Development of the infant's hand preference for visually directed reaching: Preliminary report of a longitudinal study

The development of hand preference in infancy was investigated longitudinally by using a visually-directed reaching task. Thirty-two infants, equally divided into groups of familial right- and left-handed boys and girls, were tested every 3 weeks from 24 to 39 weeks of age and once again at 52 weeks. Group trends for the development of hand preference were differentiated by familial handedness and sex of the infant. At all ages, test object position (to the infant's right or left) strongly influenced the hand used for reaching. Marked variability both between and within infants demonstrated an instability of early hand preference, an effect that could be appreciated fully only with a prospective longitudinal design. The results thus suggest that the development of hand preference for reaching is highly variable, discontinuous, and related to the interaction of sex and familial handedness.     

Sex differences in genetic and environmental influences on DSM-III-R attention-deficit/hyperactivity disorder

Approximately 5% of children are affected by attention-deficit/hyperactivity disorder (ADHD), and more boys are affected than girls. This study examined the magnitude of genetic and environmental influences on ADHD and several questions regarding sex differences in its prevalence and liability. The participants were 2,391 twin and sibling pairs from Australia, ages 3-18. ADHD symptoms in the general population were highly heritable (h2 = .85-.90), as were deviant ADHD scores in the selected population. The magnitude of familial influences was similar for boys and girls, although there were shared environmental influences on ADHD in girls but not boys and dominance genetic influences on ADHD in boys but not girls. Specific genetic and environmental influences were highly similar for boys and girls. Evidence supported the polygenic multiple threshold model rather than the constitutional variability model of sex differences in ADHD.     

Sex Differences in Referral Rates of Children with Gender Identity Disorder: Some Hypotheses

From 1978 through 1995, a sex ratio of 6.6:1 of boys to girls (N = 275) was observed for children referred to a specialty clinic for gender identity disorder. This article attempts to evaluate several hypotheses regarding the marked sex disparity in referral rates. The sexes did not differ on four demographic variables (age at referral, IQ, and parent's social class and marital status) and on five indices of general behavior problems on the Child Behavior Checklist; in addition, there was only equivocal evidence that boys with gender identity disorder had significantly poorer peer relations than girls with gender identity disorder. Although the percentage of boys and girls who met the complete DSM-III-R criteria for gender identity disorder was comparable, other measures of sex-typed behavior showed that the girls had more extreme cross-gender behavior than the boys. Coupled with external evidence that cross-gender behavior is less tolerated in boys than in girls by both peers and adults, it is concluded that social factors partly account for the sex difference in referral rates. Girls appear to require a higher threshold than boys for cross-gender behavior before they are referred for clinical assessment.     

Cognitive sex differences: speed and problem-solving strategies on computerized neuropsychological tasks

Skill, strategy, and laterality measures obtained through computerized neuropsychological tasks, a reaction time (RT) test, and a visuospatial problem-solving test, the Perceptual Maze Test, were analyzed in relation to sex and handedness of 56 high-school students. Boys were significantly faster than girls on most RT subtasks (including a response-inhibition task) and made more two-choice RT response errors for right-sided stimuli, which may be interpreted as resulting from a less cautious strategy. In maze performance, boys were superior to girls. An analysis of separate phases of the maze-solution process suggested that boys preferentially used an impulsive-global strategy. Girls, using a more reflective-sequential task-solving strategy, were significantly slower, without hitting more targets. Compared to all other groups, left-handed girls (strongly left-handed) had lower performance on maze tasks with no target information, particularly in left-sided solution pathways. Results were interpreted as reflecting differences in hemispheric competence and activation patterns between the sexes. Signs of a less differentiated lateralization and slight dysfunction of visuospatial skills in the left-handed girls were discussed.     

Preliminary examination of sex differences in depressive symptoms among adolescent psychiatric inpatients: the role of anxious symptoms and generalized negative affect.

Assessed the emerging view that generalized negative affect and anxious symptoms are important in understanding sex differences in depressive symptoms. Sixty-three adolescent psychiatric inpatients (32 boys, 31 girls), ages 12 to 16 (M = 13.87, SD = 1.36), completed measures of positive and negative affect and anxious and depressive symptoms. Results demonstrated, as predicted, that depressive and anxious symptoms were more highly associated in adolescent girls than boys. Furthermore, girls with depressive symptoms were more likely to have comorbid anxious symptoms than boys with depressive symptoms. Sex differences were not found for adolescents with specific depressive symptoms and specific anxious symptoms (i.e., the absence of comorbidity). Our findings supported the possibility that sex differences in pure forms of depression are overestimated and that comorbid internalizing conditions may be more prevalent in adolescent girls than boys.     

The influence of gender on occupational aspirations of kindergarten children

By updating and extending previous research on the effect of gender role socialization on occupational choices of children, this research found very sexstereotypical occupational preferences in a sample of 540 kindergarten children. The girls in the study selected occupations that averaged 87% female and the boys selected occupations averaging 84% male. The boys perceived a significantly wider range of vocational options than the girls. In a reversal condition, children were asked to pretend to be of the opposite sex. Most of the children selected occupations with sex ratios favoring their pretended sex; girls were slightly more stereotypic than boys. An unanticipated finding was the extremeness of reactions of the boys to the suggestion that they pretend to be girls. It is argued that current sex-role socialization fails to recognize the realities of the expanding participation of women in the paid labor force.     

Patterns of Adolescent Aggression and Victimization: Sex Differences and Correlates

This study identified heterogeneous patterns of peer and dating aggression and victimization among boys and girls and examined their relation to risk and protective correlates. Girls (n = 1648) and boys (n = 1420) in grades 8–10 completed surveys assessing 14 indicators of violence involvement. Latent class analyses indicated a four-class solution, though a test of measurement invariance indicated the nature of the classes differed by sex. Among boys and girls, three classes emerged: Uninvolved (45% of girls, 61% of boys), Peer Aggressor-Victims (23% of girls, 21% of boys), and Cross-Context Aggressor-Victims (CCAV) (12% of girls, 5% of boys). Those in the Peer Aggressor-Victims class were likely to report involvement in peer aggression only; however, girls in this class were likely to be involved only in moderate violence, whereas boys were likely to be involved in moderate and severe violence. Those in the CCAV class were likely to report involvement in all forms of violence except sexual and controlling aggression, which was likely only among boys. Among girls, but not boys, a Verbal Dating Aggressor-Victims class (21% of girls) emerged that was characterized by involvement in occasional verbal dating aggression only. Among boys, but not girls, a Cross-Context Physical Victims class (13% of boys) emerged that was characterized by being only a victim of moderate physical peer and dating violence. Unique and shared risk and protective factors distinguished class membership for girls and boys. Findings suggest the pathways leading to violence may differ by sex and result in different patterns of violence involvement.     

Preferences for ‘Gender‐typed’ Toys in Boys and Girls Aged 9 to 32 Months

Many studies have found that a majority of boys and girls prefer to play with toys that are typed to their own gender but there is still uncertainty about the age at which such sex differences first appear, and under what conditions. Applying a standardized research protocol and using a selection of gender‐typed toys, we observed the toy preferences of boys and girls engaged in independent play in UK nurseries, without the presence of a parent. The 101 boys and girls fell into three age groups: 9 to 17 months, when infants can first demonstrate toy preferences in independent play (N = 40); 18 to 23 months, when critical advances in gender knowledge occur (N = 29); and 24 to 32 months, when knowledge becomes further established (N = 32). Stereotypical toy preferences were found for boys and girls in each of the age groups, demonstrating that sex differences in toy preference appear early in development. Both boys and girls showed a trend for an increasing preference with age for toys stereotyped for boys. Theoretical implications of the findings are discussed with regard to biological predispositions, cognitive development and environmental influences on toy preference. Copyright © 2016 John Wiley & Sons, Ltd.     

Interests and Leadership among Adolescents

The purpose of this study was to ascertain whether there is a differential relationship in the socialization of children with respect to gender identification when responses of children were examined with respect to race and sex (N = 596 fifth and sixth grade boys and girls). Strong father preference was found to have no effect on the choice a boy will make when choosing between male and female peers, during preadolescence, while a strong mother preference by a girl is related to the sex of the peers she chooses. Preadolescent girls who identify with their mothers chose girls with whom to interact in a variety of activities more frequently than they chose boys. A greater proportion of girls preferred to engage in activities with their mothers than boys preferred to engage in activities with their fathers. No differences were observed between racial groups in terms of girls' choices involving peers. Black boys, however, preferred to engage in activities with opposite-sex rather than same-sex peers to a greater extent than white boys.     

Higher face recognition ability in girls: Magnified by own-sex and own-ethnicity bias

Earlier studies on adults have shown sex differences in face recognition. Women tend to recognise more faces of other women than men do, whereas there are no sex differences with regard to male faces. In order to test the generality of earlier findings and to examine potential reasons for the observed pattern of sex differences, two groups of Swedish 9-year-old children (n = 101 and n = 96) viewed faces of either Swedish or Bangladeshi children and adults for later recognition. Results showed that girls outperformed boys in recognition of female faces, irrespective of ethnicity and age of the faces. Boys and girls recognised Swedish male faces to an equal extent, whereas girls recognised more Bangladeshi male faces than boys did. These results indicate that three factors explain the magnitude of sex differences in face recognition: an overall female superior face recognition ability, the correspondence between the sex of viewer and the gender of the face, and prior knowledge of the ethnicity of the face.     

Sex differences in early verbal and non‐verbal cognitive development

The present study of over 3000 2‐year‐old twin pairs used a sex‐limitation model to examine genetic and environmental origins of sex differences in verbal and non‐verbal cognitive ability. Girls scored significantly higher on both measures (p<0.0001), although gender only accounted for approximately 3% of the variance in verbal ability and 1% of the variance in non‐verbal cognitive ability. For the verbal measure boys showed greater heritability than girls. Also the twin‐pair correlation is significantly lower for opposite‐sex twins than for non‐identical same‐sex twins. This indicates that individual differences in verbal ability include some sex‐specific factors. Non‐verbal cognitive ability did not differ in aetiology for boys and girls. We conclude that genetic and environmental influences differ for girls and boys for early verbal but not non‐verbal development.     

SEX ROLE SATISFACTION AMONG AUSTRALIAN CHILDREN: SOME SEX, AGE, AND CULTURAL GROUP COMPARISONS

Children's satisfaction with being a member of their own sex was explored within two Australian samples. In a national sample of 2,268 children, grades 1–6, trends were similar to those reported in the United States. Girls were less satisfied with their sex role than boys, and older girls were more dissatisfied than younger girls. The most frequent reason girls offered for dissatisfaction with their sex was restriction of sports opportunities. In a smaller sample of 9–11-year-olds (133 boys, 146 girls), chosen to include adequate representation of children of non-Anglo immigrants, it was found that while Anglo-Australian girls were less satisfied with their sex role than boys, non-Anglo girls were just as satisfied as the boys. The non-Anglo girls were no higher in global satisfaction with themselves or with their lives in general than other children. They were, however, less likely to offer self-definitions that included sports abilities and interests. While non-Anglo parents observed a stronger public/private division of labor in certain childcare activities, this difference was not associated with children's satisfaction with their sex role. However, across the entire sample, children's sex-role satisfaction was associated with parents' division of labor on two tasks on which cultural groups did not differ—disciplining and comforting.     

Children's sex-role preferences: Stronger among girls than boys

Criticisms were raised about methods used in previous studies which have led to the conclusion that, compared to boys, girls have weaker preferences for their own versus the opposite sex role. In addition, it was argued that if children's own conceptions of sex roles — rather than an a priori adult definition — were investigated, girls would prefer their conception of femininity more than boys would prefer their conception of masculinity. This argument rested on evidence that for children, masculine traits often meet with social disapproval. Results indicated that both boys and girls judged their own sex role as more desirable than the opposite sex role. Results were stronger for the girls; and girls judged traits they assigned to the feminine sex role to be, on the average, more desirable than boys judged traits they assigned to masculinity. The difference between present findings and previous findings in regard to children and adults was discussed.Dennis Quintana assisted with the initial selection of items for the questionnaires described below. Elizabeth Bates, Ph.D., offered helpful suggestions for rewriting an earlier draft of this paper.     

Preference for Sex of Child Among Primiparous Women

Primiparous American women (N = 140) were questioned during their third trimester concerning their choice of sex of offspring and their willingness to use sex preselection techniques (if available). Eighty-two women expressed no preference for sex of offspring; of the remaining 58, 33 chose girls and 25 chose boys. Of the 26 women who indicated they would have used preselection technology, 13 chose boys and 13 chose girls. Fifty-three percent of the sample indicated they would not have used preselection techniques; 29% were undecided. These results were at variance with earlier studies that indicated a consistent choice of male firstborns, especially in nonpregnant samples. The discrepancy is discussed in terms of a move from boy preference to no preference and a gradual weakening of societal bias against women.     

Personal and family factors as predictors of pupils' mathematics achievement

This study examined personal and family factors in prediction of mathematics achievement by Kuwaiti fourth graders (395 boys, 501 girls; M age=10.0 yr., SD=8.0 mo.). Personal variables included sex, total achievement, perception of parental involvement, pupil's attitude towards school, and mathematics achievement. Family variables included parental education and parental involvement, views of school, and income. The data had good fit with the suggested model. Analysis showed variables which had significant direct association with mathematics achievement were total achievement and sex. Parental education, pupil's sex, and attitude towards school had significant indirect associations with mathematical achievement. Associations were direct for boys and indirect for girls on mathematics achievement, so sex had minimal total effects on mathematics achievement.     

Sex differences in math performance: The role of children's approach to schoolwork

This research examined whether the tendency for girls to outperform boys in the classroom is due to differences in how girls and boys approach schoolwork. In 5th grade and then again in 7th grade, children (N=518) reported on how they approach schoolwork (i.e., achievement goals and classroom behavior), their learning strategies, and their self-efficacy in math; math grades and achievement test scores were also collected. Girls were more likely than boys to hold mastery over performance goals and to refrain from disruptive classroom behavior, which predicted girls' greater effortful learning over time. The sex difference in learning strategies accounted for girls' edge over boys in terms of grades. Girls did not do better on achievement tests, possibly because self-efficacy, for which there was also no sex difference, was the central predictor of performance on achievement tests.     

When Empathy Matters: The Role of Sex and Empathy in Close Friendships

Based on prior theory and research (Ciarrochi & Heaven, 2009; Eagly & Wood, 1999), we hypothesized that the link between empathy and friendship would be moderated by sex: Girls will nominate empathic boys as friends, whereas boys will not tend to nominate empathic girls. We collected measures of empathy, friendship social support, and close friendship nominations in grade 10 across 1,970 students in 16 schools (M_age = 15.70, SD = .44; males = 993, females = 977). Multilevel models revealed that boys high in cognitive empathy attracted an average of 1.8 more girl friendship nominations than did their low empathy counterparts, whereas empathic girls did not attract a greater number of opposite‐sex friends. In addition, the more friendship nominations a boy received from either boys or girls, the more they felt supported by their friends; the number of friendship nominations received by girls, in contrast, had no effect on their felt support by friends. Regardless of the quantity of friendship nominations, empathy was linked to more supportive friendships for both males and females. These results inform a contextual understanding of the role of empathy in selecting and maintaining friendships.     

Higher face recognition ability in girls: Magnified by own-sex and own-ethnicity bias

Earlier studies on adults have shown sex differences in face recognition. Women tend to recognise more faces of other women than men do, whereas there are no sex differences with regard to male faces. In order to test the generality of earlier findings and to examine potential reasons for the observed pattern of sex differences, two groups of Swedish 9-year-old children (n = 101 and n = 96) viewed faces of either Swedish or Bangladeshi children and adults for later recognition. Results showed that girls outperformed boys in recognition of female faces, irrespective of ethnicity and age of the faces. Boys and girls recognised Swedish male faces to an equal extent, whereas girls recognised more Bangladeshi male faces than boys did. These results indicate that three factors explain the magnitude of sex differences in face recognition: an overall female superior face recognition ability, the correspondence between the sex of viewer and the gender of the face, and prior knowledge of the ethnicity of the face.     

Self-reported suicidal behavior in Dutch secondary education students

From nearly 10,000 secondary education students in The Netherlands, aged 14-20, data were collected on the prevalence of suicide attempts and recent thoughts about suicide and death. In this sample, 3.3% of the girls and 1.3% of the boys indicated that they had attempted suicide. The youngest students already reported as many attempts as the eldest, which is remarkable. Differences between boys and girls and between various types of schools were not substantial. We also found that 5.2% of the girls and 2.2% of the boys currently had thoughts of suicide. Again, there was no substantial difference as regards sex, type of school, and age. There was, however, a (small) difference between boys and girls concerning thoughts of death--namely, 9.3% of the girls versus 4.8% of the boys.     

Perceptions of body image among Japanese and Croatian children of preschool age

This study examined the differences in current and ideal body size among 108 Japanese and 129 Croatian preschool children (M=4.9 yr.). Boys and girls in both samples showed similarities by selecting the figure representing their current body size. Significant sex differences were found in selection of an ideal figure in the Japanese sample but not in the Croatian group. Japanese girls showed greater preference for a thinner figure than boys. In selection of an ideal body size significant cultural differences were found only for boys: Japanese boys preferred thinner figures. Results relating to body discrepancy (Current minus Ideal figures) indicated that there were fewer satisfied Japanese girls than Croatian girls whereas for the boys, a significantly larger number of Japanese than Croatian boys wished to be heavier.