Behavior: Type A Minus

Type-A people, Americans have been taught to believe, are the competitive, impatient and hostile individuals who are prime candidates for heart attacks. But after 25 years, that portrait turns out to be highly debatable. At a May 9-10 conference at the University of Kansas, behavioral and medical scientists reached no agreement on whether the subject of the meeting, the Type-A behavior pattern, still exists. "We're all struggling," said Psychologist Larry Scherwitz of the University of California at San Francisco. "We have a concept that's not working. We're trying to find out what's wrong."

According to Scherwitz, six major research programs have...