To kill bias, gather good data

I hate myself for this: I have the worst sense of direction.

For the entire year when I was living in my first apartment in Kingston, I would take a circuitous route along King Street and then up Princess on my way home from the Kingston Yacht Club. Nearly two kilometers, when walking up West Street would have got me home in half the time. As Charlie said when I revealed this to him, “Two sides of a triangle is always greater than one.”

It’s not that I didn’t know grade school geometry, or that I wanted a more scenic route. I just stuck to the path I knew would get me there.

I felt a bit triumphant when I realized how long it can take Charlie when you ask him to pick up the milk. The last time I dragged him to the grocery store, I left him alone for a few minutes to use the bathroom, and returned to find him loading pineapple after pineapple after pineapple – painfully slowly, into the cart. We laughed, but I don’t ask him to come with me anymore. Alone, I can collect a week’s worth of food in less than 20 minutes.

I’m not ashamed to admit my navigational failings, either. My field assistant Myra and I happily agreed that our best strategy driving around Los Angeles was that we should always do the opposite of whatever we both thought was correct. It worked.

What I hate is my sneaking suspicion that I’m just a lame stereotype. Maybe I’m a terrible navigator because of biology; female brains are just not suited for getting around.

Hunter, gatherer

Modified from this cartoon. Original source unknown.

Recently, psychologists looked at this sex difference in what seemed like a neat field study of human foraging behaviour – in a grocery store1. Joshua New from Yale University, and his coauthors from UC Santa Barbara, set up a unique experiment in a California farmers’ market: they led men and women around the market, giving them samples like apples, fennel, almonds and honey. Then they brought the subjects back to a central location and asked them to point in the direction of those same food items.

These researchers wanted to test the idea that women outperform men at certain kinds of spatial tasks: while men are thought to be better at vector-based navigation, women might excel at remembering the locations of objects, because of the way foraging roles were divided up when our brains were evolving. It’s thought that in our hunter-gatherer past, big game hunting meant that men had to figure out how to bring heavy prey home by the most direct route. Women foraging closer to home needed a much different set of spatial adaptations2. It’s not that men are better at spatial reasoning in general, you just have to choose the right task3.

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