Threat perception and behavioral reactivity in response to an acute stressor in infant rhesus macaques.

Attentional bias to threat is an adaptive response to the presence of threat and danger in the environment (Haselton et al., 2009; Pollak, 2008). Attentional bias to threat is present in both human and nonhuman primates (e.

The power of prompts: Encouraging children to think about fairness promotes the costly rejection of unfairness.

Children in the United States have an early-emerging understanding that resources should be divided fairly among agents, yet their behavior does not begin to reflect this understanding until later in development. Why does this gap between knowledge and behavior exist, and how can we close it? Here, we tested the role of explicit prompts in closing the gap, asking whether prompting 4- to 9-year-olds to make fair decisions would promote the costly rejection of unfairness in the Inequity Game. Children were presented with either advantageous (more for actor, less for recipient) or disadvantageous (less for actor, more for recipient) allocations and assigned to one of three experimental conditions: Fairness Prompt, Autonomous Prompt, or Baseline.

The development of social essentialist reasoning in Iran: Insight into biological perception, cultural input, and motivational factors.

People express essentialist beliefs about social categories from an early age, but essentialist beliefs about specific social categories vary over development and in different contexts. Adapting two paradigms used with Western samples to measure social essentialism, we examined the development of essentialist beliefs about seven social categories (gender, race, nationality, religion, socioeconomic status, ethnicity, and team fan bases) among 5- to 10-year-old children ( = 88) and adults ( = 273) in Iran, a population that is underrepresented in psychology research. Focusing on natural-kind reasoning, we investigated the relative contribution of biological perception of social categories as well as cultural and motivational factors in the development of essentialist beliefs about these categories.

Beliefs about social mobility in young American children.

Although actual experiences of upward social mobility are historically low, many adolescents and adults express a belief in social mobility (e.g., that social status can change).

Automatic encoding across social categories in American children and adults.

Many caregivers wonder when to talk to children about social inequality and racism, often expressing the belief that children do not pay attention to race or inequity. Here, across 5-9-year-old American children ( = 159, = 7.44; 51.

Do American children automatically encode cues to wealth?

As adults, we readily notice markers of social status and wealth and draw conclusions about individuals based on these cues. Do children do the same? Using a "Who Said What?" task across 5- to 9-year-old American children (n = 159; M = 7.44 years; 51.

Early perceptions of COVID-19 intensity and anti-Asian prejudice among White Americans.

Anecdotal reports suggested an uptick in anti-Asian prejudice corresponding with the initial outbreak of the COVID-19 pandemic. Examining responses from White U.S.

Boys and girls, men and women: Do children take stimulus age into account when expressing gender stereotypes?

Gender and age are salient social categories from early in development. However, whether children's beliefs about gender and age intersect, such that gender stereotypes might be expressed differently when asked about children (compared to adults) has not been investigated. Here, in a preregistered study ( = 297), we examined if young children (3.

Why do children show racial biases in their resource allocation decisions?

Young children often prefer people high in status and with access to resources. Children also favor fairness and equality, especially when it comes to sharing. Two studies examined how children (N = 185; age range = 4.

Female ornaments: is red skin color attractive to males and related to condition in rhesus macaques?

Sexual selection produces extravagant male traits, such as colorful ornaments, via female mate choice. More rarely, in mating systems in which males allocate mating effort between multiple females, female ornaments may evolve via male mate choice. Females of many anthropoid primates exhibit ornaments that indicate intraindividual cyclical fertility, but which have also been proposed to function as interindividual quality signals.

Higher early life mortality with lower infant body mass in a free-ranging primate.

Traits that reflect the amount of energy allocated to offspring by mothers, such as infant body mass, are predicted to have long-lasting effects on offspring fitness. In very long-lived species, such as anthropoid primates, where long-lasting and obligate parental care is required for successful recruitment of offspring, there are few studies on the fitness implications of low body mass among infants. Using body mass data collected from 253 free-ranging rhesus macaque Macaca mulatta infants on Cayo Santiago, Puerto Rico, we examined if lower infant body mass predicts lower chance of survival through to reproductive maturation (4th year of life).

Children's use of race and gender as cues to social status.

Social hierarchies are ubiquitous and determine a range of developmental outcomes, yet little is known about when children develop beliefs about status hierarchies in their communities. The present studies (3.5-6.

Does essentialism lead to racial prejudice? It is not so Black and White.

Over half a century ago, psychologists hypothesized that social essentialism, an intuitive theory comprising the beliefs that social categories reflect naturally occurring distinctions and that category members share an underlying and fundamental essence, lays the foundation for prejudice. In the intervening decades, research has shown that although essentialism sometimes leads to prejudicial beliefs, attitudes, and behaviors, it does not always, sometimes even leading to decreased prejudice toward stigmatized groups. The relation between essentialism and prejudice is clearly complex, but this review proposes four questions that will help clarify how and when essentialism leads to prejudice: (1) What precisely is essentialism and how might a more nuanced understanding of its components and structure shed light on the mechanisms by which essentialist beliefs contribute to prejudice?; (2) Do essentialist beliefs orient group-based prejudice toward out-groups or toward stigmatized groups, and what are the consequences of essentialist beliefs among those with minoritized identities?; (3) Do essentialist beliefs engender group-based prejudice directly, or must essentialist beliefs interact with additional information or belief systems to lead to negative consequences?; and (4) Do essentialist beliefs lay a foundation for group-based prejudice to develop, or is essentialism strategically invoked to justify existing prejudice? By posing these questions, describing what is currently known about each, and proposing future lines of inquiry that focus on the importance of including participants from a diverse set of backgrounds and across developmental periods, this review aims to stimulate research studies best designed to fill the gaps in our knowledge.

Adaptive developmental plasticity in rhesus macaques: the serotonin transporter gene interacts with maternal care to affect juvenile social behaviour.

Research has increasingly highlighted the role that developmental plasticity-the ability of a particular genotype to produce variable phenotypes in response to different early environments-plays as an adaptive mechanism. One of the most widely studied genetic contributors to developmental plasticity in humans and rhesus macaques is a serotonin transporter gene-linked polymorphic region (5-HTTLPR), which determines transcriptional efficiency of the serotonin transporter gene and modifies the availability of synaptic serotonin in these species. A majority of studies to date have shown that carriers of a loss-of-function variant of the 5-HTTLPR, the short (s) allele, develop a stress-reactive phenotype in response to adverse early environments compared with long (l) allele homozygotes, leading to the prevalent conceptualization of the s-allele as a vulnerability allele.

Essentialism promotes racial prejudice by increasing endorsement of social hierarchies.

Why do essentialist beliefs promote prejudice? We proposed that essentialist beliefs increase prejudice toward Black people because they imply that existing social hierarchies reflect a naturally occurring structure. We tested this hypothesis in three studies ( = 621). Study 1 revealed that racial essentialism was associated with increased prejudice toward Blacks among both White and Black adult participants, suggesting that essentialism relates to prejudice according to social hierarchy rather than only to group membership.

The Nature and Consequences of Essentialist Beliefs About Race in Early Childhood.

It is widely believed that race divides the world into biologically distinct kinds of people-an essentialist belief inconsistent with reality. Essentialist views of race have been described as early emerging, but this study found that young children (n = 203, M  = 5.45) hold only the more limited belief that the physical feature of skin color is inherited and stable.

Vigilance for threat accounts for inter-individual variation in physiological responses to adversity in rhesus macaques: A cognition × environment approach.

Early life adversity (ELA) can lead to poor health later in life. However, there is significant variation in outcomes, with some individuals displaying resilience even in the face of adversity. Using longitudinal data collected from free-ranging rhesus macaques between birth and 3 years, we examined whether individual variation in vigilance for threat, an early emerging attentional bias, can account for variation in long-term outcomes between individuals reared in similar environments.

The development and developmental consequences of social essentialism.

People often view certain ways of classifying people (e.g., by gender, race, or ethnicity) as reflecting real distinctions found in nature.

Effects of early life adversity on cortisol/salivary alpha-amylase symmetry in free-ranging juvenile rhesus macaques.

Early life adversity (ELA) affects physiological and behavioral development. One key component is the relationship between the developing Hypothalamic-Pituitary-Adrenal (HPA) axis and the Sympathetic Nervous System (SNS). Recent studies suggest a relationship between early life adversity and asymmetry in cortisol (a measure of HPA activation) and salivary alpha-amylase (sAA: a correlate of SNS activation) responses to stress among human children, but to our knowledge there have been no comparable studies in nonhumans.

Oxidative stress as an indicator of the costs of reproduction among free-ranging rhesus macaques.

Sex differences in longevity may reflect sex-specific costs of intra-sexual competition and reproductive effort. As male rhesus macaques experience greater intrasexual competition and die younger, we predicted that males would experience greater oxidative stress than females and that oxidative stress would reflect sex-specific measures of reproductive effort. Males, relative to females, had higher concentrations of 8-OHdG and malondialdehyde, which are markers of DNA oxidative damage and lipid peroxidation, respectively.

Physiological and behavioural responses to weaning conflict in free-ranging primate infants.

Weaning, characterized by maternal reduction of resources, is both psychologically and energetically stressful to mammalian offspring. Despite the importance of physiology in this process, previous studies have reported only indirect measures of weaning stress from infants, because of the difficulties of collecting physiological measures from free-ranging mammalian infants. Here we present some of the first data on the relationship between weaning and energetic and psychological stress in infant mammals.

Early experience affects the strength of vigilance for threat in rhesus monkey infants.

Both human and nonhuman primates exhibit a cognitive bias to social threat, but little is known about how this bias develops. We investigated the development of threat bias in free-ranging infant rhesus macaques (Macaca mulatta) at 3 months (n = 45) and 9 months (n = 46) of age. Three-month-olds did not display bias, but 9-month-olds exhibited increased maintenance of attention to threatening social stimuli.

Variance-sensitive choice in lemurs: constancy trumps quantity.

Numerous studies have demonstrated that animals' tolerance for risk when foraging can be affected by changes in metabolic state. Specifically, animals on a negative energy budget increase their preferences for risk, while animals on a positive energy budget are typically risk-averse. The malleability of these preferences may be evolutionarily advantageous, and important for maximizing chances of survival during brief periods of energetic stress.

Mu-opioid receptor (OPRM1) variation, oxytocin levels and maternal attachment in free-ranging rhesus macaques Macaca mulatta.

Understanding the genetic and neuroendocrine basis of the mother-infant bond is critical to understanding mammalian affiliation and attachment. Functionally similar nonsynonymous mu-opioid receptor (OPRM1) SNPs have arisen and been maintained in humans (A118G) and rhesus macaques Macaca mulatta (C77G). In rhesus macaques, variation in OPRM1 predicts individual differences in infant affiliation for mothers.