A recent article by Sy Montgomery in the Boston Globe illustrates some of the dangers of anthropomorphism, the attribution of human characteristics to nonhumans. As an animal behavior researcher, discussing anthropomorphism can feel like walking a tightrope.
Most of the time, I work hard to convince people (from students to program officers) that human behavior is animal behavior. I don't study pigeons because I want to learn about pigeons, I study pigeons because I want to learn about behavior. The laws that govern their behavior are the same as the laws that govern ours. Differences between humans and other animals, as Darwin put it, are differences of degree and not of kind.
Why, then, is anthropomorphism a problem? Why don't similar facial expressions, noises and movements mean the same thing to different species? For the same reason the American hand gesture for "peace" looks very similar to a gesture that communicates "up yours" across the pond: similar responses were selected by very different consequences in different, but similar, environments. Anthropomorphism is nothing more or less than a cultural blunder on an evolutionary timescale.
Quantitative analyses of behavior involve describing, forecasting and explaining behavior using mathematical equations. This approach can generate very accurate, precise descriptions of behavior. It makes objective comparison of different explanations possible. Sometimes, models generate surprising predictions and explain things you would not expect from verbal descriptions alone!