The Animal Module

by F.

I’m not sure how much more mileage this “mental module” metaphor is good for, but it shows few signs of wear and tear. The latest example comes from Joshua New. The Economist discusses his latest paper (coauthored with Cosmides and Tooby):

Which is more dangerous, an elephant or a minivan? For most readers of this newspaper, the answer is going to be a minivan. From childhood, people in motorised civilisations are warned about the dangers of running into the road, taught the appropriate highway code and—when old enough—permitted to get behind the wheel only after having undergone a rigorous programme of training that ends with a formal examination.

You might think, therefore, that such people would be more aware of the movements of vehicles than of animals. But if you did think that, you would be wrong. An experiment just published in the Proceedings of the National Academy of Sciences by Joshua New of Yale University shows that people pay more attention to the activities of animals than to those of vehicles. That applies even among urban Westerners who rarely see an animal from one year’s end to the next

UCSB summarizes the research this way:

Recent experiments show that the visual priorities of our hunter-gatherer ancestors are embedded in the modern brain. What our eyes look at is guided by brain mechanisms that pick out some portions of a scene over others. Since keeping an eye on predators and prey was important during our evolution, Joshua New and colleagues investigated whether animals, both human and otherwise, are more likely to draw visual attention spontaneously. The researchers showed subjects pairs of photographs of natural scenes in rapid alternation, with the second photograph including a single change.

As predicted, subjects were faster and more accurate detecting changes involving animals than inanimate objects. If experience were producing this attentional bias for animals, then people should also be good at detecting changes to vehicles—they have been trained all their lives, as drivers and pedestrians, to monitor vehicles for sudden, life-or-death changes in trajectory. Yet they were much slower in detecting changes to vehicles than to more rarely experienced animal species, indicating that learning is not the source of this difference. The bias for animals, the authors conclude, is like the appendix—present in modern humans because it was useful for our ancestors, even if useless now.

The paper is here.

[composed and posted with ecto]