In this paper we present evidence for female mimicry in a population of Salaria pavo (Pisces: Blenniidae). Parental males differ markedly from females by the presence of a large crest on the head and anal glands on the two spiny rays of the anal fin. We found a proportion of smaller and younger males that are almost identical to females both in morphology and behaviour. These 'female-like' males lack secondary sexual characters and actively court parental males, displaying the female's colour pattern and courting behaviour. These males are sexually mature and their gonadosomatic indices are higher than those of parental males. Female mimicry is considered to be a functional way to achieve sneak fertilizations.

The generality of a multilevel factorial model of social competence (SC) for preschool children was tested in a 5-group, multinational sample (N = 1,540) using confirmatory factor analysis. The model fits the observed data well, and tests constraining paths for measured variables to their respective first-order factors across samples also fit well. Equivalence of measurement models was found at sample and sex within-sample levels but not for age within sample. In 2 groups, teachers' ratings were examined as correlates of SC indicators. Composites of SC indicators were significantly associated with both positive and negative child attributes from the teachers' ratings. The findings contribute to understanding of both methodological and substantive issues concerning SC in young children.

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Changes in affiliative organization of 15 age-graded toddler and preschool play groups were examined in terms of assessed similarity in patterns of playmate association. Measures of peer association were derived from direct observation of social interaction during free play. The degree of between subject similarity in association profiles was derived using complete linkage hierarchical clustering procedures. Findings revealed distinct social subgroups in all social groups. Secondary analyses showed a linear increase in the size of affiliative subgroups as a function of age. Measures of interactive reciprocity within social subgroups suggested progressive consolidation of affiliative structures with age. Among older children, membership within affiliative subgroups was associated with more frequent preferences for subgroup members. Findings are discussed in terms of how children's insertion within the affiliative network of their peer group constrain socialization of their behavior and provide specific experiences that serve as contexts for the construction of more intimate interpersonal relationships.Contemporary research in social ethology examines both aggressive and cooperative activities from a dynamic perspective emphasizing contextual constraints imposed by the structuring of interpersonal relationships within the stable social group. John Crook (1970) was one of the first behavioral biologists to propose that differences in individual adaptation are modulated by the social structure of a stable group. In his distinction between classical and social ethology, Crook stressed that variation in individual behavior must be understood in terms of We gratefully acknowledge the contribution of the children, parents and staff at 'La Garderie La Sourith^que' for their active participation in our research. Special thanks are also due to students and colleagues who served as members of the different observational teams charged with primary data collection. Finally, we thank colleagues from the Research Group on Peer Networks -Teresa Blicharski,

The secure-base phenomenon is central to the Bowlby/Ainsworth theory of attachment and is also central to the assessment of attachment across the lifespan. The present study tested whether mothers' knowledge about the secure-base phenomenon, as assessed using a recently designed wordlist prompt measure for eliciting attachment-relevant stories, would predict their children's securebase behavior, as assessed by observers in the home and summarized with the Attachment Q-set (AQS). In each of three sociocultural groups (from Colombia, Portugal, and the US), scores characterizing the quality of maternal secure-base narratives elicited using the word-list prompt procedure were internally consistent, as indicated by tests of cross-story reliability, and they were positively and significantly associated with the child's security score from the AQS for each subsample. The correlation in the combined sample was r(129) = .33, p < .001. Subsequent analyses with the combined sample evaluated the AQS item-correlates of the secure-base script score.These analyses showed that mothers whose stories indicate that they have access to and use a positive secure-base script in their story production have children who treat them as a “secure base” at home. These results suggest that a core feature of adult attachment models, in each of the three sociocultural groups studied, is access to a secure-base script. Additional results from the study indicate that cross-language translations of the maternal narratives can receive valid, reliable scores even when evaluated by non-native speakers.

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The purpose of this study was to compare the effects of an 8-week training period of resistance training alone (GR), or combined resistance and endurance training (GCOM), followed by 12 weeks of detraining (DT) on body composition, explosive strength, and ·VO₂max adaptations in a large sample of adolescent school boys. Forty-two healthy boys recruited from a Portuguese public high school (age: 13.3 ± 1.04 years) were assigned to 2 experimental groups to train twice a week for 8 weeks: GR (n = 15), GCOM (n = 15), and a control group (GC: n = 12; no training program). Significant training-induced differences were observed in 1- and 3-kg medicine ball throw gains (GR: +10.3 and +9.8%, respectively; GCOM: +14.4 and +7%, respectively), whereas no significant changes were observed after a DT period in both the experimental groups. Significant training-induced gains in the height and length of the countermovement (vertical-and-horizontal) jumps were observed in both the experimental groups. No differences were perceived after a DT period in lower limb power. Time at 20 m decreased significantly for both intervention programs (GR: -11.5% and GCOM: -12.4%, <0.00), but either GR or GCOM groups kept the running speed after a DT period of 12 weeks. After training, the ·VO₂max increased only significantly for GCOM (4.6%, p = 0.01). A significant loss was observed after a DT period in GR but not in GCOM. Performing resistance and endurance training in the same workout does not impair strength development in young school boys. As expected, strength training by itself does not improve aerobic capacity. Our results also suggest that training program effects even persist at the end of the DT period.

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