Hello Dolly!

Posted on January 13, 2011


Tomorrow is my birthday and it’s true that the years seem to speed up as I get older. How did I get to be this age? (21 again in case you’re wondering).

When the Northerner asked me what I wanted for my birthday I was remarkably restrained, and told him a nice day with a lovely dinner and more regular work shifts please – it’s the simple things in life.

But when I think back to my childhood, every birthday was like Santa’s grotto – presents galore. I was definitely spoilt by my doting parents. Not in a brat-ish way, mind you, but Mum and Dad tried their best to give my brother and I whatever was on our wish list. He always got the latest gizmos and I always got a new dolly.

How we play with toys as children, could be down to genetic hard-wiring, rather than social influence from our surroundings. This is a particularly controversial issue as many experts are divided on the subject. But evidence has emerged that points towards this. It’s part of a 14-year study into chimpanzees (Pan troglodytes) in East Africa and how they “play” with sticks.

Infant chimpanzees have been seen "playing with sticks" in Kibale National Park.

Primatologists have discovered that young female chimpanzees in Kibale National Park in Uganda, carry and cradle sticks like toys, in the same way that children do. But depending on gender, they “play” differently with their “toys”.

The findings by Sonya M. Khalenberg of Bates College in Maine and Richard W. Wrangham of Havard University, found that females carried the sticks like dolls, until they had offspring of their own; and that young males did this less frequently, but played with sticks as toy weapons.

We share more than 98 per cent of our DNA with chimpanzees, they are our closest living relative. Our genes are so similar we’d be able to receive a blood-transfusion from these great apes. On-going scientific research into chimpanzee behaviour aims to help anthropologists discover more about our common ancestors dating back around 5 million years ago and how we evolved into modern man.

The evidence also sheds light on the first known difference in wild male and female chimpanzees’ choice of playthings. And it suggests that biological factors – rather than social influences alone – affect the way that human infants play with toys.

Professor Wrangham said, “What we’ve got here is evidence that without any kind of socialisation by adults, females seem to be predisposed to react to sticks as though they were dolls.

“Like children and captive monkeys, this behaviour is more common in females than in males.”

The young chimps apparently learned their play styles from each other, as their parents did not play with sticks, say the authors, “Such juvenile traditions have previously been described only in humans.

“Obviously, in humans there is a huge role for peers, parents, and others to influence a child’s preferences for different kinds of toys, and the same may well be true of chimpanzees.”

Some young chimpanzees carried sticks into their nests to sleep with them, and on one occasion built a separate nest for the stick. The researchers even witnessed the animals playing a version of the “airplane game,” lying on their backs with their pretend “offspring” balanced across their upraised hands.

Professor Wrangham added, “One of the things that makes our finding fascinating is that there is little evidence of anything comparable in other chimpanzee communities, which raises the possibility that the chimpanzees are copying a local behavioural tradition. So this may be a lovely case of biological and social influences being intertwined.”

I’m celebrating my birthday this weekend and as I don’t have any “offspring” of my own, this is a polite message to some of my friends who have an odd sense of humour (you know who you are!). Please don’t bring any sticks to my party.

[Anyone interested in reading the published scientific journal can find it in Current Biology]

Kahlenberg and Wrangham’s research was supported by National Science Foundation; The Leakey Foundation; the National Geographic Society, the Getty Foundation, and the Wenner-Gren Foundation.