Sex differences in children's toy preferences: A systematic review, meta-regression, and meta-analysis

The association between 2D:4D digit ratio and sex-typed play in children with and without siblings

The 2D:4D digit ratio is commonly used as a surrogate possibly reflecting prenatal testosterone levels. Indirect evidence comes from studies investigating the association between 2D:4D and human characteristics that likely relate to prenatal testosterone. In children, sex-typed play reveals large sex differences early in development and an influence of prenatal testosterone is likely. Findings on the association between 2D:4D and children's sex-typed play are heterogeneous and other influences on the development of sex-typed play have been suggested, most of all social influences like siblings, their sex and birth order. The current study examined the association between right and left 2D:4D, a proposed surrogate for prenatal testosterone exposure, which was assessed in right and left hands of N = 505 6-month-old children, and sex-typed play behavior, which was evaluated 3.5 years later using the Pre-School Activities Inventory (PSAI), and the influence of siblings. To capture differential effects of siblings' sex and birth order, dummy-coded variables were used reflecting having no siblings as well as older or younger sisters or brothers. Multiple regression models were used to investigate the association between PSAI scores and sex, right and left 2D:4D, being a singleton as well as having an older or younger sister or brother. It was shown that sex and having an older brother were significant predictors for sex-typed play. Effects were further disentangled by conducting separate regression analyses in boys and girls. In boys, a significant association between PSAI scores and having an older brother was revealed, in girls, no significant associations were found. Results are discussed highlighting the non-significant association between 2D:4D and children's sex-typed play, which weakens the applicability of 2D:4D as a surrogate reflecting influences of prenatal T. Further, the importance of social factors like siblings on children's sex-typed play is discussed.

Mothers' and fathers' neural responses toward gender-stereotype violations by their own children

Gender stereotypes facilitate people's processing of social information by providing assumptions about expected behaviors and preferences. When gendered expectations are violated, people often respond negatively, both on a behavioral and neural level. Little is known about the impact of family kinship on the behavioral and neural reactions to gender-stereotype violations. Therefore, we examined whether parents show different responses when gender stereotypes are violated by their own children vs unknown children. The sample comprised 74 Dutch families with a father (Mage = 37.54), mother (Mage = 35.83), son, and daughter aged 3-6 years. Electroencephalography measurements were obtained while parents viewed pictures of their own and unknown children paired with toy or problem behavior words that violated or confirmed gender stereotypes. In half of the trials, parents evaluated the appropriateness of toy-gender and behavior-gender combinations. Parents showed stronger late positive potential amplitudes toward gender stereotype-violating behaviors by own children compared to unknown children. Moreover, parents' P1 responses toward gender stereotype-violating child behaviors were stronger for boys than for girls and for parents who evaluated gender-stereotype violations as less appropriate than gender-stereotype confirmations. These findings indicated that gender-stereotype violations by parents' own children are particularly salient and viewed as less appropriate than gender-stereotype confirmations.

Prenatal androgen exposure and sex-typical play behaviour: A meta-analysis of classic congenital adrenal hyperplasia studies

Thousands of non-human mammal experiments have demonstrated that early androgen exposure exerts long-lasting effects on neurobehavioural sexual differentiation. In humans, females with classic congenital adrenal hyperplasia (CAH) are exposed to unusually high concentrations of androgens prenatally, whereas prenatal concentrations of androgens in males with CAH are largely normal. The current meta-analysis included 20 independent samples and employed multi-level meta-analytic models. Consistently across all 7 male-typical and female-typical play outcomes, in the expected directions, the present study found significant and large average differences between control males and control females (gs = 0.83-2.78) as well as between females with CAH and control females (gs = 0.95-1.08), but differences between males with CAH and control males were mostly negligible and were non-significant for 6 of the 7 outcomes (gs = 0.04-0.27). These meta-analytic findings suggest that prenatal androgen exposure masculinises and defeminises play behaviour in humans. Broader implications in relation to sex chromosomes, brain development, oestrogens, socio-cognitive influences, other aspects of sex-related behavioural development, and gender nonconformity are discussed.

Handedness as a major determinant of lateral bias in human functional cradling

Studies examining infant cradling have almost uniformly concluded with a general human left-side bias for cradling, indicating that people prefer to hold an infant to the left of their body. Explanations for the notion of the left-side cradling bias have traditionally been searched for in a variety of factors, for example, in terms of maternal heartbeat, genetic factors, in the form of an ear asymmetry where auditory information is perceived faster through the left ear, as a result of a right hemispheric functional specialization for perception of emotions and faces, and in identifying a motor bias of the infant, such as the tendency of newborn infants to lie with the face to the right when placed supine. Interestingly, handedness is generally considered an inadequate explanation for the lateralized cradling bias, despite it being an intuitively plausible one. In this brief review, I put forward the cradler's handedness as the most convincing and elegant determinant of the cradling bias. This explanation is consistent with a developmental cascades' framework where the cradling bias can be understood as the result of a multitude of factors across a range of levels and systems.

Monkeys do not show sex differences in toy preferences through their individual choices

BACKGROUND

As interest in evaluating sex differences in nonhuman animals grows, the finding that male and female monkeys have toy preferences that differ, and that parallel those documented in human children, has garnered significant attention and is leveraged as an argument in favor of a biological contribution for human sex differences. To date, however, only two studies have investigated sex differences in monkeys' toy preferences, both documenting that males prefer toys considered to be "masculine" (such as vehicles) and females prefer toys considered to be "feminine" (such as dolls). Monkeys in these studies were tested in their social groups, making it hard to determine if the sex differences reported reflect actual individual preferences or result from social dynamics present at the time of testing.

METHOD

Here, we assessed the preferences of 14 rhesus macaques (N = 7 males; N = 7 females) who were singly tested in a choice test with a variety of toys characterized as masculine (hard non-zoomorphic wheeled toys), feminine (zoomorphic soft toys), neutral (hard non-zoomorphic toys) and ambiguous (zoomorphic or plush vehicles) based on criteria from previous studies.

RESULTS

Males and females showed similar preferences for neutral and "masculine" toys and preferred them (i.e., were more likely to interact with them) to "feminine" and sex-ambiguous toys. When they interacted with the toys, both males and females interacted more with neutral than with "masculine" toys. Females, but not males, interacted more with neutral and "masculine" toys than with "feminine" toys. The highest frequency of interaction for any single toy for the male monkeys was with the doll-standing is stark contrast to previous findings.

CONCLUSIONS

Our results contrast greatly with the previous study in rhesus monkeys, as well as findings in human children, suggesting that the previously documented sex differences are likely context dependent, and question the existence of a strong biological basis to sex differences in toy preferences.

Cross-Cultural Sex/Gender Differences in Produced Word Content Before the Age of 3 Years

Does sex/gender matter for language acquisition? Small advantages in vocabulary size for females are well documented. In this study, however, we found that children's early vocabulary composition was a significantly better predictor of sex/gender than their vocabulary size. We conducted classification analysis on word-production data from children (12-36 months old, n = 39,553) acquiring 26 different languages. Children's sex/gender was classified at above-chance levels in 22 of 26 languages. Classification accuracy was significantly higher than for models based on vocabulary size and increased as a function of sample size. Boys produced more words for vehicles and outdoor scenes, whereas girls produced more words for clothing and body parts. Classification accuracy also increased as a function of age and peaked at 30 months, reaching accuracy levels observed in studies of adult word use. These differences in vocabulary are indicative of differences in the lifeworld of children and may themselves cause further differences in development.

Gendered play behaviours in autistic and non-autistic children: A population-based cohort study

LAY ABSTRACT

Non-autistic children tend to show gendered patterns of play behaviours - boys are more likely to play with 'masculine' toys, and girls are more likely to play with 'feminine' toys. However, little is known about whether autistic children follow these patterns as well. We looked at the masculinity and femininity of autistic and non-autistic children's play behaviours at multiple time points. Parents reported their children's play behaviours at ages 30, 42 and 57 months, and children reported their own play behaviours at 8 years old. We found no difference between autistic and non-autistic girls, who both showed more feminine play behaviours as they got older. Autistic boys' play behaviours were reported as less masculine than non-autistic boys at 42 and 57 months, and at 8 years old. We also found that non-autistic boys' play tended to become more masculine as they got older, but this was not the case for autistic boys. Our findings suggest that differences in autistic and non-autistic boys' play behaviours may develop at around 42 months old.

Relation between Demographics and Physical Activity among Preschoolers Attending Head Start

Limited empirical evidence is available about preschoolers' sedentary behavior (SB) and physical activity (PA) patterns in Head Start programs, we explored (a) preschoolers' SB and PA patterns (ranging from SB to light-moderate-vigorous physical activity [LMVPA]) and (b) their relationships with sociodemographic factors, weight status, and motor development. Participants included 216 preschoolers (M age = 4.32 ± 0.63; girls 56.5%) from six Head Start centers in an urban area in the southwestern region of the United States, assessing Actical® activity monitor-based PA, weight status, and motor development. The findings revealed preschoolers who were female, Hispanic/Latinx, with an at risk weight level, and/or in the below average motor development group tended to engage in less MVPA/LMVPA and also had higher SB patterns while participating in the Head Start program (p < 0.05-0.001, d ranged from 0.23 to 0.62). Head Start stakeholders (e.g., policymakers, leaders, curriculum coordinators, health professionals, and teachers) need to acknowledge the PA and health disparities, and intervene in underserved preschoolers' health-promoting behaviors.

Free time, gender and the pandemic: An exploration of children's daily routines in the times of COVID-19 in Chile

This article discusses the differentiation by gender displayed by children between 8 and 12 years old on how they used their free time during the COVID-19 pandemic in Chile. This study had a qualitative approach, where 43 in-depth interviews were conducted with children from three different regions of the country, using participatory photo-elicitation as the central tool. The main results of the study show a configuration of free time based on gender stereotypes, showing that boys are the ones who most adhere to such stereotypes, triggering a crisis in the identity construction of masculinities during childhood. The study also suggests that socioeconomic and territorial differences between children configures different experiences of the use of free time.

Did Children Interact With Their Personified Objects During the COVID-19 Pandemic?

Although previous studies revealed the characteristics of children with imaginary companions, the characteristics of children alone could not explain why some children create and interact with imaginary companions. The current cross-sectional study examined the impact of the situational factors, decreased opportunities to meet and play with real playmate due to the COVID-19 pandemic, on the prevalence of imaginary companions. Five hundred sixty caregivers of children aged 2-9 years (half of them were girls) were asked whether their children currently had imaginary companions (personified objects and invisible friends) before (September 2019) and during the pandemic (April 2020). The logistic regression model showed that only the prevalence of personified objects increased during the pandemic, OR = 2.01, 95%CI [1.34, 3.00], even when potential variables were controlled. The results suggest that children more frequently played with their personified objects during the pandemic compared to before the pandemic.

Prenatal testosterone and sexually differentiated childhood play preferences: a meta-analysis of amniotic fluid studies

Sexually differentiated behaviour appears to emerge from a complex interaction of biological and socio-cultural factors, with prenatal exposure to steroid hormones such as testosterone thought to play a key role. Due to large sex differences being present from a very early age, much research has focussed on the influence these hormones may have on play preferences during childhood. We present an overview of the literature and a random-effects meta-analysis linking amniotic testosterone with sexually differentiated play preferences (k = 9, n = 493). The overall effect size estimate was in the theory-consistent direction (i.e., with higher levels of testosterone associated with more male-typical play preferences), though not statistically significant (r = 0.082, p = 0.274). However, after three hypothesised missing studies were imputed via the trim and fill procedure, a significant correlation emerged (r = 0.166, p = 0.014). Nevertheless, one sample was observed to exert a particularly large influence on the outcome of the analysis. Notably this was the second biggest sample and related to the largest effect size estimate. Though far from conclusive, the overall findings are consistent with the idea that individual differences in prenatal testosterone within the typical range predict sexually differentiated play preferences in early life. However, these effects may be small in magnitude and appear to vary considerably across studies.

Culture influences the development of children's gender-related peer preferences: Evidence from China and Thailand

Current understanding of how culture relates to the development of children's gender-related peer preferences is limited. To investigate the role of societal acceptance of gender nonconformity, this study compared children from China and Thailand. Unlike China and other cultures where the conceptualization of gender as binary is broadly accepted, individuals who identify as a nonbinary "third" sex/gender have been highly visible and tolerated in Thai society for at least several decades. Chinese and Thai 4- to 9-year-olds (N = 458) viewed vignettes of four hypothetical peers who varied on gender (i.e., boy vs. girl) and gender-typed toy play behavior (i.e., masculine vs. feminine), and were asked to give a friendship preference rating for each peer. Chinese, compared with Thai, children evidenced gender-related peer preferences that emerged earlier, remained more stable across age groups, and were relatively more biased against gender-nonconforming behavior. The only cultural similarity was in children's preference for peers who were of the same gender and/or displayed same-gender-typed behavior. Thus, while preference for peers who are of the same gender and/or display same-gender-typed behavior is common among children across cultures, the developmental onset and course of these preferences vary by culture. Moreover, societal acceptance of gender nonconformity might be key to limiting children's bias against gender-nonconforming peers.

The Contribution of Peer Values to Children's Values and Behavior

Personal values have a key role in determining people’s perceptions, judgments, and behaviors. Only a handful of studies examined determinants of children’s values outside the family. We used longitudinal data on children’s values from 15,008 children in Grades 3 to 9, and homeroom teachers’ reports about the behaviors of 3,476 of these children. As predicted, peers’ values were positively correlated with the strengthening of children’s corresponding values. Moreover, with the exception of self-transcendence values, peer values had an indirect effect on corresponding child behavior, through children’s self-endorsed values. Girl peers had stronger effects on both girls’ and boys’ values. In addition, we found some evidence for stronger relationships between peer and children’s values among the older children, in particular among boys. These latter effects were even more prominent in an extended sample that included data from first and second graders. We discuss the theoretical and practical implications of our findings.

A Dynamic Systems Framework for Gender/Sex Development: From Sensory Input in Infancy to Subjective Certainty in Toddlerhood

From birth to 15 months infants and caregivers form a fundamentally intersubjective, dyadic unit within which the infant's ability to recognize gender/sex in the world develops. Between about 18 and 36 months the infant accumulates an increasingly clear and subjective sense of self as female or male. We know little about how the precursors to gender/sex identity form during the intersubjective period, nor how they transform into an independent sense of self by 3 years of age. In this Theory and Hypothesis article I offer a general framework for thinking about this problem. I propose that through repetition and patterning, the dyadic interactions in which infants and caregivers engage imbue the infant with an embodied, i.e., sensori-motor understanding of gender/sex. During this developmental period (which I label Phase 1) gender/sex is primarily an intersubjective project. From 15 to 18 months (which I label Phase 2) there are few reports of newly appearing gender/sex behavioral differences, and I hypothesize that this absence reflects a period of developmental instability during which there is a transition from gender/sex as primarily inter-subjective to gender/sex as primarily subjective. Beginning at 18 months (i.e., the start of Phase 3), a toddler's subjective sense of self as having a gender/sex emerges, and it solidifies by 3 years of age. I propose a dynamic systems perspective to track how infants first assimilate gender/sex information during the intersubjective period (birth to 15 months); then explore what changes might occur during a hypothesized phase transition (15 to 18 months), and finally, review the emergence and initial stabilization of individual subjectivity-the period from 18 to 36 months. The critical questions explored focus on how to model and translate data from very different experimental disciplines, especially neuroscience, physiology, developmental psychology and cognitive development. I close by proposing the formation of a research consortium on gender/sex development during the first 3 years after birth.

The Effects of Race, Gender, and Gender-Typed Behavior on Children's Friendship Appraisals

From a young age, children's peer appraisals are influenced by the social categories to which peers belong based on factors such as race and gender. To date, research regarding the manner in which race- and gender-related factors might interact to influence these appraisals has been limited. The present study employed an experimental vignette paradigm to investigate the relative influences of target peers' race, gender, and gender-typed behavior toward 4- to 6-year-old Chinese children's (N = 119, 62 girls, 57 boys) peer appraisals. Appraisals were assessed via (1) a rating scale measuring children's interest in being friends with a range of hypothetical target peers varying in race, gender, and gender-typed behavior, and (2) a forced-choice rank-order task in which children indicated their preferences for four hypothetical target peers who varied from themselves on either race, gender, or gender-typed behavior, or were similar to themselves on all three traits. There was little evidence to suggest children's rank-ordered peer preferences in relation to race were influenced by whether the other-race presented was White (preferred relatively more) or Black (preferred relatively less). In contrast, gender-related factors (i.e., rater gender, target gender, target gender-typed behavior) had more robust influences on peer preferences for both outcome measures. Gender-conforming peers were preferred over gender-nonconforming peers, and target boys displaying feminine behavior were less preferred than target girls displaying masculine behavior. The results help characterize cross-cultural (in)consistencies in children's social preferences in relation to peers' race and gender.

Prenatal androgen exposure and children's gender-typed behavior and toy and playmate preferences

We report findings from two studies investigating possible relations of prenatal androgen exposure to a broad measure of children's gender-typed behavior, as well as specifically to children's toy and playmate preferences. Study 1 investigated these outcomes for 43 girls and 38 boys, aged 4 to 11 years, with congenital adrenal hyperplasia (CAH, a genetic condition causing increased adrenal androgen production beginning prenatally) compared to similarly-aged, unaffected relatives (41 girls, 31 boys). The predicted sex differences were found for all of the outcome measures. Furthermore, girls with CAH showed increased male-typical and decreased female-typical behavior and toy and playmate preferences compared to unaffected girls. Study 2 investigated the relationship of amniotic fluid testosterone to gender-typed behavior and toy and playmate preferences in typically developing children (48 girls, 44 boys) aged 3 to 5 years. Although the predicted sex differences were found for all of the outcome measures, amniotic fluid testosterone was not a significant correlate, in the predicted direction, of any outcome measure for either sex. The results of study 1 provide additional support for an influence of prenatal androgen exposure on children's gender-typed behavior, including toy and playmate preferences. The results of study 2 do not, but amniotic fluid testosterone may be an insufficiently sensitive measure of early androgen exposure. A more sensitive and reliable measure of prenatal androgen exposure may be needed to consistently detect relations to later gender typed behavior in non-clinical populations.

A Systematic Review Comparing the Play Profiles of Children with Special Health Care Needs with Typically Developing Children

INTRODUCTION

Although play has been used as a means to meet therapeutic goals by health care practitioners for a long time, there is a need to continuously review its conceptualisation and use in everyday practice to promote evidence-based practice. This systematic review aimed to evaluate the evidence on how the play of children with Special Health Care Needs (SHCN) is similar or different to that of typically developing children.

METHODS

Guided by the preferred reporting items for systematic reviews and meta-analyses (PRISMA) statement, we conducted a comprehensive review across five electronic databases for all studies that compared how the play of children with SHCN was similar or different to that of typically developing children. Data were extracted from the included studies, and methodological quality was assessed.

RESULTS

Eighteen studies met eligibility criteria. All the studies in this review were at risk of bias due to the study design. There was great variation in sample sizes, ranging between five and 112 participants in the diagnostic groups and five and 546 participants in control groups (typically developing children). The included studies investigated different aspects of play, which made it difficult to synthesise. However, of the 18 studies reviewed, thirteen reported that children with SHCN engage in less play, compared with typically developing children.

CONCLUSIONS

Evidence supports the assumption that children with SHCN are less playful and spend less time engaging in play compared with typically developing children. This systematic review reveals paucity of research on play for children with several common chronic conditions such as HIV/AIDS, cancer, and cardiovascular diseases. Future studies need to reduce risks of bias, including the use of appropriate sample sizes, and must provide detailed results after investigating play in children with SHCN.

The Epistemology of Evolutionary Psychology Offers a Rapprochement to Cultural Psychology

Many detractors of evolutionary psychology (EP) presume that adaptive arguments are nothing more than whimsical and unfalsifiable just-so stories. The reality though is that the epistemology of EP is precisely the opposite of this antiquated canard in that it fixes the evidentiary threshold much higher than is typically achieved by most scientists. EP amasses evidence across cultures, time periods, disciplines, paradigms, methodologies, and units of analyses in validating a given scientific explanation. These nomological networks of cumulative evidence stimulate greater interdisciplinarity, lesser methodological myopia, and increased consilience (unity of knowledge). A component in building such nomological networks is to examine phenomena that are cross-culturally invariant (human universals) versus those that vary cross-culturally as adaptive responses (the domain of behavioral ecologists and gene-culture coevolution modelers). The epistemological efficacy of this unique approach is highlighted using two cases studies, the sex-specificity of toy preferences and men’s preference for the hourglass figure.

Parent-Reports of Sex-Typed Play Preference in Preschool Children: Relationships to 2D:4D Digit Ratio and Older Siblings' Sex

Sex-typed play behavior shows large sex differences and seems to be affected by prenatal sex hormones. For example, a smaller, more male-typical ratio between the second and fourth digit length (2D:4D), a proposed marker for prenatal testosterone exposure, has been shown to be related to sex-typed play preference in childhood. Nevertheless, it is still being debated whether 2D:4D displays a stable sex difference throughout childhood, as there are few longitudinal studies. In the present study, children's 2D:4D was measured on both hands on four occasions from early infancy to early childhood (T1: 5 months, T2: 9 months, T3: 20 months, and T4: 40 months) providing the rare possibility to test the temporal stability of the sex difference. Parents completed the Preschool Activities Inventory at T4 and reported on the number of older brothers and sisters as a measure for socialization influences. Parents described boys as playing more masculine and less feminine than girls. Boys had smaller 2D:4D than girls at all measurements (T1-T4) and on both hands (right/left). Nevertheless, 2D:4D increased significantly from T3 to T4 in both sexes. Girls, but not boys, who were described as playing more masculine and less feminine had more masculine 2D:4D ratios at T1-T4 on both hands (except for right 2D:4D at T2 and T3) and had more older brothers and fewer older sisters. These data underline the stability of the sex difference in 2D:4D and show the importance of both biological and social influences on sex-typed play behavior.

Evolution of the Habits of Physical Activity and Television Viewing in Spanish Children and Pre-Adolescents between 1997 and 2017

Background: Promoting healthy lifestyles in children, has become a priority for public health institutions. However, electronic devices with screens encourage sedentary behaviors. The aim of this study was to analyze the evolution of the habits of physical activity practice and television watching in a cohort of 20 years of research in Spanish children. Methods: A cross-sectional, observational study was based on data from the Spain National Health Surveys between 1997 and 2017 (N = 11,444). The dependent variables considered were the frequency with which the minor practiced physical activity (PA) in his/her spare time, the daily TV viewing habit, and the daily hours of TV viewing. Results: The children who practiced physical activity daily has decreased 7.3% throughout the study period. The proportion of children who watched the television daily for more hours increased significantly (6.3%). Such increase was constant throughout the years, and the analysis by sex showed that the proportion of boys who watched television for more than three hours per day increased three percent, and that of girls increased fourfold. Conclusions: The habits of physical activity practice and television viewing have changed towards sedentary lifestyle. Particularly, the girls and the children between 12 and 14 years showed the most sedentary behavior. Public health policies must consider the differences between sexes in order for such interventions to be effective in the population of pre-adolescents, in general, and girls, in particular.

Factors affecting infant toy preferences: Age, gender, experience, motor development, and parental attitude

In contrast to the anecdotal claim that "male infants like cars and female infants like dolls," previous studies have reported mixed findings for gender-related toy preferences in infancy. In Experiment 1, we explored the emergence of gender-related preferences using face-car pairs (Experiment 1a, n = 51, 6-20 months) or face-stove pairs (Experiment 1b, n = 54, 6-20 months). In Experiment 2 (n = 42, 14-16 months), we explore the effect of toy properties, infants' past toy exposure, activity levels, and parental attitudes on such preferences using a wider range of toys. For both studies, infants demonstrated a general preference for faced stimuli over other objects, except for male infants who showed no preference between dolls and cars at around 15 months. Infants' prior experience participating in motor-intensive activities, with wheeled toys and parental attitudes appeared to relate to female infants' preferences for dynamic toys. These results indicate a range of factors influence gendered toy preferences and suggest that nurture plays an important role.

Individual differences in visualization and childhood play preferences

Our research explored the structure of childhood visual play preferences, and examined different types of visual play in relation to individual differences in visualization and aptitudes in academic specializations requiring visualization skills. Principal component analysis dissociated visual-object play (e.g., exploring drawing media or decorative crafts) from visual-spatial play (e.g., assembling and disassembling mechanisms or playing with construction toys) preferences. Moreover, visual play preferences were dissociated from verbal play preferences (e.g., vocabulary games or making up stories). The structure of visual play preferences was consistent with object and spatial dimensions of individual differences in visualization. Visual-object and visual-spatial dimensions of play preferences were differentially related to measures of object visualization (processing pictorial appearances in terms of shape, texture, and color) versus spatial visualization (processing spatial relationships and spatial manipulations), as well as to aptitudes in artistic versus scientific domains. Furthermore, our research sheds new light on sex differences in play behavior: Previous studies commonly associated gender-specific play with visual versus verbal-social processing; our research demonstrated sex differences in play preferences across the two dimensions of visual play, where females preferred visual-object and males preferred visual-spatial play. Moreover, we found the object vs. spatial structure of visual play preferences was largely the same in both sexes, suggesting that differences in visual play preferences cannot be reduced to sex differences. Also, our questionnaire assessing visual-object, visual-spatial and verbal play preferences, developed for research purposes, demonstrated good reliability. Its two scales, assessing visual-object and visual-spatial play preferences, discriminatively correlated with assessments of individual differences in object and spatial visualization, respectively. This research creates a basis for further creation of comprehensive measures of visual play preferences, and should stimulate future studies examining visual play preferences and how they may create developmental opportunities for skills and preferences lasting into adulthood.

How Large Are Gender Differences in Toy Preferences? A Systematic Review and Meta-Analysis of Toy Preference Research

It is generally recognized that there are gender-related differences in children's toy preferences. However, the magnitude of these differences has not been firmly established. Furthermore, not all studies of gender-related toy preferences find significant gender differences. These inconsistent findings could result from using different toys or methods to measure toy preferences or from studying children of different ages. Our systematic review and meta-analysis combined 113 effect sizes from 75 studies to estimate the magnitude of gender-related differences in toy preferences. We also assessed the impact of using different toys or methods to assess these differences, as well as the effect of age on gender-related toy preferences. Boys preferred boy-related toys more than girls did, and girls preferred girl-related toys more than boys did. These differences were large (d ≥ 1.60). Girls also preferred toys that researchers classified as neutral more than boys did (d = 0.29). Preferences for gender-typical over gender-atypical toys were also large and significant (d ≥ 1.20), and girls and boys showed gender-related differences of similar magnitude. When only dolls and vehicles were considered, within-sex differences were even larger and of comparable size for boys and girls. Researchers sometimes misclassified toys, perhaps contributing to an apparent gender difference in preference for neutral toys. Forced choice methods produced larger gender-related differences than other methods, and gender-related differences increased with age.

How Large Are Gender Differences in Toy Preferences? A Systematic Review and Meta-Analysis of Toy Preference Research

It is generally recognized that there are gender-related differences in children's toy preferences. However, the magnitude of these differences has not been firmly established. Furthermore, not all studies of gender-related toy preferences find significant gender differences. These inconsistent findings could result from using different toys or methods to measure toy preferences or from studying children of different ages. Our systematic review and meta-analysis combined 113 effect sizes from 75 studies to estimate the magnitude of gender-related differences in toy preferences. We also assessed the impact of using different toys or methods to assess these differences, as well as the effect of age on gender-related toy preferences. Boys preferred boy-related toys more than girls did, and girls preferred girl-related toys more than boys did. These differences were large (d ≥ 1.60). Girls also preferred toys that researchers classified as neutral more than boys did (d = 0.29). Preferences for gender-typical over gender-atypical toys were also large and significant (d ≥ 1.20), and girls and boys showed gender-related differences of similar magnitude. When only dolls and vehicles were considered, within-sex differences were even larger and of comparable size for boys and girls. Researchers sometimes misclassified toys, perhaps contributing to an apparent gender difference in preference for neutral toys. Forced choice methods produced larger gender-related differences than other methods, and gender-related differences increased with age.

Social and Object Attention Is Influenced by Biological Sex and Toy Gender-Congruence in Children With and Without Autism

Emerging research suggests social attention in autism spectrum disorder (ASD) girls is enhanced relative to ASD boys but may also be affected by the type of social and nonsocial content presented. This study examined how biological sex and gender norms interact to influence visual attention in 79 school-aged children observing scenes that included gender-associated toys and actors of both sexes. Attention to social (faces) and object activity (hands with toys) stimuli was measured. Previously described distinctions between social attention in ASD boys and girls were replicated, with ASD girls looking more at faces than ASD boys. Irrespective of diagnosis, males and females attended more to actors that shared their same sex, and attended more to toys with gender-associations that were consistent with their own sex, suggesting that social and object salience increases for children under sex-consistent conditions. Importantly, ASD and typically developing (TD) children increased their gaze to faces when male actors were shown playing with female-associated toys, suggesting that both groups of children are sensitive to societal messages about the acceptability of males playing with female-associated toys. Our findings provide further evidence of heightened attention to faces in ASD girls relative to ASD boys, and indicate that social attention in ASD and TD children is influenced by who (male or female actor) and what (male- or female-associated toy) is being observed. Collectively, these results present a nuanced profile of attention in ASD that adds to a growing body of research indicating subtle phenotypic differences in ASD girls that may impact identification, assessment, and intervention. Autism Res 2020, 13: 763-776.. © 2019 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: Sex differences observed in typical development may also be present in individuals with autism. In this study, we developed an eye-tracking paradigm featuring videos of boys and girls playing with toys that varied in their gender associations. Attention to faces differed between autistic and non-autistic children but was also influenced by the sex of the actor and gender-association of toys. Autistic females demonstrated subtle attention differences that distinguished them from autistic males and may influence referral, diagnosis, and intervention.

Parents' Autistic Personality Traits and Sex-Biased Family Ratio Determine the Amount of Technical Toy Choice

We investigated the effect of parents' autism quotient (AQ), their sex and the sex of their children on their toy preference. In a computerized forced-choice shopping task, adults selected from cuddly and social role-playing toys (social toys), academic, music and sports toys (educational toys) and construction sets as well as cars (technical toys). A sex-balanced high and low AQ sample of 160 adults consisted of groups of parents of sons only, daughters only, sons and daughters, as well as of a group of adults without children (non-parents). The standard toy preference was social toys < educational toys < technical toys. Low AQ women were the only group to make a significantly higher amount of educational and a lower amount of technical toy choices. The mere presence of just sons increased technical toy choice in this experiment, while the mere presence of just daughters reduced technical toy choice both in men and high AQ individuals.

Early Gender Differences in Spatial and Social Skills and Their Relations to Play and Parental Socialization in Children from Hong Kong

Children's play preferences are highly gender-typed. At the same time, much research revolves around spatial and social skills that sometimes show male and female advantages, respectively. There is evidence that play with masculine toys is associated with better spatial skills and emerging evidence suggests that play with feminine toys is associated with better social skills. However, several research gaps limit current knowledge on these aspects of gender development. First, the study of childhood gender development has been largely Eurocentric; second, the link between gender-typed play and social skills development is not well supported. We tested 644 5-year-old Hong Kong Chinese children on five gender-typed skills, play preferences, and parental gender socialization. The pattern of gender differences was remarkably similar to those in the West. Boys preferred masculine toys more than girls and were better at mental transformation and targeting accuracy, while girls preferred feminine (and neutral) toys more than boys and were better at empathy and were less aggressive, although there was no significant gender difference in comforting skill. There was little evidence that these gender differences varied with socioeconomic status (parental income and education). Play correlated with some outcomes in expected ways. This is in contrast to parents' gender socialization, which showed some expected differences by child gender but minimally correlated with children's skills. These findings shed light on the generalizability of current knowledge on early gender differences and may facilitate gender developmental research outside the West. Although the study did not test the direction of effects, they substantiate the growing discourse on gender-typed play as an important learning mechanism.

Childhood Sex-Typed Behavior and Gender Change in Individuals with 46,XY and 46,XX Disorders of Sex Development: An Iranian Multicenter Study

Disorders of sex development (DSD) are congenital conditions in which the typical genetic and hormonal profiles are affected and thereby the usual process of sexual differentiation. Most of these studies, however, have been conducted in Western countries. In the present study, preschool sex-typed activities of Iranian individuals with DSD and their age-matched non-affected male and female relatives were assessed using the Pre-School Activities Inventory (PSAI) modified for retrospective self-report. A total of 192 individuals participated in our study, including 33 46,XX individuals with congenital adrenal hyperplasia (CAH; M age = 10.36, SD = 5.52), 15 46,XY individuals with complete androgen insensitivity syndrome (CAIS; M age = 19.8, SD = 7.14), and 16 46,XY individuals with 5-alpha reductase deficiency type-2 (5α-RD-2; M age = 17.31, SD = 7.28), as well as one age-matched non-affected male and female relative for each patient. With regard to PSAI scores, male-identifying participants with 5α-RD-2 and male controls reported similar levels of male-typical childhood play. Female-identifying participants with 5α-RD-2 and CAH showed comparable scores: significantly less masculine and more feminine than male controls, but significantly more masculine and less feminine than females with CAIS and female controls. These findings support the role of androgens in the development of sex-typical childhood play behavior, with those being exposed to higher levels of fetal functional androgens expressing more masculine behavior at preschool ages.

The left cradling bias: An evolutionary facilitator of social cognition?

A robust left side cradling bias (LCB) in humans is argued to reflect an evolutionarily old left visual field bias and right hemisphere dominance for processing social stimuli. A left visual field bias for face processing, invoked via the LCB, is known to reflect a human population-level right cerebral hemisphere specialization for processing social stimuli. We explored the relationship between cradling side biases, hand dominance and socio-communicative abilities. Four and five year old typically-developing children (N = 98) participated in a battery of manual motor tasks interspersed by cradling trials comprising a(n): infant human doll, infant primate doll, proto-face pillow and no-face pillow. Mean social and communication ability scores were obtained via a survey completed by each child's key teacher. We found a population-level LCB for holding an infant human doll that was not influenced by hand dominance, sex, age or experience of having a younger sibling. Children demonstrating a LCB, did however, obtain a significantly higher mean social ability score compared with their right side cradling counterparts. Like the infant human doll, the proto-face pillow's schematic face symbol was sufficient to elicit a population-level LCB. By contrast, the infant primate doll elicited a population-level right side cradling bias, influenced by both hand dominance and sex. The findings suggest that the LCB is present and visible early in development and is likely therefore, to represent evolutionarily old domain-specific organization and function of the right cerebral hemisphere. Additionally, results suggest that a LCB requires minimal triggering but can be reversed in some situations, possibly in response to species-type or levels of novelty or stress as perceived by the viewer. Patterns of behavioral biases within the context of social stimuli and their associations with cognitive ability are important for understanding how socio-communication abilities emerge in developing children.