Acquisition of joint attention by olive baboons gesturing toward humans

Animal Cognition - Joint attention is a core ability of human social cognition which broadly refers to the coordination of attention with both the presence and activity of social partners. In both...     

Where have all the (ape) gestures gone?

Comparative analysis of the gestural communication of our nearest animal relatives, the great apes, implies that humans should have the biological potential to produce and understand 60–70 gestures, by virtue of shared common descent. These gestures are used intentionally in apes to convey separate requests, rather than as referential items in syntactically structured signals. At present, no such legacy of shared gesture has been described in humans. We suggest that the fate of “ape gestures” in modern human communication is relevant to the debate regarding the evolution of language through a possible intermediate stage of gestural protolanguage.     

Relationships between declarative pointing and theory of mind abilities in 3- to 4-year-olds

The current study explored the relationships between declarative pointing and theory of mind abilities in 30 children between 3 and 4 years of age. Measures used to examine theory of mind (ToM) included a parental questionnaire and the Scaling of Theory of Mind Tasks. Results showed a dissociation between expressive and informative pointing, which have been regarded as two subcategories of the declarative function. ToM abilities were significantly related to the production of informative pointing, but not to the production of expressive pointing. This distinction might be explained by special features associated with informative pointing, such as early signs of cooperation abilities. Our results might have key implications for psychologists, as they may help improve evaluation and intervention programs for the development of social skills in preschoolers.     

Hand preference for pointing gestures and bimanual manipulation around the vocabulary spurt period

This study investigated the development of hand preference for bimanual manipulative activities and pointing gestures in toddlers observed longitudinally over a 5-month period, in relation to language acquisition. The lexical spurt was found to be accompanied by an increase in the right-sided bias for pointing but not for manipulation. Moreover, results revealed a significant correlation between hand preference for imperative pointing gestures and manipulative activities in children who did not experience the lexical spurt during the observational period. By contrast, measures of handedness for declarative pointing were never correlated with those of handedness for manipulation. This study illustrates the complex relationship between handedness and language development and emphasizes the need to take the different functions of pointing gestures into account.     

Altruistic behavior and the bidimensional just world belief

Thirty participants were sampled after donating charity to a street beggar and were compared by means of 2 short scales of belief in ajust world for self (BJWS) and belief in a just world for others (BJWO) with 30 randomly selected people who passed the beggar by without donating charity. We assumed that BJWO would be negatively related to altruistic behavior, whereas BJWS would be positively linked with it. A logistic regression analysis introducing BJWS, BJWO, and participants' age and gender as predictors showed that BJWO was negatively related to altruistic behavior, whereas the BJWS tended to be positively associated to it. No effects were observed for age or gender.     

Evolutionary origins of human handedness: evaluating contrasting hypotheses

Variation in methods and measures, resulting in past dispute over the existence of population handedness in nonhuman great apes, has impeded progress into the origins of human right-handedness and how it relates to the human hallmark of language. Pooling evidence from behavioral studies, neuroimaging and neuroanatomy, we evaluate data on manual and cerebral laterality in humans and other apes engaged in a range of manipulative tasks and in gestural communication. A simplistic human/animal partition is no longer tenable, and we review four (nonexclusive) possible drivers for the origin of population-level right-handedness: skilled manipulative activity, as in tool use; communicative gestures; organizational complexity of action, in particular hierarchical structure; and the role of intentionality in goal-directed action. Fully testing these hypotheses will require developmental and evolutionary evidence as well as modern neuroimaging data.