Just Like Humans; Animal personality is now taken seriously.

Byline: Jessica Bennett

We name them, raise them, clothe them and spoil them. We describe them as manipulative, grumpy, sensitive and caring. And they're not even human--they're our pets. It's in our nature to ascribe human characteristics to animals even if they don't really exist. For this reason, in the interests of remaining objective observers of nature, scientists have taken pains to avoid anthropomorphizing animals. To talk about a dog's having a swagger or a cat's being shy would invite professional sneers.

In recent years, however, evidence has begun to show that animals have personalities after all. Chimps, for example, can be conscientious: they think before they act, they plan and they control their impulses, says Samuel Gosling, a Texas-based psychologist. Research has identified similar personality traits in many other species.

The implications of these findings for research on human personality are powerful. Scientists can look to animal studies for insight into humans the same way they now look to animal testing for insight into drugs. Animal research has already begun to shed light on how different types of people respond to medications and treatments--aggressive and passive rats respond differently to antidepressants, for example. The hope is that animals can illuminate the murky interplay of genes and the environment on people's personalities. The research may even lead to predictions about what people will do, based on their personalities, when they're stressed out or frightened. Putting personality testing--already a thriving business--on a firm footing could uncover a wealth of knowledge about where personality comes from.

Ivan Pavlov did his famous work with dogs in the early 1900s, but animal-personality studies then languished for decades. Now the field is making a comeback. In one study of fruit flies, researchers in the North Carolina State University genetics department found some flies to be consistently more aggressive than others--they made more threats and dished out more physical abuse, going so far as to kick and push others (yes, flies can kick). Similarly, research from the University of Guelph, in Ontario, looked at differences in rainbow trout; they found some to be ...