Clever Apes: Testosterone drives a hard bargain

March 23, 2011

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Let’s talk a little bit about testosterone, shall we?

Sure, it’s a loaded topic, tied up with what behaviors are supposedly “male.” But of course both men and women have it, and it seems to play a big role in the kind of people we wind up becoming. Testosterone is considered an “organizing hormone,” meaning the amount of it present in the womb has lifelong effects on how a baby’s body and brain will develop.

Adam Galinsky is a psychologist at Northwestern University’s Kellogg Graduate School of Management. Being in the business school and all, he was curious how prenatal testosterone levels affect the way people act in a bargaining situation.

Listen to the interview with Adam Galinsky

Testosterone podcast (1).mp3

But before you can do that, you have to measure how much testosterone someone was swimming around in in the womb. This turns out to be pretty easy.

Prenatal testosterone correlates to ring and index finger lengths. Weird, right?

Look at your hand. If your ring finger is longer than your index finger, you probably had a lot of testosterone in your prenatal bathwater. If the two fingers are more equal, or if your index finger is longer, you had less. Now, consider that this hormone, which determined the structure of your digits, also has a big role in how your brain is built.

Galinsky says it appears that testosterone is uniquely associated with a sensitivity to status. So he designed an experiment to see how people at a negotiating table behave when they perceive an insulting offer. A subject (the “responder”) is told that another person (the “proposer”) has been given $40 and can choose how to divide it up between the two of them. Some of the responders are told they’ll be getting an unfairly low share – just $5. Next, the roles are reversed, and the study subject gets the money and gets to decide.

Here’s where the testosterone figures in. People with higher levels of prenatal testosterone were much more likely to retaliate with a low-ball offer, while lower-testosterone subjects were more likely to respond with a fair offer – even to the person who had just screwed them. So Galinsky says high testosterone seems to correlate with an aggressive response to losing face – though not necessarily to aggression more generally. And furthermore, the correlation holds for both men and women.

It seems to me that this means that before negotiating, you should photograph the hands of the person across the table from you. Measure those fingers – and you may learn a surprising amount about how that person’s brain works.

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