The New York Times Science Section has an article on how easy it is to manipulate the little machines that lie at the heart of us.

In a recent experiment, psychologists at Yale altered people’s judgments of a stranger by handing them a cup of coffee.

The study participants, college students, had no idea that their social instincts were being deliberately manipulated. On the way to the laboratory, they had bumped into a laboratory assistant, who was holding textbooks, a clipboard, papers and a cup of hot or iced coffee — and asked for a hand with the cup.

That was all it took: The students who held a cup of iced coffee rated a hypothetical person they later read about as being much colder, less social and more selfish than did their fellow students, who had momentarily held a cup of hot java.

Scents, signage, and symbols can all act as little triggers, the article tells us. There’s no word on whether the scientists credit Elvis Costello for his early work on the subject.