RESUMO

Perceived vocal attractiveness and measured sex-dimorphic vocal parameters are both associated with underlying individual qualities. Research tends to focus on speech but singing is another highly evolved communication system that has distinct and universal features with analogs in other species, and it is relevant in mating. Both speaking and singing voice provides relevant information about its producer. We tested whether speech and singing function as "backup signals" that indicate similar underlying qualities. Using a sample of 81 men and 86 women from Brazil and the Czech Republic, we investigated vocal attractiveness rated from speech and singing and its association with fundamental frequency (F0), apparent vocal tract length (VTL), body characteristics, and sociosexuality. F0, VTL, and rated attractiveness of singing and speaking voice strongly correlated within the same individual. Lower-pitched speech in men, higher-pitched speech and singing in women, individuals who like to sing more, and singing of individuals with a higher pitch modulation were perceived as more attractive. In men, physical size positively predicted speech and singing attractiveness. Male speech but not singing attractiveness was associated with higher sociosexuality. Lower-pitched male speech was related to higher sociosexuality, while lower-pitched male singing was linked to lower sociosexuality. Similarly, shorter speech VTL and longer singing VTL predicted higher sociosexuality in women. Different vocal displays function as "backup signals" cueing to attractiveness and body size, but their relation to sexual strategies in men and women differs. Both singing and speech may indicate evolutionarily relevant individual qualities shaped by sexual selection.

RESUMO

Cracking nuts with tools is a behavior documented in a small number of populations of tufted capuchins, mainly in semi-arid Caatinga and Caatinga-Cerrado transitional environments of northeastern Brazil. Only one of these populations inhabits the less arid Cerrado in Central Brazil, where environments are composed of a heterogeneous mosaic of fields, savannas and forest formations. We conducted surveys in 10 of 20 localities where nutcracking by capuchins was reported by the local inhabitants in the Cerrrado of Northern Goiás and Tocantins. Our purpose was to evaluate nutcracking sites (anvils and associated hammers and nuts) based on indirect evidence of extensive pounding of nuts and seeds. Nutcracking was confirmed at all 10 surveyed localities. A total of 270 sites were identified. Surveyed localities included areas that were ecologically similar to those where capuchins crack nuts in Caatinga, as well as less arid localities with more typical Cerrado habitat. Anvils and hammers were made of materials including quartz, limestone, sandstone and wood, and displayed a wider range of sizes (i.e., 60-3,750 g for hammers' weight) than reported at previously studied localities. Nuts of seven genera were found in association with anvils and hammers. We conclude that nutcracking by capuchins are not restricted to arid environments and argue that the occurrence and diversity of nutcracking tool sites result from complex interactions of environmental variables (e.g., availability of food and mineral resources, density of canopy cover) and social variables (e.g., spatial cohesiveness and tolerance among group members) that need to be examined through long-term research of habituated groups. Localities in the Cerrado of Northern Goiás and Tocantins vary considerable in the ecological conditions faced by wild groups, and therefore offer the opportunity to examine these interactions.

Assuntos

RESUMO

Investigamos a relação entre fatores de aprendizagem social, acessados via questionários, e os comportamentos agressivos e lúdicos de meninos pré-escolares, através de observação direta durante o recreio. Os participantes foram 15 meninos com idades entre quatro e seis anos, da cidade de Goiânia, GO, Brasil. Uma análise multivariada de variância indicou efeitos significativos de modelos de agressividade em casa nas taxas de agressão durante o brincar. Crianças expostas a punições físicas abusivas, brigas entre adultos e programas violentos de TV apresentaram mais agressões reais. Meninos que relataram brincar com armas de brinquedo em casa não apresentaram mais agressões reais do que os que relataram o contrário, mas apresentaram maior proporção de agressões de faz-de-conta. Os resultados também indicaram que quanto mais modelos agressivos em casa, maior a incidência de comportamentos agressivos.(AU)

We investigated the interaction between social learning factors measured by questionnaires and aggressive and playful behaviors of pre-school children, through direct observation during their playful break time. The subjects were 15 boys between four and six years old who were enrolled in a non-profit child care center in Goiânia-GO, Brazil. A multivariate analysis of variance indicated significant effects of aggressive models at home on aggression levels during playful behavior. Children exposed to abusive physical punishment, adult fighting and violent TV programs engaged in more episodes of aggression during playful breaks. Boys who reported to play with toy guns at home did not engage in aggressive behavior more often than those who did not, but they displayed a higher proportion of pretended aggression. Results also indicated that aggressive behavior becomes more frequent as the number of aggressive models at home increases.(AU)

Assuntos

RESUMO

Investigamos a relação entre fatores de aprendizagem social, acessados via questionários, e os comportamentos agressivos e lúdicos de meninos pré-escolares, através de observação direta durante o recreio. Os participantes foram 15 meninos com idades entre quatro e seis anos, da cidade de Goiânia, GO, Brasil. Uma análise multivariada de variância indicou efeitos significativos de modelos de agressividade em casa nas taxas de agressão durante o brincar. Crianças expostas a punições físicas abusivas, brigas entre adultos e programas violentos de TV apresentaram mais agressões reais. Meninos que relataram brincar com armas de brinquedo em casa não apresentaram mais agressões reais do que os que relataram o contrário, mas apresentaram maior proporção de agressões de faz-de-conta. Os resultados também indicaram que quanto mais modelos agressivos em casa, maior a incidência de comportamentos agressivos.

We investigated the interaction between social learning factors measured by questionnaires and aggressive and playful behaviors of pre-school children, through direct observation during their playful break time. The subjects were 15 boys between four and six years old who were enrolled in a non-profit child care center in Goiânia-GO, Brazil. A multivariate analysis of variance indicated significant effects of aggressive models at home on aggression levels during playful behavior. Children exposed to abusive physical punishment, adult fighting and violent TV programs engaged in more episodes of aggression during playful breaks. Boys who reported to play with toy guns at home did not engage in aggressive behavior more often than those who did not, but they displayed a higher proportion of pretended aggression. Results also indicated that aggressive behavior becomes more frequent as the number of aggressive models at home increases.

Assuntos