Several studies have demonstrated that we are more likely to help those who dress like us. In one study, done in the early 1970s when young people tended to dress either in “hippie” or “straight” fashion, experimenters donned hippie or straight attire and asked college students on campus for a dime to make a phone call. When the experimenter was dressed in the same way as the student, the request was granted in more than two thirds of the instances; but when the student and requester were dissimilarly dressed, the dime was provided less than half the time. Another experiment shows how automatic our positive response to similar others can be. Marchers in an antiwar demonstration were found to be not only more likely to sign the petition of a similarly dressed requester, but also to do so without bothering to read it first. Click, whirr.