About

Leda Cosmides is a professor in the Department of Psychological and Brain Sciences at the University of California, Santa Barbara, within the Department of Anthropology. Her specialization is indicated through her departmental affiliation, and her contact information includes an email address (cosmides@psych.ucsb.edu) and a departmental webpage. The page does not provide specific details about her research focus, background, or key contributions, but her role as a professor suggests involvement in teaching and research within her field.

Research topics

• Political Science
• Psychology
• Social psychology
• Economics
• Sociology
• Computer Science
• Microeconomics
• Law
• Philosophy
• Epistemology

Selected publications

• Through the lens of adaptationism: Commentary on Baumard & André

  Evolution and Human Behavior · 2025-07-19 · 2 citations

  article1st authorCorresponding
  PublisherDOI

• Willingness to protect from violence, independent of strength, guides partner choice

  Evolution and Human Behavior · 2025-08-30 · 1 citations

  articleSenior author
  PublisherDOI

• Willingness to protect from violence, independent of strength, guides partner choice

  2025-09-01

  articleOpen accessSenior author

  Ancestrally, physical violence from conspecifics was a recurrent adaptive problem. Did selection favor preferences for partners who are both strong (highly able) and willing to protect us from violence? Strength and willingness are interrelated, so dissociating their effects is necessary. Here we assessed both inferences and preferences. In 7 experiments (N = 4,508 U.S. adults recruited via MTurk), we systematically varied the willingness of a date or friend to physically protect you from an attack, compared to scenarios where you do not have this information. We also varied that person’s strength. Discovering that a person is willing to protect greatly increased their attractiveness as a romantic partner or friend, regardless of their strength. This held for both women and men raters, and when evaluating both opposite- and same-sex dates and friends. In fact, partners who were willing to protect were attractive even if they tried to do so but failed, and even if you were harmed because of their failure. Discovering that a partner is unwilling to protect decreased their attractiveness, and was a deal-breaker for women evaluating a male date. Unwillingness decreased attractiveness more when the rater was a woman, when the target was a man, and when the target was being evaluated as a date versus friend. Women placed some importance on a male date’s strength, but this was mostly due to inferences about his willingness to protect them. Surprisingly, we found only weak evidence that differences in strength, independent of willingness, increased the attractiveness of a partner.

  PublisherOA PDFDOI

• Coalitional support regulates resource divisions in men

  Evolution and Human Behavior · 2025-06-16 · 1 citations

  articleSenior author
  PublisherDOI

• The evolution of war and its cognitive foundations

  Evolution and Human Behavior · 2025-04-17 · 29 citations

  articleSenior authorCorresponding
  PublisherDOI

• The Past Explains the Present

  Oxford University Press eBooks · 2024-05-22 · 1 citations

  book-chapterSenior author

  Abstract Present conditions and selection pressures are irrelevant to the present design of organisms; they do not explain how or why organisms behave adaptively, when they do. To whatever non-chance extent organisms are behaving adaptively, it is (1) because of the operation of underlying adaptations whose present design is the product of selection in the past, and (2) because present conditions resemble past conditions in those specific ways made developmentally and functionally important by the design of those adaptations. All adaptations evolved in response to the repeating elements of past environments, so their design reflects the recurrent properties of those environments. Emotions are adaptations that treat the present as a version of the past. They categorize new situations as instances of evolutionarily recurrent events that posed adaptive problems with large fitness consequences. When activated, an emotion coordinates suites of cognitive and physiological adaptations, in ways well-designed for solving those ancestral problems.

  PublisherDOI

• Cognitive foundations for helping and harming others: Making welfare tradeoffs in industrialized and small-scale societies

  Evolution and Human Behavior · 2023 · 30 citations

  • Political Science
  • Psychology
  • Social psychology
  PublisherDOI

• Group as a biological market: Eliminating reputation concern decreases ingroup-favouring cooperation and punishment

  2023-07-07 · 1 citations

  preprintOpen accessSenior author

  Accumulating evidence suggests that group is a cue of reputation-based partner choice: it evokes an assumption that one is being recognized and evaluated as a cooperation partner and thereby triggers reputation concern. For instance, studies have demonstrated that people cooperate more with ingroup than outgroup members, but this bias disappears when the beneficiary does not know the donor is a fellow ingroup member and, thus, is unlikely to evaluate the donor as a partner. Here, we further examined this hypothesis by (i) testing whether people avoid reputation-harming behaviour, such as second-party punishment, and (ii) manipulating anonymity instead of membership knowledge. Across three experiments (N = 723), participants were less likely to punish ingroup than outgroup partners, while cooperating more with ingroup partners. However, when participants were anonymous, the degree to which people favoured ingroup decreased regardless of study setting (online vs. in-person) or sample (convenience vs. college). That is, without reputation concern, people donated less to ingroup members and were less hesitant to punish them. The results illustrate that our mind perceives one’s group as a “market” for cooperation partners and employs a default reputation-management strategy—up-regulating motivations to cooperate while down-regulating punitive motivations—unless other cues challenge its necessity.

  PublisherOA PDFDOI

• Rational inferences about social valuation

  2023-04-20 · 1 citations

  preprintOpen accessSenior author

  The decisions made by other people can contain information about the value they assign to our welfare---for example how much they are willing to sacrifice to make us better off. An emerging body of research suggests that we extract and use this information, responding more favorably to those who sacrifice more even if they provide us with less. The magnitude of their trade-offs governs our social responses to them—including partner choice, giving, and anger. This implies that people have well-designed cognitive mechanisms for estimating the weight someone else assigns to their welfare, even when the amounts at stake vary and the information is noisy or sparse. We tested this hypothesis in two studies (N=200; US samples) by asking participants to observe a partner make two trade-offs, and predict the partner's decisions in other trials. Their predictions were compared to those of a model that uses statistically optimal procedures, operationalized as a Bayesian ideal observer. As predicted, (i) the estimates people made from sparse evidence matched those of the ideal observer, and (ii) lower welfare trade-offs elicited more anger from participants, even when their total payoffs were held constant. These results support the view that people efficiently update their representations of how much others value them. They also provide the most direct test to date of a key assumption of the re-calibrational theory of anger: that anger is triggered by cues of low valuation, not by the infliction of costs.

  PublisherOA PDFDOI

• Reply to Greene: No version of the dual process model can explain rational performance by people who made compromise moral judgments

  Proceedings of the National Academy of Sciences · 2023-06-06 · 1 citations

  letterOpen access1st authorCorresponding

  Proceedings of the National Academy of Sciences (PNAS), a peer reviewed journal of the National Academy of Sciences (NAS) - an authoritative source of high-impact, original research that broadly spans the biological, physical, and social sciences.

  PublisherDOI

Recent grants

• NIH Grant DP1OD000516

  NIH · $2.9M · 2012

• The Hidden Correlates of Social Exclusion

  NSF · $400k · 2010–2014

Frequent coauthors

• John Tooby

  University of California, Santa Barbara

  151 shared

• Daniel Sznycer

  Oklahoma State University Oklahoma City

  33 shared

• Robert T. Knight

  University of California, Berkeley

  20 shared

• Andrew W. Delton

  Stony Brook University

  17 shared

• Aaron Sell

  Heidelberg University

  17 shared

• Valerie E. Stone

  16 shared

• Neal E. A. Kroll

  16 shared

• Stanley B. Klein

  University of California, Santa Barbara

  14 shared