shared accents are diagnostic of being raised in the same language community. If immigration and coordination patterns extended across local language communities with sufficient ancestral regularity, and tracking common social origins proved beneficial, then the human cognitive architecture should be designed to represent agents’ accents. New studies demonstrate 1)agents’ accents are spontaneously represented, 2) accent behaves as a different ontological entry than social alliance or race.

10:00 - 10:30　Presentation 2: Kunihiro Yokota
“Adaptive Psychological Mechanisms to Various Types of Intergroup Threats”

The purpose in this study is to explore sex differences in evolved psychological mechanisms adaptive to intergroup conflict. Recent studies have mainly focused on the coevolution between intergroup conflict and ingroup favoritism – behavioral tendency to prefer ingroup members to outgroup members (e.g, Choi & Bowles, 2007). Such behavioral tendency in intergroup conflict was more prevalent in males (e.g., van Vugt et al., 2007). We hypothesized that ingroup favoritism in males is stemmed from general psychological mechanisms for intergroupconflict. In addition to this, there is evidence that when compared to males, females are more sensitive to the contamination threat (e.g., the threat that ingroup would be contaminated by an unknown diseases possessed by outgroups). We also hypothesized that ingroup favoritism in females is stemmed from general psychological mechanisms specified for contamination threat. In study 1, presence/absence of subtle cues of intergroup conflict were manipulated, then measured ingroup favoritism in the minimal group paradigm was measured. Results showed that, as consistent with our predictions, intergroup favoritism occurred only when male participants were primed with intergroup conflict. No intergroup favoritism was shown in female participants in response to such cues. This means that general psychological mechanisms for intergroup conflict are specified for males. In study 2, cues of interpersonal contamination threat were manipulated and intergroup favoritism was measured by participants’ evaluation about the ingroup (Japan) versus outgroups (general foreign countries). We did not find any sex differences in ingroup favoritism when contamination threat was primed. We will discuss possible problems in this experiment.

10:30 - 11:00 　Coffee Break

11:00 - 12:10　Presentation 3: Mike Gurven
“Cooperation Among Hunter-Gatherers”

The economics of a human hunting and gathering lifestyle requires extensive social relationships and implicit social contracts among group members.With this in mind, I explore the evolutionary basis of food sharing and cooperation in small-scale subsistence societies and discuss why production and distribution cannot be understood when viewed as separate phenomena. I also give attention to the role of social norms as focal points for resolving potential conflicts of interests, and to the social psychology underlying sharing decisions.

12:10 - 13:30 　Lunch Break

13:30 - 14:00 　Presentation 4: Kosuke Takemura
“On the Default Assumption of Monitoring and Sanctioning Behind Japanese Collectivism: A View from the Social Institutional Analysis and Error Management Theory”

The popular view of cross-cultural psychology has held that collectivistic behaviors among Japanese can be explained in terms of internalized values/preferences. However, Yamagishi and colleagues have shown the importance of external factors such as the group-level system of monitoring and sanctioning (GMS) of free riders to explain Japanese collectivism (e.g. Yamagishi, 1988).Also, by further elaborating this from the perspective of error management theory, Yamagishi, Jin, and Kiyonari (1999) have hypothesized that Japanese tend to assume the existence of GMS and then cooperate with the ingroup by default even when the existence of GMS is ambiguous, because this assumption is safer in Japanese society where GMS is prevalent and ostracism would be fatal for individuals.Although this hypothesis had remained untested directly for a long time, in this study we examined it by bringing the idea of “removal”: If Factor X is a basis of Behavior X, the degree of Behavior X should decrease when Factor X is removed.We conducted a public goods game experiment in Japan and the United States, and tested if cooperative behavior decreased in each society when participants were clearly told that there was no GMS in the situation.Seventy-six Japanese and fifty-seven American students played a public goods game twice in a 3-person laboratory group.They were asked to decide how much to give to the ingroup from their personal assets, which would be doubled and divided equally among the members.Although all participants decided their contributions at the first trial without being told about the presence/absence of GMS, participants in the no GMS condition were made aware that GMS was non-existent before the second trial.No such emphasis was made in the control condition.As predicted, Japanese with higher ingroup identity decreased cooperation from the first to second trial significantly more than in the no GMS condition than in the control condition. Japanese low-identifiers and Americans did not change their cooperation regardless of the manipulation.

14:00 - 14:30　Presentation 5: Chris VonRueden
“Health and Fertility Correlates of Male Social Status among the Tsimane of Bolivia”

Important to recent evolutionary models of collective action are inter-individual differences in a reputation for cooperativeness (e.g. Milinksi et al. 2002; Panchanathan & Boyd, 2004).Less considered are differential costs in coordinating, sanctioning, or monitoring others or differential benefits expected from a given group project.For example, physically formidable individuals potentially face lower punishment costs, skilled orators are perhaps more effective coordinators, and individuals centrally positioned within a group’s kinship or alliance network are more likely to proffer and benefit from collective actions that are initiated by the group (Tooby et al. 2006).In this talk I investigate which traits confer greater social influence, both dyadic and polyadic, among the Tsimane forager-horticulturalists of Bolivia.The predictors of influence I evaluate include physical size, personality traits, skill, wealth, and social support.Furthermore, I present data on fertility and health correlates of social influence within this population.

14:30 - 15:00　Presentation 6: Rie Mashima
“How Do We Treat Givers to Free-Riders in Indirect Reciprocity Settings? An Experimental Study to Examine Strategies in Indirect Reciprocity Settings”

Recent theoretical studies suggest that the key to the emergence of indirect reciprocity is discriminate altruism based on not only 1st-order information (others' previous behaviors) but also 2nd-order information (reputation regarding targets of others' previous behaviors).We conducted a laboratory experiment to examine people's actual strategies in indirect reciprocity settings.Participants played a repeated giving game in eight-person groups.In each round, participants were endowed 50 yen and asked to decide whether to give it to one of the other participants or keep it for themselves.When they made their decisions, they could see 1) 1st-order information: whether each target gave or did not give in the last round and 2) 2nd-order information: whether the person had given to a giver or a non-giver in the last round.Results showed that participants used not only 1st-order information (gave more to previous givers than to previous non-givers) but also 2nd-order information (gave more to the persons who had given to givers than to the persons who had given to non-givers).These results are consistent with Takahashi and Mashima (2006)'s conclusion, suggesting that the key to the emergence of indirect reciprocity is to exclude not only free-riders but also indiscriminate givers who help free-riders.Further analysis suggested that altruistic sentiments toward givers to givers, rather than punitive sentiment toward givers to free-riders, form the motivational basis of such strict discrimination (excluding those who gave to free-riders) in indirect reciprocity settings.

15:00 - 15:30 　Coffee Break

15:30 - 16:40 　Presentation 7: Masaki Yuki
“The "Openness" of a Society Determines the Relationship between Self-Esteem and Subjective Well-Being: A View from the Socio-Ecological Perspective”

In this talk, I will give an example of how evolutionary, or adaptationist, approach, which focuses on the nature of socio-ecological environment, can be applied to explain cross-cultural differences in social behavior and social psychological processes of, at least, humans. Previous studies have shown that the impact of self-esteem on subjective well-being (SWB) is generally stronger in North America than in East Asia. This difference has been explained typically in terms of cultural differences in ‘self-construals.’ However, we propose that this difference can be explained more logically in terms of differences in relational mobility, a socio-ecological factor reflecting the amount of opportunities for individuals to form new relationships, when necessary, in a given society. Societies high in relational mobility, such as the US, are comprised of open markets of interpersonal relations where people constantly invest effort into finding superior interaction partners with whom to establish relationships. In this competitive marketplace, self-esteem, or one’s market value, directly predicts one’s success in forming desirable relationships, and is thus strongly associated with SWB. However, societies low in relational mobility, such as East Asia, one’s success in acquiring desirable interpersonal relationships is affected by one’s market value to a lesser extent, as relationships are generally predetermined and stable. We conducted a series of multi-method studies to test this hypothesis. Throughout the studies, we consistently found stronger correlations between self-esteem and SWB in the societies/social contexts high, rather than low, in relational mobility..

16:40 Break

18:00 Banquet at Faculty Club

19:30 Keynote Address: Toshio Yamagishi
“In-group Favoring Behavior as a Reputation Device”

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