Baby Chimpanzees play in a very similar way to human beings. They alternate diverse game phases human in the same way human infants do. This is the principle result of a study on game behaviour of a large species of Pan troglodytes , published in the scientific journal 'PloS ONE'. University of Pisa Research was carried out by Doctors Elisabetta Palagi and Giada Cordoni from the University of Pisa Natural History and Territory Museum in collaboration with the Institute of Science and Technology of Cognition at the CNR ( National Council for Research) in Rome. This project is included in the international socio-biological research that the Calci Museum has been conducting for many years.
This research is the result of observations that the researchers conducted in large European parks hosting many reproductive colonies. Over the long run these observations gave rise to data on 15 immature monkeys, infants and youths, allowing precise comparison of play in the diverse age phases. This study of Pisan researchers focussed principally on the analysis of parameters relating to social play when there are two or more animals. The results obtained demonstrated that there exist appreciable variations during the passage from the infant to the later youth stages in chimpanzees, as there are in man. In particular this research study reinforced the fact that solitary play and social play follow two ontogenetically different paths. While the former shows a peak frequency during infancy, the latter maintains reasonably constant levels during the entire immature phases. These differences are not only quantitative but also qualitative since the young chimps become more articulate (given the number of game patterns used in a session) and more balanced (given the modality and frequency these directional patterns are exchanged amongst the players).
The importance of this study resides in the fact that the data regarding non human primates were compared (in the standardised and precise way) with the data present in the literature on human game behaviour. What emerged was that like the baby chimps children of pre-school age, from 0 to 3 years, show very high levels of solitary game play and the frequency of the social game of wrestling remains reasonably constant. Both immature chimpanzees and Homo sapiens showed they prefer games with their playmates of the same age which, in adolescents of both species, becomes more balanced and complex, even if also more competitive.
Starting with the idea of a contestation of the close philogenetic association between Homo sapiens and other anthropomorphic monkeys, this research suggests that the behavioural confrontation among these species plays a crucial role for illuminating the biological bases of many behaviour patterns present in what we can call, from a zoological and evolutive point of view, the "animal-man".