Psychology, Developmental

In Study 1, fourth--through seventh-grade children (mean age = 11.5 years) were asked to estimate the likelihood that various outcomes would occur following hypothetical acts of aggression by themselves toward victimized and nonvictimized peers. Subjects were also asked to indicate how much they valued the occurrence of the outcomes. When the targets of the aggression were victimized peers, children were more likely to anticipate tangible rewards, more likely to expect signs of victim suffering, and less likely to anticipate retaliation than when aggressing against nonvictimized peers. Also, children placed greater value on securing tangible rewards but were less concerned by the thought of hurting or by the thought of their target retaliating when attacking a victimized peer than attacking a nonvictimized peer. This pattern was stronger for boys than for girls. Study 2 was designed to see what evaluative reactions fourth--through seventh-grade children (mean age = 11.3 years) would expect from themselves, from peers, and from teachers for aggression against victimized and nonvictimized peers. When contemplating aggressing against a victimized peer, children expected less disapproval from self and peers. A second purpose of Study 2 was to determine whether children were more likely to display hostile attributional bias toward victimized peers than toward nonvictimized peers. As predicted, hostile attributional bias was greater toward victimized peers than toward nonvictimized peers. Implications for theories of aggression, future areas of research, and for intervention with victimized children are discussed.

This research explored group differences according to giftedness and achievement in the acquisition and generalization of a strategy for solving analogies. A distinction was made between proximal and distal transfer, with the latter expected to differentiate between gifted and nongifted cognition. Underachievement in gifted children was expected to reflect either strategy deficits, or the absence of performance differences in a theoretically important cognitive skill (generalization) between the so-called "underachieving" gifted and other bright but nongifted children. 162 seventh and eighth graders were selected according to intelligence and achievement scores, academic program, and teacher opinion, and assigned to one of four groups: high achieving gifted, underachieving gifted, high achieving nongifted, and average achieving nongifted. Each child was seen individually for two sessions, and solved a total of five sets of ten multiple-choice analogies. The first session included two baseline trials (one verbal and one figural set), followed by training in the use of a strategy. The second session included a proximal transfer trial (same analogy type as used at training), and a distal transfer trial (analogies from the never-trained domain). All analogies were solved orally, and strategy use was determined from audio-recordings. The results showed that the high achieving gifted children were more spontaneously, frequently, and successfully strategic than the other three groups, as well as most accurate following the decision not to use a strategy. They were also the only group to show performance increases at distal transfer. In terms of gifted underachievement, there was evidence to support both hypotheses. The underachieving gifted children showed qualitative deficits in strategic functioning as compared to their high achieving gifted counterparts, and also tended to "look" like the high achieving nongifted group in their patterns of performance. These results were discussed in terms of the likelihood of subgroups of underachieving gifted children, and their implications for education and the identification of giftedness.

This study examined the hypothesis that both exposure to reading materials in the home and intrinsic motivation to read mediate the relationship between socioeconomic status and reading comprehension skills in adolescents. Data were derived from the Program for International Student Assessment 2000 dataset (PISA 2000). Six countries out of forty-three were chosen on the basis of country-level SES: two from the bottom 25th percentile (Thailand, Mexico), two at the 50th percentile (Austria, France), and two at the 75th percentile (Norway, United States). Data analysis was conducted on a total of 27,351 participants and 823 schools. Hierarchical linear modeling (HLM) analyses were conducted to examine predictors of reading comprehension skills. Follow-up analyses using logistic regression were conducted to predict group membership (i.e., poor vs. normal readers). Results support the idea that exposure to reading materials in the home mediates the relationship between SES and reading comprehension skills at the child level, regardless of the overall economic state of the country. This relationship did not hold when predicting at the school level. Intrinsic motivation to read was consistently a poor predictor.

Research in the psychological sciences has long focused on the impact families have on later development. One feature of families is the birth order in which children from one family develop. Birth order serves as a proxy for developmentally relevant criteria including differences in age, size, and status between siblings. Following from theories derived from evolutionary psychology, differences in perceived favoritism, personality dimensions, and sexual strategy are examined. As an initial examination of the influences siblings can have beyond childhood, responses to the upset over the infidelities of in-laws are examined. Results from this series of studies suggests (1) birth order does not covary with personality but that distinctions among the relatedness between siblings can provide fruitful avenues of future research, (2) features of sexual strategy do covary with birth order, particularly variables related to projected sexual strategy, (3) perceptions of parental favoritism covary with the birth order of the participant, and (4) men and women do not differ in their upset over the infidelities of brothers-in-law and sisters-in-law but that the mechanisms generating upset over a sibling-in-law's infidelity may be sensitive to the age of the sibling and thus, the birth orders of the participant and sibling.

Cross-cultural empirical data show that stepchildren receive lower levels of parental investment than their genetic counterparts. Beyond economic deprivation, stepchildren are abused, neglected, and murdered at the hands of stepparents at significantly higher rates than their genetic counterparts (the Cinderella Effect). This study was focused on emotional capital as a resource for purposes of parental investment. Using the tools of dynamical systems, this study investigated the affective components of the differential levels of parental investment in genetic and step-children in light of predictions derived from evolutionary and personality/synchronization based psychological mechanisms. This was accomplished by defining and comparing the valence and nature of step- and genetic parents' feelings toward genetic and step-children and by tracking the mental dynamics engaged in by such parents as they considered their genetic and step-children under varying commonplace circumstances. As predicted, positive affective parental investment was found to be allocated preferentially in favor of genetic children and parents were found to have consistently more positive, more parental, and less volatile feelings about their genetic children than about their stepchildren. Genetic parents were more attentive to environmental cues at an affective level and tended to resolve situational ambiguity in favor of adopting a positive affective stance, while stepparents were more prone to experience affective shifts between evaluative frames and to express negative affectivity in the face of social uncertainty. The data also revealed that both genetic and step-parents were more likely to express positive feelings for children to whom they felt similar, which similarity provided a basis for personal synchronization. Theoretically grounded in both the evolutionary perspective and personality-based theory, this study employed the methodology and tools of dynamical systems to extract structure from the dynamics inherent in parental evaluation and the expression of affect.

The purpose of this study was twofold: first, this research was conducted in order to replicate and extend Egan and Perry's (2001) work linking four components of gender identity to adjustment; second, this research was intended to extend knowledge of the relation between gender identity and affiliational patterns in the peer group. Measures of gender identity were (a) feelings of gender typicality, (b) contentment with one's gender assignment, (c) felt pressure for gender conformity, and (d) intergroup bias (feeling that one's own sex is superior to the other). Measures of adjustment included self-esteem, peer rejection, victimization by peers, and specific social behaviors. Participants were 206 children in Grades 3 through 8. Low gender typicality, low gender contentedness, and high felt pressure were all associated with maladjustment. Furthermore, children were especially likely to be at risk for poor adjustment when two of these factors occurred together (e.g., low gender typicality in combination with high felt pressure, low gender contentedness in combination with high felt pressure, or low gender typicality in combination with low gender contentedness). Intergroup bias was unrelated to adjustment. Analyses relating gender identity to characteristics of reciprocated friends and disliked peers indicated that children tend to choose friends with similar clusters of gender identity-linked characteristics and avoid children who do not possess those characteristics. Interpretations and directions for future research are offered.

Autism, characterized by disrupted social interaction and communication skills, and Attention Deficit Hyperactivity Disorder (ADHD), characterized by hyperactivity and inattention, are two neurodevelopmental disorders that have recently been linked to common dysfunctions in the frontal lobes and cerebellum. The present study was designed to evaluate the neonatal rat as an animal model for neurodevelopmental disorders. The behavior of rats with early Frontal (FR), Cerebellar (CB), or Frontal + Cerebellar (FR + CB) lesions, performed at either Post-natal Day 2 (PD 2) or 9 (PD 9), was evaluated with regard to activity, learning, social, and emotional behavior between the age of 3--31 days. In Experiment 1, 3 and 10-day-old pups were tested on their ability to habituate to a novel odor. FR lesions increased activity in 3-days-olds while CB, and FR + CB lesions disrupted odor habituation learning in 10-day-olds. In Experiment 2, 17-day-old pups were evaluated on activity in the open-field and ability to habituate to a novel environment. FR lesions resulted in increased locomotor activity while CB lesions resulted in increased grooming, a stereotypical behavior. Pups with PD 9 CB lesions also failed to habituate to the novel environment of the open-field. In Experiment 3, 24-day-old juveniles were evaluated on social behavior in the play test, as measured by frequency of pinning behavior. FR lesions increased levels of play behavior while CB lesions decreased play. In Experiment 4, 31-day-old juveniles were evaluated on emotionality in the elevated plus maze as measured by the number of distal open arms entries. Rats with CB lesions made twice as many distal open arm entries relative to the other lesioned groups; however, this result did not reach statistical significance. In conclusion, the results of the present study suggest that the effects of early frontal and cerebellar lesions can be dissociated on several different behavioral measures in young rats. Furthermore, neonatal rats with frontal and cerebellar lesions exhibit several behaviors during ontogeny that mimic those seen in children with ADHD and autism, such as hyperactivity and disrupted social interaction. The neonatal rat may thus prove to be a useful animal model for childhood neurodevelopmental disorders.