Jessica D Ayers

Boise State University | BSU · Department of Psychology

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...

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...

Human sociality is governed by two types of social norms: injunctive norms, which prescribe what people ought to do, and descriptive norms, which reflect what people actually do. The process by which these norms emerge and their causal influences on cooperative behavior over time are not well understood. Here, we study these questions through socia...

Given the importance of friendships during challenging times and the mixed associations between personality traits and disease-related behaviors, we investigated the correlations between personality traits and perceptions of friendships during the COVID-19 pandemic. Data were collected as part of a longitudinal investigation of the correlations bet...

After decades of research on the topic of reciprocity, there is still no consensus about the meaning of the term. Instead, there has been a proliferation of reciprocity terms with varied definitions, some of which overlap in ways that lead to confusion for scholars studying cooperation. In this paper, we provide a summary of 34 reciprocity terms an...

Sometimes people help one another expecting to be repaid, while at other times people help without an expectation of repayment. What might underlie this difference in expectations of repayment? We investigate this question in a nationally representative sample of US adults (N = 915), and find that people are more likely to expect repayment when nee...

The COVID-19 pandemic drastically changed the ways in which social interactions happened. This is particularly true for valued social relationships such as friendships. Friendships provide many physical and mental health benefits, including buffering against loneliness during the pandemic, so contact and interactions with friends may have become mo...

Human sociality is governed by two types of social norms: injunctive social norms, which prescribe what people ought to do, and descriptive social norms, which reflect what people actually do. These norms enable people to cooperate in the face of group-wide challenges. While previous experimental work has shown that people’s behavior is influenced...

Understanding how genetics influences human psychology is something that evolutionary sciences emphasize. However, the functions of complex genetic influences on behavior have been overlooked in favor of perspectives that posit unitary influences of genes on behavior. One such example is the belief that human growth, development, and behavior are i...

Background: COVID-19 was declared a global pandemic in March 2020. Resulting containment protocols altered the day-to-day lives of people around the globe, impacting typical physical activity patterns. Purpose: The purpose of this mixed-method study was to understand how physical activity changes occurred during the first few months of the COVID-19...

After decades of research on the topic of reciprocity, there is still no consensus about the meaning of the term. Instead, there has been a proliferation of reciprocity terms with varied definitions, some of which overlap in ways that lead to confusion for scholars studying cooperation. In this paper, we provide a summary of 34 reciprocity terms an...

Friendships provide social support and mental health benefits, yet the COVID-19 pandemic has limited interactions with friends. In August 2020, we asked participants (N = 634) about their friendships during the pandemic as part of a larger study. We found that younger people and people with higher subjective SES reported more negative effects on th...

Here, we identify a novel reason why women are often criticized and condemned for (allegedly) sexually permissive behavior due to their choice of clothing. Combining principles from coordinated condemnation and sexual economics theory, we developed a model of competition that helps explain this behavior. We hypothesized that women collectively cond...

Given the importance of friendships during challenging times and the mixed associations reported between personality traits and disease-related behaviors, we investigated the influence of personality traits on friendships during the COVID-19 pandemic and how both influenced risky behaviors. In November 2020, we asked participants about their reacti...

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...

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...

Background: Physical activity (PA) mitigated psychological distress during the initial weeks of the COVID-19 pandemic, yet not much is known about whether PA had effects on stress in subsequent months. We examined the relationship between change over time in COVID-related stress and self-reported change in PA between March and July 2020. Methods:...

Theoretical considerations and early empirical findings suggested facial width-to-height ratio (fWHR) may be relevant to person perception because it is associated with behavioral dispositions. More recent evidence failing to find fWHR-behavior links suggests that mismatch or byproduct hypotheses may be necessary to explain fWHR-based trait inferen...

Despite the effectiveness of face masks in reducing the spread of COVID-19, many people refused to wear them. Previous studies have shown how a variety of demographic and individual difference factors (e.g., political orientation, stress, perceived risk of infection) predict use of masks. However, people’s health protective behavior can vary depend...

There is no question that competition is part of life, but until recently researchers have not investigated women’s competition. A meta-analysis of 14 published effects with 61 effect sizes (N = 2,100) assessed the size of the effect of women’s competition. Since few studies have comprehensively assessed female intrasexual competition, competition...

What explains differences in attitudes towards wearing protective face masks to limit the spread of the SARS-CoV-2 virus? We investigated potential drivers of attitudes about mask wearing as part of a longitudinal study during the COVID-19 pandemic (N-participants = 711, N-countries = 36), focusing on people’s perceptions and feelings about seeing...

Here, we identify a novel reason why women are often criticized and condemned for (allegedly) sexually permissive behavior, such as their choice of dress. Combining principles from coordinated condemnation and sexual economics theory, we developed a model of competition that accounts for women’s competition in the absence of mating-relevant advanta...

Friendships are important for social support and mental health, yet social distancing during the COVID-19 pandemic have limited people’s ability to interact with their friends during this difficult time. In August of 2020, we asked participants about changes in their friendships as a result of the pandemic - including changes in the quality of frie...

Since the beginning of the COVID-19 pandemic, wearing protective facial masks has become a divisive issue, yet little is known about what drives differences in mask wearing across individuals. We surveyed 711 people around the world, asking about mask wearing and several other variables. We found that people who reported greater perceived risk of i...

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....

Need-based transfer systems pool risk among interdependent individuals. Such arrangements are bound by two simple rules: Ask for help only when in need and, if you are able, give help to others who ask. But there may be a temptation for individuals to break these rules for short-term personal profit. Here, we study one factor that may enforce hones...

Did the COVID-19 pandemic bring people together or push them apart? We asked an international sample (N = 1,006) about their inclinations to cooperate, perceptions of interdependence with others, and perceived risk of COVID-19 infection on fourteen different occasions from March 6, 2020 to August 22, 2020. We found that willingness to cooperate dec...

Fitness interdependence refers to the degree to which two or more organisms influence each other’s success in replicating their genes. We designed a new scale of perceived fitness interdependence that explicitly measures how individuals’ feelings and outcomes covary with the outcomes of specific partners (e.g., “When [target] succeeds, I feel good....

Previous research suggests that facial width-to-height ratio (fWHR) may be associated with behavioral tendencies and social judgments. Mounting evidence against behavioral links, however, has led some researchers to invoke evolutionary mismatch to explain fWHR-based inferences. To examine whether such an explanation is needed, we leveraged a large...

Smartphone use changes the landscape of social interactions, including introducing new social dilemmas to daily life. The challenge of putting down one's smartphone is an example of a classic coordination problem from game theory: the stag hunt game. In a stag hunt game, there are two possible coordination points, one that involves big payoffs for...

Need-based transfer systems function to pool risk. Such arrangements are bound by two simple rules: Ask for help only when in need and, if you are able, give help to others who ask. But there is a temptation for individuals to break these rules for short-term personal profit. Here, we study one factor that may enforce honesty in need-based transfer...

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.