Jaimie Krems

Oklahoma State University | Oklahoma State · Department of Psychology

The ability to create lasting, trust-based friendships makes it possible for humans to form large and coherent groups. The recent literature on the evolution of sociality and on the network dynamics of human societies suggests that large human groups have a layered structure generated by emotionally supported social relationships. There are also ge...

Intrasexual conflict may pose unique challenges for women. Whereas men’s aggression tends to be physical and direct, women’s tends to be relational and indirect, particularly when directed toward other women. Moreover, women’s expressions of anger are often suppressed, perhaps particularly when other women are the targets. Thus, women may face diff...

For women, forming close, cooperative relationships with other women at once poses important opportunities and possible threats-including to mate retention. To maximize the benefits and minimize the costs of same-sex social relationships, we propose that women's mate guarding is functionally flexible and that women are sensitive to both interperson...

Maslow’s self-actualization remains a popular notion in academic research as well as popular culture. The notion that life’s highest calling is fulfilling one’s own unique potential has been widely appealing. But what do people believe they are doing when they pursue the realization of their full, unique potentials? Here, we examine lay perceptions...

Women’s intrasexual competition has received significant attention only in the last decades, with even less work investigating women’s defenses against such aggression. Yet, we should expect that women can (a) grasp which perceptually-salient cues evoke same-sex aggression and (b) strategically damp the display of (some of) those cues when aggressi...

From the biblical lex talionis to the medieval wergild system and modern workers’ compensation laws, laws about bodily damage may originate from cognitive mechanisms that capitalize on an enduring regularity: Different body parts vary in their incremental contributions to human functionality. To evaluate this hypothesis, we conducted a preregistere...

What characteristics make a person a formidable competitor or a threatening rival? Regardless of the realm of competition, a rival’s perceived level of competitive threat should comprise both rival willingness and ability to compete for a mutually desired outcome. We apply this logic to heterosexual women’s intrasexual mating competition, where wom...

People vent, as when airing grievances about one mutual friend to another. Contrary to a Freudian account, such social venting does not alleviate anger. So, what function might it serve? That people bestow more and more likely support on relatively better-liked friends—support which is associated with greater health, happiness, and economic mobilit...

Friendship is a unique and underexplored area of human sociality. Research suggests that humans have preferences for characteristics in their friends that maximize the benefits of these relationships. Yet, whereas more friends might increase friendship benefits, humans also have limited time, resources, and energy to invest in finding high-quality...

Research on close relationships often focuses on the dyad (e.g., dyads of romantic partners) and on how dyad members affect each other’s welfare. But dyads exist embedded in broader, densely-interconnected social networks, and less research attention has been paid to the myriad ways in which people outside the dyad impact one’s welfare through thei...

Attending to women's intrasexual competition generates a straightforward prediction: Insofar as women actors sometimes use distinct tactics of aggression (e. g., related to social exclusion), women targets might possess distinct interpretations of and reactions to those tactics. We test this using one such tactic common among women: disgust express...

Weight stigma is a chronic stressor and may contribute to cardiometabolic health risk. This pilot study tests an experimental protocol exploring acute inflammation as a potential biological mechanism connecting weight stigma and disease risk. Preliminary effect sizes and protocol feasibility were assessed. Women (N = 44, 68% White) with overweight/...

The COVID‐19 pandemic has led to a worldwide increase in the use of face masks to prevent viral transmission. However, as mask‐wearing was a new behavior in many countries, there was a limited understanding of how mask‐wearers are perceived and how such perceptions impact one's own mask‐wearing behavior. Mask‐wearers may be seen as contagious or pr...

Friendship is a unique and underexplored area of human sociality. Research suggests that humans have preferences for characteristics in their friends that maximize the benefits of these relationships. Yet, whereas more friends might increase friendship benefits, humans also have limited time, resources, and energy to invest in finding high-quality...

Food sharing is central to the human experience, serving biological and sociocultural functions. Historically, food sharing has allowed people to manage food shortages, creating positive interdependence among those who pool calories and other sources of risk. However, sharing food may lead to negative outcomes when food is scarce, or when there is...

Beyond being painful, fat stigma might facilitate pernicious consequences; over and above one’s weight, fat stigma is associated with lesser wellbeing, poorer health, greater all-cause mortality, and weight gains that perpetuate the weight-stigma cycle. To combat fat stigma effectively requires an understanding of the perceptual calculus underlying...

Evolutionary social science is having a renaissance. This volume showcases the empirical and theoretical advancements produced by the evolutionary study of romantic relationships. The editors assembled an international collection of contributors to trace how evolved psychological mechanisms shape strategic computation and behavior across the life s...

Friendships are valuable relationships that can bestow many benefits. How can humans ensure they receive the maximum benefits with minimal potential costs? One possible solution is to have preferences for traits, expectations, and rules in friendship. This could, for example, help people pursue beneficial friendships and jettison costly friendships...

Courts in seven U.S. states have removed children with "obesity" from parental custody until children could maintain "healthy weights." These rulings-alongside qualitative reports from parents of children with high weight (PoCHs)-suggest that PoCHs are judged as bad parents. Yet little work has tested whether people genuinely stigmatize PoCHs or wh...

Courts in seven U.S. states have removed children with “obesity” from parental custody until children could maintain “healthy weights.” These rulings—alongside qualitative reports from parents of children with higher-weight (PoCH)—suggest parents of PoCH are stigmatized. Yet little work tests whether social perceivers genuinely stigmatize PoCH, or...

Status is a universal feature of human sociality. A lesser-studied adaptive problem surrounding status is assessing who has which levels of status in a given group (e.g., identifying which people possess high status). Here, we integrate theory and methods from evolutionary social science, animal behavior, and social psychology, and we use an emotio...

Research on close relationships has tended to focus on the dyad (e.g., friends, romantic partners, rivals). Less attention has been paid to the myriad third parties who impact our social lives through their own relationships with our dyadic partners. What drives our feelings toward such third parties? A classic formalist theory, Balance Theory, sug...

New analyses related to Varnum, M. E. W., Krems, J. A., Morris, C., Wormley, A., & Grossmann, I. (2021). Why are song lyrics becoming simpler? a time series analysis of lyrical complexity in six decades of American popular music. PLOS ONE, 16(1), e0244576.

Relationships with genetic relatives have been extensively studied in the evolutionary social sciences, but affinal, i.e., in-laws, relationships have received much less attention. Yet, humans have extensive interactions with the kin of their mates, leading to many opportunities for cooperative and conflictual interactions with extended kinship net...

Overweight and obese (“heavyweight”) people devalue themselves because, it has been proposed, they are socially devalued. However, for women, social valuation depends not only on how much weight they carry but also on where on their bodies they carry it. Here, we investigated whether weight-based self-valuation and perceived social valuation simila...

Friendships are valuable social relationships that provide many psychological and health benefits. However, friendships can also be costly and exploitative. How do we ensure maximum benefits while reducing potential costs from friendships? One way is to have “rules” (heuristics for assessing value -- if a rule is broken, then the friendship provide...

Friends bolster health and happiness, with friend preferences directing us toward friends who can facilitate this. Intuition and research alike suggest people prefer friends to be kind and trustworthy and disfavor viciousness and indifference (and befriend the similar, familiar, nearby). Taking a target-specific approach, we predict and find people...

Negative stereotypes about atheists are widespread, robust, rooted in distrust, and linked to discrimination. Here, we examine whether social perceivers in the US might additionally hold any positive stereotypes about atheists (and corresponding negative stereotypes of the religious). Experiments 1 (N = 401) and 2 (N = 398, preregistered) used meth...

Friendships can help us solve a number of challenges, increasing our welfare and fitness. Across evolutionary time, some of the many challenges that friendships helped to solve may have differed between men and women. By considering the specific and potentially distinct recurrent problems men's and women's friendships helped them solve, we can deri...

Friendships provide material benefits, bolster health, and may help solve adaptive challenges. However, a recurrent obstacle to sustaining those friendships—and thus enjoying many friendship-mediated fitness benefits—is interference from other people. Friendship jealousy may be well-designed for helping both men and women meet the recurrent, adapti...

Objectives: Sexual Strategies Theory suggests people fall on a continuum between having short-term mating orientation (STMO) and long-term mating orientation. One way STMO individuals signal mating goals is via risky drinking. The current study therefore aims to investigate drinks per week (DPW) as a mediator between STMO and risky sexual behavior...

People with overweight and obesity devalue themselves, partially because they are socially devalued. However, for women, social valuation depends not only on how much weight they carry but where on their bodies they carry it. Here, we investigate whether weight-based self-valuation and perceived social valuation also depend on body shape. Study 1,...

Adverse childhood experiences (ACEs) may be an early life factor associated with adult weight stigma via biological (e.g., stress response), cognitive (e.g., self-criticism/deprecation), and/or emotional (e.g., shame) mechanisms. This pilot study investigated relationships between ACEs and internalized and experienced weight stigma in adult women w...

After half a century of debate and few empirical tests, there remains no consensus concerning why ovulation in human females is considered concealed. The predominant male investment hypothesis states that females were better able to obtain material investment from male partners across those females’ ovulatory cycles by concealing ovulation. We buil...

An article published in Current Directions a decade ago introduced the fundamental-motives framework and reviewed initial promising findings using this general approach. According to this framework, a recurring set of challenges and opportunities during human evolution gave rise to overarching motivational systems in the domains of self-protection,...

Heavier bodies—particularly female bodies—are stigmatized. Such fat stigma is pervasive, painful to experience, and may even facilitate weight gain, thereby perpetuating the weight-stigma cycle. Leveraging research on functionally distinct forms of fat (deposited on different parts of the body), we propose that body shape plays an important but lar...

Song lyrics are rich in meaning. In recent years, the lyrical content of popular songs has been used as an index of culture’s shifting norms, affect, and values. One particular, newly uncovered, trend is that lyrics of popular songs have become increasingly simple over time. Why might this be? Here, we test the idea that increasing lyrical simplici...

Heavier bodies—particularly female bodies—are stigmatized. Such fat stigma is pervasive, painful to experience, and may even facilitate weight gain, thereby perpetuating the obesity-stigma cycle. Leveraging research on functionally distinct forms of fat (deposited on different parts of the body), we propose that body shape plays an important but la...

Negative stereotypes about atheists are widespread, robust, rooted in distrust, and linked to discrimination. Here, we examine whether social perceivers in the US might additionally hold any positive stereotypes about atheists (and corresponding negative stereotypes of the religious). Experiments 1 (N = 401) and 2 (N = 398, preregistered) used meth...

(Accepted at Psychological Science) Although casual sex is increasingly socially acceptable, negative stereotypes toward women pursuing casual sex appear to remain pervasive. Specifically, a common trope in media (e.g., television, film) is that such women have low self-esteem. Despite robust work on prejudice against women who engage in casual sex...

Song lyrics are rich in meaning. In recent years, the lyrical content of popular songs has been used as an index of culture’s shifting norms, affect, and values. One particular, newly uncovered, trend is that lyrics of popular songs have become increasingly simple over time. Why might this be? Here, we test the idea that increasing lyrical simplici...

Relationships with genetic relatives have been extensively studied in the evolutionary social sciences, but affinal relationships have received much less attention, and virtually no work has examined both cooperation and conflict among affines from an evolutionary perspective. Yet humans have extensive interactions with the kin of their mates, i.e....

Friendships can foster happiness, health, and reproductive fitness. However, friendships end-even when we might not want them to. A primary reason for this is interference from third parties. Yet, little work has explored how people meet the challenge of maintaining friendships in the face of real or perceived threats from third parties, as when ou...

Friendships provide material benefits, bolster health, and may help solve adaptive challenges. However, a recurrent obstacle to sustaining those friendships—and thus enjoying many friendship-mediated fitness benefits—is interference from other people. Friendship jealousy may be well-designed for helping both men and women meet the recurrent, adapti...

The affordance-management approach conceptualizes stereotyping, stereotype content, prejudices, and discriminatory inclinations as interlinked cognitive, affective, and behavioral tools used to manage the social opportunities and threats afforded by other people. Presenting research from our labs, we show how the affordance management approach enha...

Which people are most likely to harbor prejudice toward atheists? Recent research suggests that perceptions of (non)religious individuals tend to track lifestyle (i.e., family and sexual) choices. We draw on this work, proposing that anti-atheist prejudice stems, in part, from the conflict that arises among competing mating strategies. Across four...

Which people are most likely to harbor prejudice toward atheists? Recent research suggests that perceptions of (non)religious individuals tend to track lifestyle (i.e., family and sexual) choices. We draw on this work, proposing that anti-atheist prejudice stems, in part, from the conflict that arises among competing mating strategies. Across four...

Although casual sex is increasingly socially acceptable, negative stereotypes toward women pursuing casual sex appear to remain pervasive. Specifically, a common trope in media (e.g., television, film) is that such women have low self-esteem. Despite robust work on prejudice against women who engage in casual sex, little empirical work investigates...

Friendships can foster happiness, health, and reproductive fitness. But friendships end—even when we might not want them to. A primary reason for this is interference from third parties. Yet little work has explored how people meet the challenge of maintaining friendships in the face of real or perceived threats from third parties, as when our frie...

Close friendships are associated with greater happiness and improved health; historically, they would likely have provided beneficial fitness outcomes. Yet each friendship requires one's finite time and resources to develop and maintain. Because people can maintain only so many close relationships, including friendships, at any one time, choosing w...

What motives do people prioritize in their social lives? Historically, social psychologists, especially those adopting an evolutionary perspective, have devoted a great deal of research attention to sexual attraction and romantic-partner choice (mate seeking). Research on long-term familial bonds (mate retention and kin care) has been less thorough...

Religion has often been conceptualized as a collection of beliefs, practices, and proscriptions that lift people’s thoughts and behaviors out of the metaphorical gutter of sex and selfishness toward lives full of meaning, contemplation, and community service. But religious beliefs and behaviors may serve selfish, sexual motivations in ways that are...

What motives do people prioritize in their social lives? Historically, social psychologists, especially those adopting an evolutionary perspective, have devoted a great deal of research attention to sexual attraction and romantic partner choice (mate-seeking). Research on long-term familial bonds (mate retention and kin care) has been less thorough...

How has the complexity of cultural products changed over time and what is responsible for these changes? A cultural compression hypothesis (CCH) suggests that changes in simplicity (vs. complexity) of cultural products is associated with shifts in the volume of cultural products, with greater within-domain volume of products facilitating evolution...

It is genuinely difficult to sustain a casual conversation that includes more than four speakers. Add a fifth speaker, and the conversation often quickly fissions into smaller groups. Termed ‘the dinner party problem,’ this four-person conversation size limit is believed to be caused by evolved cognitive constraints on human mentalizing capacities....

Some acts of human cooperation are not easily explained by traditional models of kinship or reciprocity. Fitness interdependence may provide a unifying conceptual framework, in which cooperation arises from the mutual dependence for survival or reproduction, as occurs among mates, risk-pooling partnerships and brothers-in-arms.

Religious people are more trusted than nonreligious people. Although most theorists attribute these perceptions to the beliefs of religious targets, religious individuals also differ in behavioral ways that might cue trust. We examined whether perceivers might trust religious targets more because they heuristically associate religion with slow life...

Although the effects of sexual selection on male mating competition and intrasexual aggression have been studied extensively for well over a century, female mating competition and intrasexual aggression have only begun to receive serious attention in recent decades. Here, we focus on one aspect of sexually selected competition in girls and women-ri...

Van Lange et al. argue that variations in climate explain cross-societal variations in violence. We suggest that any approach seeking to understand cross-cultural variation in human behavior via an ecological framework must consider a wider array of ecological variables, and we find that income inequality and sex ratio are better predictors than cl...

Conversations are ubiquitous and central elements of daily life. Yet a fundamental feature of conversation remains a mystery: It is genuinely difficult to maintain an everyday conversation with more than four speakers. Why? We introduce a “mentalizing explanation” for the conversation size constraint, which suggests that humans have a natural limit...

Van Lange, Rinderu, and Bushman argue that variations in climate explain cross-societal variations in violence. We suggest that any approach seeking to understand cross-cultural variation in human behavior via an ecological framework must consider a wider array of ecological variables, and we find that income inequality and sex ratio are better pre...

Hyperlink cinema is an emergent film genre that seeks to push the boundaries of the medium in order to mirror contemporary life in the globalized community. Films in the genre thus create an interacting network across space and time in such a way as to suggest that people's lives can intersect on scales that would not have been possible without mod...