Application of piecewise hierarchical linear growth modeling to the study of continuity in behavioral development of baboons (Papio hamadryas)

In behavioral science, developmental discontinuities are thought to arise when the association between an outcome measure and the underlying process changes over time. Sudden changes in behavior across time are often taken to indicate that a reorganization in the outcome-process relationship may have occurred. The authors proposed in this article the use of piecewise hierarchical linear growth modeling as a statistical methodology to search for discontinuities in behavioral development and illustrated its possibilities by applying 2-piece hierarchical linear models to the study of developmental trajectories of baboon (Papio hamadryas) mothers' behavior during their infants' 1st year of life. The authors provided empirical evidence that piecewise growth modeling can be used to determine whether abrupt changes in development trajectories are tied to changes in the underlying process.     

Ethnic/racial differences in the coming-out process of lesbian, gay, and bisexual youths: a comparison of sexual identity development over time

This longitudinal report of 145 lesbian, gay, and bisexual (LGB) youths examined ethnic/racial differences in the coming-out process. No significant differences emerged in sexual developmental milestones, sexual orientation, sexual behavior, or sexual identity. However, Black youths reported involvement in fewer gay-related social activities, reported less comfort with others knowing their sexual identity, and disclosed that identity to fewer people than did White youths. Latino youths disclosed to fewer people than did White youths. Analyses of change indicated Black youths had greater increases in positive attitudes toward homosexuality and in certainty in their sexual identity over time than did White youths. These findings support the authors' hypothesis that cultural factors do not impede the formation of identity but may delay identity integration.     

Deculturation: its lack of validity

Deculturation's history as well as its use in the social science literature is reviewed and its construct validity questioned. According to J. W. Berry (1980), deculturation results when members of nondominant cultures become alienated from the dominant culture and from their own minority society. A reported consequence of deculturation is increased stress and psychopathology for the individuals involved. Deculturation's basic assumption that there can be culture loss without replacement is critically assessed. In particular, the idea that members of nondominant groups can become deculturated, devoid of any culture, is challenged.     

Comparison of several shortened versions of the EMBU: exploratory and confirmatory factor analyses

The aim of the present study was to analyze the psychometric properties of different versions of the EMBU (Egna Minnen av Barndoms Uppfostran – My memories of upbringing) in a non-clinical sample of adolescents. The factor structure of the questionnaire was studied by means of more adequate exploratory and confirmatory factor procedures in order to ascertain which version achieves a better fit to data. The 64-item version of the EMBU was administered to a non-clinical sample of 832 adolescents. Exploratory and Confirmatory factor analyses were carried out for successive versions of 64, 37, 24 and 23 items. The theoretical four-factor structure of the 64-item version is not replicated in a factor analysis through principal axis extraction with direct oblimin rotation. The "Favoring Subject" factor was not found. 37 items present loadings equal to or larger than 0.30 for the "Rejection", "Emotional Warmth" and "Overprotection" factors. A re-analysis of these items shows a clear three-factor structure. When Arrindell et al .'s (1999 ) 23-item version was analysed, the three expected factors were also found. Confirmatory factor analyses allow us to reduce the 36-item version to a shorter one of 24 items. This last version achieves the best fit to data, including the 23-item version. The new 24-item version improves the construct validity of the EMBU and presents similar reliability coefficients.     

Bicuculline infusion into the accessory olfactory bulb facilitates the induction of maternal behavior in rats

The GABAA antagonist bicuculline, intracranially infused into the accessory olfactory bulb (AOB), facilitated the expression of maternal behavior (MB) in virgin Wistar female rats. Behavioral effects were observed 24 hours after infusion and were injection dependent. Pheromonal stimuli, generated by the pups, are thought to exert an inhibitory effect on vomeronasal nuclei involved in MB in virgin rats. The present study investigated the possibility that a decrement in AOB output, resulting from long-term compensatory synaptic changes to chronic bicuculline infusion, would facilitate the expression of MB. The implications of our findings for the mechanisms involved in the induction of MB and the maternal experience effect are discussed.     

Is there any relationship between sexual attraction and gender typology?

People can be classified as attracted to both sexes, to men, to women, or to neither sex, and also as instrumental-expressive, instrumental, expressive, or non-instrumental-expressive. The two hypotheses tested herein are, on the one hand, the relative independence between these two typologies and, on the other, the close relation between sexual dimorphism and sexual attraction, in contrast to the relative independence between sexual dimorphism and the instrumental and expressive domains. A total of 503 university students (284 women and 219 men) completed two assessment instruments: The Sexual Attraction Questionnaire (SAQ) and the Bem Sex Role Inventory (BSRI, 12 items). Analysis of contingency tables was performed. The results provide empirical support for the hypothesis of independence of the two typologies, solid support for the relation between sexual dimorphism and sexual attraction, and clear support for the independence between the gender domains and sexual dimorphism. The implications of these data for the different outlooks concerning the relations between sex and gender are established.     

Is sexual attraction independent of the instrumental and expressive traits?

Sexual attraction is an essential part of sex, just as the instrumental and expressive traits are the mainstay of gender. Various hypotheses concerning the dimensionality and independence versus dependence/overlapping of these core entities were tested. A group of 423 university students completed the Sexual Attraction Questionnaire (SAQ; Fernández, Quiroga, and Rodríguez, 2006) and the 12-item Bem Sex Role Inventory (BSRI; Bem, 1974). Internal consistency and factor analyses (PAF) were conducted. The results support the dimensionality established for the SAQ and reveal some psychometric and conceptual weaknesses of the 12-item BSRI. The results also support the independence of the two cores: sexual attraction and the instrumental and expressive traits. The logical implications for the different viewpoints of the relations between sex and gender are discussed.     

Does the mastery of center-embedded linguistic structures distinguish humans from nonhuman primates?

In a recentScience article, Fitch and Hauser (2004; hereafter, F&H) claimed to have demonstrated that cotton-top tamarins fail to learn an artificial language produced by a phrase structure grammar (Chomsky, 1957) generating center-embedded sentences, whereas adult humans easily learn such a language. We report an experiment replicating the results of F&H in humans but also showing that subjects learned the language without exploiting in any way the center-embedded structure. When the procedure was modified to make the processing of this structure mandatory, the subjects no longer showed evidence of learning. We propose a simple interpretation for the difference in performance observed in F&H’s task between humans and tamarins and argue that, beyond the specific drawbacks inherent in F&H’s study, researching the source of the inability of nonhuman primates to master language within a framework built around Chomsky’s hierarchy of grammars is a conceptual dead end.     

Temporal processing and phonological impairment in dyslexia: effect of phoneme lengthening on order judgment of two consonants

The evidence of supporting phonological deficit as a cause of developmental dyslexia has been accumulating rapidly over the past 2 decades, yet the exact mechanisms underlying this deficit remain controversial. Some authors assume that a temporal processing deficit is the source of the phonological disorder observed in dyslexic children. Others maintain that the phonological deficit in dyslexia is basically linguistic, not acoustic, in nature. Three experiments were conducted and tested the impact of the temporal alteration and the impact of complex syllabic structure on consonant order judgments. Thirteen phonological dyslexics (age 10-13) and 10 controls matched for chronologial age were compared on a Temporal Order Judgment (TOJ) task using the succession of two consonants (/p/ /s/) within a cluster. In order to test the possible relevance of the temporal deficit hypothesis, the task also included two additional conditions where either the two stimuli were artificially slowed or two phonological structures were opposed (CCV and CVCV). As expected, the TOJ performance was significantly poorer in dyslexics than in controls. Moreover, in the "slowed speech" condition dyslexics' performance improved to reach the normal controls' level, whereas manipulating the phonological structure complexity provided no significant improvement. Finally dyslexics' performances, especially on the slowed condition, were found correlated with several tests of phonological processing. These results lend support to the general temporal deficit theory of dyslexia.