A Role for the X Chromosome in Sex Differences in Variability in General Intelligence?

ABSTRACT— There is substantial evidence that males are more variable than females in general intelligence. In recent years, researchers have presented this as a reason that, although there is little, if any, mean sex difference in general intelligence, males tend to be overrepresented at both ends of its overall distribution. Part of the explanation could be the presence of genes on the X chromosome related both to syndromal disorders involving mental retardation and to population variation in general intelligence occurring normally. Genes on the X chromosome appear overrepresented among genes with known involvement in mental retardation, which is consistent with a model we developed of the population distribution of general intelligence as a mixture of two normal distributions. Using this model, we explored the expected ratios of males to females at various points in the distribution and estimated the proportion of variance in general intelligence potentially due to genes on the X chromosome. These estimates provide clues to the extent to which biologically based sex differences could be manifested in the environment as sex differences in displayed intellectual abilities. We discuss these observations in the context of sex differences in specific cognitive abilities and evolutionary theories of sexual selection.     

Sex Differences in Math-Intensive Fields

Despite impressive employment gains in many fields of science, women remain underrepresented in fields requiring intensive use of mathematics. Here we discuss three potential explanations for women's underrepresentation: (a) male-female mathematical and spatial ability gaps, (b) sex discrimination, and (c) sex differences in career preferences and lifestyle choices. Synthesizing findings from psychology, endocrinology, sociology, economics, and education leads to the conclusion that, among a combination of interrelated factors, preferences and choices-both freely made and constrained-are the most significant cause of women's underrepresentation.     

Impact of Exposure to Community Violence on Anxiety: A Longitudinal Study of Family Social Support as a Protective Factor for Urban Children

In a longitudinal study, we examined the relationship between exposure to community violence and anxiety, and the extent to which family social support moderated this relationship within a predominantly African American sample of 385 children in an urban public school system. Children reported notably lower anxiety levels compared to normative data for African American children. A high percentage reported witnessing a variety of violent acts. Cross-sectional results indicated that among girls exposure to violence was significantly correlated with total, physiological, and concentration anxiety. Among boys violence exposure was not associated with anxiety. Hierarchical regression analyses indicated that after controlling for gender, exposure to violence at Time 1 did not significantly predict changes in anxiety. A significant interaction was found for gender and exposure to violence on concentration anxiety; girls who reported higher initial violence exposure reported greater increases in subsequent concentration anxiety than boys. Whereas findings from our study did not support a moderating relationship of family social support on children's exposure to violence and anxiety, a strong negative relationship was found between anxiety and family support. Among children with initially low worry anxiety, those with low family social support showed greater increases in subsequent worry anxiety.     

Herrnstein''s syllogism: genetic and shared environmental influences on IQ, education, and income

Genotypes may influence the phenotypic associations among IQ, education, and income. To investigate this hypothesis, we believe that the appropriate methodology requires estimation of genetic and environmental influences using data able to separate these influences. The National Longitudinal Survey of Youth (NLSY) is a nationally representative sample that contains genetically-informative full- and half-siblings (28–35 years old in 1992; Ns=1943 full-siblings, 129 half-siblings). A biometric genetic model was fit that estimated the shared environmental and genetic variance components of IQ, years of education, and hourly income. The total heritabilities were 0.64 for IQ, 0.68 for education, and 0.42 for income. Heritabilities due to a common genetic factor were 0.35 for IQ, 0.52 for education, and 0.12 for income. Environmental influences due to a common shared environmental factor were 0.23 for IQ, 0.18 for education, and 0.08 for income. The model predicted a correlation of 0.63 between IQ and education and 0.34 between IQ and income. Sixty-eight percent of the former and 59% of the latter was genetically mediated; the remainder was mediated by common shared environment. These findings suggest that social inequality in the United States has its origin in both genetically-based traits and in different environmental backgrounds.     

Profiles of psychological well‐being in a sample of Australian university students

The present study identified psychological well‐being profiles in a sample of Australian university students (N = 207, Mean age = 30.16 years; SD = 11.90). Respondents completed two measures: Ryff's (1989) Psychological Well‐Being (PWB) scale and Lovibond and Lovibond's (2002) Depression, Anxiety and Stress Scales‐21 (DASS‐21) assessing their levels of PWB and depression. Latent profile analysis was applied to six indices of positive functioning derived from PWB scale: self‐acceptance, purpose in life, environmental mastery, positive relations with others, personal growth and autonomy. An optimal 5‐profile solution, reflecting significant incremental shifts from very low to very high PWB, was interpreted. As predicted, profile membership distinguished participants on depression. Importantly, profiles indicating moderate to very high PWB, particularly with the presence of above average autonomy, reported significantly lower levels of depression. Our results suggest prevention of, and treatment efficacy for, mental health problems may be improved by incorporating strategies that address positive functioning attributes, particularly associated with a sense of autonomy.     

Simulating murder: the aversion to harmful action

Diverse lines of evidence point to a basic human aversion to physically harming others. First, we demonstrate that unwillingness to endorse harm in a moral dilemma is predicted by individual differences in aversive reactivity, as indexed by peripheral vasoconstriction. Next, we tested the specific factors that elicit the aversive response to harm. Participants performed actions such as discharging a fake gun into the face of the experimenter, fully informed that the actions were pretend and harmless. These simulated harmful actions increased peripheral vasoconstriction significantly more than did witnessing pretend harmful actions or to performing metabolically matched nonharmful actions. This suggests that the aversion to harmful actions extends beyond empathic concern for victim harm. Together, these studies demonstrate a link between the body and moral decision-making processes.     

The Unique and Interactive Contributions of Peer Victimization and Teacher-Child Relationships to Children’s School Adjustment

The present study tested whether a close relationship with the teacher would reduce, or a conflictual relationship would amplify, links between peer victimization and school maladjustment. Data on 352 3rd- and 4th-grade children (166 boys; 186 girls) were collected over a two-year period. Teachers provided data on their relationships with students and students’ academic performance. Children completed measures assessing peer victimization and school liking. Latent growth curve analyses revealed that at high levels of peer victimization declines in school liking were reduced when student shared a close, low conflict, relationship with their teacher. Furthermore, a combination of peer victimization and poor teacher-child relationship quality predicted trajectories of sustained, low academic performance. These findings highlight the benefits of a close relationship with the teacher for victimized children and the cumulative impact stress within peer- and teacher-relationships can have on students.     

Feminism and Evolutionary Psychology: Moving Forward

The Special Issue on feminism and evolutionary psychology published by Sex Roles (Smith and Konik 2011) has elicited responses that advance understanding of the debate between evolutionary psychology and feminist perspectives concerning the origins of similarities and differences in the behavior of women and men (Smith and Konik 2013). The further challenges to evolutionary psychology mounted in these responses suggest that the Special Issue has intensified the debate more that it has resolved it. Moving forward requires that feminist psychologists not only add to the considerable body of empirical evidence that challenges evolutionary psychology but also produce alternative evolutionary theories that transcend the nature-nurture controversy that underlies the current debate. To this end, we refer readers to our biosocial constructionist theory in which culture and biology are intertwined in both distal evolutionary processes that shaped human psychology and proximal mechanisms that underlie differences and similarities in male and female behavior (Wood and Eagly 2012).     

Factors predicting the use of technology: findings from the Center for Research and Education on Aging and Technology Enhancement (CREATE)

The successful adoption of technology is becoming increasingly important to functional independence. The present article reports findings from the Center for Research and Education on Aging and Technology Enhancement (CREATE) on the use of technology among community-dwelling adults. The sample included 1,204 individuals ranging in age from 18-91 years. All participants completed a battery that included measures of demographic characteristics, self-rated health, experience with technology, attitudes toward computers, and component cognitive abilities. Findings indicate that the older adults were less likely than younger adults to use technology in general, computers, and the World Wide Web. The results also indicate that computer anxiety, fluid intelligence, and crystallized intelligence were important predictors of the use of technology. The relationship between age and adoption of technology was mediated by cognitive abilities, computer self-efficacy, and computer anxiety. These findings are discussed in terms of training strategies to promote technology adoption.