Primate social cognition and the origins of language

Are the cognitive mechanisms underlying language unique, or can similar mechanisms be found in other domains? Recent field experiments demonstrate that baboons' knowledge of their companions' social relationships is based on discrete-valued traits (identity, rank, kinship) that are combined to create a representation of social relations that is hierarchically structured, open-ended, rule-governed, and independent of sensory modality. The mechanisms underlying language might have evolved from the social knowledge of our pre-linguistic primate ancestors.     

Developmental dyslexia and specific language impairment: same or different?

Developmental dyslexia and specific language impairment (SLI) were for many years treated as distinct disorders but are now often regarded as different manifestations of the same underlying problem, differing only in severity or developmental stage. The merging of these categories has been motivated by the reconceptualization of dyslexia as a language disorder in which phonological processing is deficient. The authors argue that this focus underestimates the independent influence of semantic and syntactic deficits, which are widespread in SLI and which affect reading comprehension and impair attainment of fluent reading in adolescence. The authors suggest that 2 dimensions of impairment are needed to conceptualize the relationship between these disorders and to capture phenotypic features that are important for identifying neurobiologically and etiologically coherent subgroups.     

Bullying and victimization: prevalence and relationship to gender, grade level, ethnicity, self-esteem, and depression

This study investigated the prevalence of bullying and victimization among students in grades 7 and 8. It also explored the relationship of bullying and victimization to gender, grade level, ethnicity, self-esteem, and depression. Three survey instruments were used to obtain data from a convenience sample of 454 public school students. Twenty-four percent reported bullying involvement. Chi-square tests indicated significantly more male than female bullying involvement, seventh graders reported more involvement than did eighth graders, and there were no statistically significant differences in involvement based on ethnicity. Both bullies and victims manifested higher levels of depression than did students who were neither bullies nor victims. There were no significant differences between groups in terms of self-esteem.     

Examining the construct validity of the Eating Disorder Inventory

The construct validity of the Eating Disorder Inventory (EDI) was examined in 3 samples. An archival clinic sample (n = 318) of women completed the EDI, a structured interview, and the Millon Clinical Multiaxial Inventory-II (MCMI-II). Confirmatory factor analyses (CFAs) indicated that neither null nor 1-factor models of the EDI fit item-level or item-parcel data. The proposed 8-factor model did not fit at the item level but did fit item-parcel data. Reliability estimates of the 8 scales ranged from .82 to .93, and low-to-moderate interscale correlations among the eating and weight-related scales provided partial support for convergent validity. EDI personality scales showed moderate interscale correlations and were associated with MCMI-II scales. A final CFA of the EDI scales supported a 2-factor model (Eating and Weight, Personality) of the 8 EDI scales. Strong associations between depression and several EDI scale scores were found in a treatment study sample (n = 50). The archival clinic sample scored significantly higher on the 8 EDI scales than the nonpatient college comparison sample (n = 487).     

Mother Knows Best? Mother and Child Report of Behavioral Difficulties of Children of HIV-Infected Mothers

Children of HIV-infected mothers have more psychosocial adjustment difficulties than do those of noninfected mothers. In this study, child psychosocial adjustment in children of HIV-infected women is examined across the three stages of HIV-infected: asymptomatic, symptomatic and AIDS. Participants were 99 HIV-infected women and 148 noninfected women. Children were not identified as being HIV infected. Mother and child reports of behavioral difficulties are compared, and competing hypotheses about mother report of child behavior difficulties are tested. Results indicate an ascending linear trend for child report of internalizing and externalizing difficulties from the noninfected stage through increasingly severe stages of HIV-infection. According to mother report, child externalizing and internalizing difficulties are nonlinear, as mothers report an increase through the infected symptomatic stage, then a decrease in the AIDS stage. Implications for assessment, prevention and intervention in families with maternal HIV infection are discussed.     

Specialization of the motor system in infancy: from broad tuning to selectively specialized purposeful actions

In executing purposeful actions, adults select sufficient and necessary limbs. But infants often move goal‐irrelevant limbs, suggesting a developmental process of motor specialization. Two experiments with 9‐ and 12‐month‐olds revealed gradual decreases in extraneous movements in non‐acting limbs during unimanual actions. In Experiment 1, 9‐month‐olds produced more extraneous movements in the non‐acting hand/arm and feet/legs than 12‐month‐olds. In Experiment 2, analysis of the spatiotemporal dynamics of infants’ movements revealed developmental declines in the spatiotemporal coupling of movements between acting and non‐acting arms. We also showed that the degree of specialization in infants’ unimanual actions is associated with individual differences in motor experience and visual attention, indicating the experience‐dependent and broad functional nature of these developmental changes. Our study provides important new insights into motor development: as in cognitive domains, motor behaviours are initially broadly tuned to their goal, becoming progressively specialized during the first year of life.