Femininity and fertility in sisters with twin brothers: prenatal androgenization? Cross-sex socialization?

Are sisters of twin brothers behaviorally or physiologically masculinized? Prenatal exposure to their brothers' androgens and postnatal socialization experiences unique to girls growing up with twin brothers might influence their attitudes, pubertal development, and reproductive histories. To investigate, we studied age- and cohort-matched samples of Finnish sisters from same-sex and opposite-sex twin pairs. Using data from two ongoing longitudinal studies of consecutive birth cohorts of Finnish twins, we assessed pubertal development at ages 11 and 14 and endorsement of attitudes associated with femininity at age 16. We also studied fertility in Finnish women from same- and opposite-sex twin pairs born from 1958 through 1971, obtaining information on their child-bearing histories when they were ages 15 to 28. Results of each comparison were unambiguously negative: There was no evidence of differences between sisters from same- and opposite-sex twin pairs, and thus, no evidence of either androgenization or cross-sex socialization.     

Effortful Control in “Hot” and “Cool” Tasks Differentially Predicts Children’s Behavior Problems and Academic Performance

Effortful control (EC), the capacity to deliberately suppress a dominant response and perform a subdominant response, rapidly developing in toddler and preschool age, has been shown to be a robust predictor of children’s adjustment. Not settled, however, is whether a view of EC as a heterogeneous rather than unidimensional construct may offer advantages in the context of predicting diverse developmental outcomes. This study focused on the potential distinction between “hot” EC function (delay-of-gratification tasks that called for suppressing an emotionally charged response) and more abstract “cool” EC functions (motor inhibition tasks, suppressing-initiating response or Go-No Go tasks, and effortful attention or Stroop-like tasks). Children (N?=?100) were observed performing EC tasks at 38 and 52 months. Mothers, fathers, and teachers rated children’s behavior problems and academic performance at 67, 80, and 100 months, and children participated in a clinical interview at 100 months. Structural Equation Modeling (SEM) analyses with latent variables produced consistent findings across all informants: Children’s scores in “hot” EC tasks, presumably engaging emotion regulation skills, predicted behavior problems but not academic performance, whereas their scores in “cool” EC tasks, specifically those engaging effortful attention, predicted academic performance but not behavior problems. The models of EC as a heterogeneous construct offered some advantages over the unidimensional models. Methodological and clinical implications of the findings are discussed.     

Controlling reactive aggression through cognitive evaluation of proactive aggression cues

The authors investigated how the relationship between the acts of proactive and reactive aggression was moderated by the individual differences in cognitive regulation of emotion. An aggression paradigm, a electrocardiogram recording, a cognitive assessment battery, and a short form IQ test were completed by 109 children, aged 8 to 13 years (Juujärvi, Kaartinen, Laitinen, Vanninen, & Pulkkinen, 2006 Juujärvi, P., Kaartinen, J., Laitinen, T., Vanninen, E. and Pulkkinen, L. 2006. Effects of physical provocations on heart rate reactivity, and reactive aggression in children. Aggressive Behavior, 32: 99–109. [Crossref], [Web of Science ®] , [Google Scholar]; Juujärvi, Kooistra, Kaartinen, & Pulkkinen, 2001 Juujärvi, P., Kooistra, L., Kaartinen, J. and Pulkkinen, L. 2001. An aggression machine: V. Determinants of reactive aggression revisited. Aggressive Behavior, 27: 430–445. [Crossref], [Web of Science ®] , [Google Scholar]; Lehto, Juujärvi, Kooistra, & Pulkkinen, 2003 Lehto, J. E., Juujärvi, P., Kooistra, L. and Pulkkinen, L. 2003. Dimensions of executive functioning: Evidence from children. British Journal of Developmental Psychology, 21: 59–80. [Crossref], [Web of Science ®] , [Google Scholar]). The less the children subdued the intensity of their defence to the attacks in the aggression paradigm, the poorer they performed in the cognitive assessment battery tasks measuring Working memory capacity and in the task assessing crystallised intelligence. The mean cardiovascular reactivity during the aggression paradigm was neither associated with the performances in either the cognitive assessment battery nor the intelligence tasks. Both information processing and knowledge dimensions of cognition contributed to regulation of emotion, but the respective effects of the processes cannot be inferred from the mean cardiovascular reactivity.     

Young Children's Knowledge of the Representational Function of Pictorial Symbols: Development Across the Preschool Years in Three Cultures

Three- to 5-year-old children's knowledge that pictures have a representational function for others was investigated using a pictorial false-belief task. In Study 1, children passed the task at around 4 years old, and performance was correlated with standard false-belief and pictorial symbol tasks. In Study 2, the performance of children from two cultural settings who had very little exposure to pictures during the first 3 years (Peru, India) was contrasted with that of children from Canada. Performance was better in the Canadian than Peruvian and Indian samples on the picture false-belief task and drawing tasks but not on the standard false-belief measure. In all settings, children passed drawing and standard false-belief tasks either concurrently with, or prior to, passing the picture false-belief task. The findings suggest that children's explicit knowledge of the representational function of pictorial symbols matures in the late preschool years and develops more rapidly in cultures that strongly promote the symbolic use of pictures early in life.     

Confidence Intervals for the Probability of Superiority Effect Size Measure and the Area Under a Receiver Operating Characteristic Curve

It is good scientific practice to the report an appropriate estimate of effect size and a confidence interval (CI) to indicate the precision with which a population effect was estimated. For comparisons of 2 independent groups, a probability-based effect size estimator (A) that is equal to the area under a receiver operating characteristic curve and closely related to the popular Wilcoxon-Mann-Whitney nonparametric statistical tests has many appealing properties (e.g., easy to understand, robust to violations of parametric assumptions, insensitive to outliers). We performed a simulation study to compare 9 analytic and 3 empirical (bootstrap) methods for constructing a CI for A that can yield very different CIs for the same data. The experimental design crossed 6 factors to yield a total of 324 cells representing challenging but realistic data conditions. Results were examined using several criteria, with emphasis placed on the extent to which observed CI coverage probabilities approximated nominal levels. Based on the simulation study results, the bias-corrected and accelerated bootstrap method is recommended for constructing a CI for the A statistic; bootstrap methods also provided the least biased and most accurate standard error of A. An empirical illustration examining score differences on a citation-based index of scholarly impact across faculty at low-ranked versus high-ranked research universities underscores the importance of choosing an appropriate CI method.     

Adults' Efficacy and Control Beliefs Regarding Memory and Aging: Separating General from Personal Beliefs

This study examined beliefs about memory in 307 18-93 year-old community-dwelling adults. Two new questionnaires, the General Beliefs about Memory (GBMI) and the Personal Beliefs about Memory (PBMI) Instruments, were used to compare and contrast beliefs about memory in the general population of adults from beliefs about one's own memory. Both questionnaires used a graphic rating scale format to obtain more refined responses. The GBMI showed that, on average, all age groups perceived the average adult as experiencing curvilinear decline over the adult life span for multiple aspects of memory, with the greatest changes believed to occur after age 40. Beliefs about different specific types of memory were consistent with lay beliefs and with empirical results regarding aging and memory (e.g., memory for names was perceived to decline more rapidly than memory for faces). In contrast to earlier studies, small but significant age differences between young, middle-aged, and older respondents regarding beliefs about rates of memory aging were identified. Results for the PBMI indicated that personal beliefs were strongly related to, but distinct from, general beliefs. Older adults believed themselves to be lower in memory efficacy, to have declined more than younger adults, and to have less personal control over memory, as in earlier research.     

Associations between authoritative parenting and the sun exposure and sun protective behaviours of adolescents and their friends

Associations between the sun exposure and sun protective behaviours of adolescents and their friends were examined along with the role played by authoritative parenting and other family and peer socialisation factors. Four hundred and two adolescents (198 males, 204 females) participated in the research. It was found that these adolescents and their friends shared similar sun exposure and sun protective behaviours and had similar parenting backgrounds. Parental authoritativeness was positively associated with the use of sun protection, even after the effects of other familial and peer variables were controlled, but not with the time spent sunbathing which was associated with friends’ behaviours. The theoretical and practical implications of these findings are discussed.     

Abstracting Sequences: Reasoning That Is a Key to Academic Achievement

The ability to understand sequences of items may be an important cognitive ability. To test this proposition, 8 first-grade children from each of 36 classes were randomly assigned to four conditions. Some were taught sequences that represented increasing or decreasing values, or were symmetrical, or were rotations of an object through 6 or 8 positions. Control children received equal numbers of sessions on mathematics, reading, or social studies. Instruction was conducted three times weekly in 15-min sessions for seven months. In May, the children taught sequences applied their understanding to novel sequences, and scored as well or better on three standardized reading tests as the control children. They outscored all children on tests of mathematics concepts, and scored better than control children on some mathematics scales. These findings indicate that developing an understanding of sequences is a form of abstraction, probably involving fluid reasoning, that provides a foundation for academic achievement in early education.