(PhysOrg.com) -- Gorillas play competitive games like we do, helping to keep games going and even giving younger friends a fair chance, according to the latest research. The study, by psychologists at the University of St Andrews, helps trace the evolutionary origins of how humans understand each other.
Dr Joanne Tanner and Professor Richard Byrne watched gorillas at play to learn more about how apes are able to take account of each other's aims and abilities. The results trace the evolution of human ability to take the perceptions and goals of others into account, back to 6 million years ago.
The researchers watched gorillas play games involving balls, bags and leather pieces as the focus of attention, typically with play partners changing possession of a play object many times.
Professor Byrne commented, "Just like we would, the gorillas used gestures and displays of the object to keep the action going, and if the game slowed down or stopped a gorilla would use varied tactics to get it going again.
"The players were also considerate of others' abilities: an older and more skilled gorilla seeming to realise that if it used all of its potential, the younger one wouldn't be able to compete, so the older gorilla would slow down the pace."
This kind of shared activity and joint attention with another person begins around 9 months of age in humans. Although this process has been suggested to be unique to humans, there have been some previous signs that our closest relatives among the African great apes might also show similar abilities. As a result of the new study, scientists can map the evolution of this process back to the time that humans shared ancestry with gorillas, over 6 million years ago.
Dr Tanner added, "Though the age at which gorilla games begin may be later in gorillas than in humans, and may depend on the challenges and artefacts available in a particular group's habitat, gorillas definitely enjoy the same kind of sporting competition we do!"
The research is published by the journal Animal Cognition (January 2010)
Explore further: Biologists use unique tools to investigate squirrel sounds and gestures