Comments on: Do young female chimps play with sticks as dolls?

By: praisegod barebones

praisegod barebones — Fri, 24 Dec 2010 15:24:31 +0000

I’m a bi9t disappointed that the thing that’s attracting all the attention here is the gender difference stuff. From my perspective (one of the things I work on is Theory of Mind) the fact that we’ve got something that looks like pretend-play in a non-human species is the really stunning thing about this.

By: EMJ

EMJ — Tue, 21 Dec 2010 20:16:10 +0000

Great review of the paper Ed!

This behavior would need to be found in multiple other colonies for it to be considered species-typical behavior. However, in our species girls playing with dolls as a form of maternal practice is the norm in many different societies (perhaps even most) and there continues to be disagreement over whether it represents innate sex differences.

By: Michael Meadon

Michael Meadon — Tue, 21 Dec 2010 11:29:56 +0000

Oh, and David, is this the study Spelke was talking about? (There are a couple of similar looking papers to be found here).

By: Michael Meadon

Michael Meadon — Tue, 21 Dec 2010 11:24:33 +0000

Excellent write-up, Ed.

While this probably cannot be done for fear of ‘contaminating’ the Kanyawara chimp’s culture, it would be interesting to replicate the monkey study you reference by providing the chimps with human toys. Perhaps this kind of thing COULD be done with captive chimps.

@David: awesome comment. That study Spelke described is incredibly interesting indeed. Reminds me of the following John Stuart Mill quote (from The Subjection of Women) :

“I deny that anyone knows, or can know, the nature of the two sexes, as long as they have only been seen in their present relation to one another. If men had ever been found in society without women, or women without men, or if there had been a society of men and women in which the women were not under the control of the men, something might have been positively known about the mental and moral differences which may be inherent in the nature of each. What is now called the nature of women is an eminently artificial thing — the result of forced repression in some directions, unnatural stimulation in others.”

By: David Dobbs

David Dobbs — Mon, 20 Dec 2010 22:05:55 +0000

Nice write-up, Ed. This is tricky territory indeed. When you mentioned the studies showing that boys and girls play differently even at a few weeks or months old, I was reminded of a study that infant-cognition researcher Liz Spelke (who once debated Steven Pinker on the issue of possibly inherent gender differences in behavior) told me about. I don’t recall the study itself so can’t give a reference. But as she described it, the study observed people, both men and women, as they were given a baby to play with — and the way that people played with this very young infant would vary sharply and predictably depending on whether the infant was dressed as a boy or as a girl: if as a boy, they would be much more physical with the baby, bouncing the baby more, etc., and if it was a girl, they would more gentle physically, with more cuddling and a higher level of baby talk. This was seen in both women and men, and the actual gender of the infant (for the study used both boys and girls) didn’t matter.

Spelke told this story to make the point that we treat babies very differently depending on gender from a very early age, and that this enough might be enough to generate different behaviors in the two genders. I don’t know the rest of the literature all that well. But this story seems to speak to the point about the early differences in play preferences.

Ah: I easily found the debate Spelke had with Pinker. It’s at http://www.edge.org/3rd_culture/debate05/debate05_index.html. I’m not sure if she mentions the study in it but I suspect she might.

Readers who find Spelke intriguing — which she very much is — might be interested in either my profile of her (http://daviddobbs.net/page2/page3/page3.html) or one that appeared in the New Yorker not long after (http://www.newyorker.com/archive/2006/09/04/060904fa_fact_talbot).

By: KBHC

KBHC — Mon, 20 Dec 2010 21:51:08 +0000

Thanks, Ed! That’s interesting about wiping — I do remember the weapon stuff but otherwise thought females were the ones who used tools a lot more.

Either way, it’s certainly a very cool data set, from some successful and smart scholars.

By: Ed Yong

Ed Yong — Mon, 20 Dec 2010 21:07:44 +0000

@KHBC – Great comment. The authors do mention that females reportedly use objects more often than males but they note that this doesn’t occur across the board. Males are more likely to use weapons, and to use leaves for wiping themselves. So one can’t say that females use all objects more frequently.

Like you, I have no reason to doubt the interpretation of stick-carrying as analogous to doll-play, but I don’t quite buy the “ancient sex differences” suggestion.

By: KBHC

KBHC — Mon, 20 Dec 2010 20:11:56 +0000

First, I’ll say that I think this material is really interesting and I trust the study co-authors have observed a robust finding. However, I’m hesitant to link this to an ancient sex difference. We’ve seen cultural differences among different populations of chimps, related to how much hunting they do, how territorial they are, and the types of tools they use. This could have been transmitted within this population over the years because one female chimp did it. Seeing female chimps do something more than male chimps that is tool-related is also not surprising: my understanding (though I’m not the flavor of biological anthropologist who does behavior) is that female chimps in general use tools more than male chimps, and that young female chimps seem much more interested than their brothers in copying their mothers. (Please correct me if I’m wrong, but I am fairly certain I’ve both read this and heard this from my colleagues.) So, if female chimps are more likely to manipulate objects and use them as tools, it makes sense they would also sometimes use them as toys or use them to imitate their others.

To me, the stronger sex difference that is re-affirmed by this data is that females use objects as tools more often than males, within chimps. I would still hesitate to say that this difference is meaningful beyond the environmental/social factors that produce it: chimps have female philopatry, males are related and bonded, so males probably put more stock into building and maintaining their relationships and hierarchies. Females might spend more time figuring out how to get as many calories as possible, and spend time learning from their mothers so that they can do the whole mothering thing later in life. I don’t think an “ancient sex difference” is necessary to explain this.