17. 다음 글의 요지로 가장 적절한 것은?
In one study, done in the early 1970s when young people tended to dress in either “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; when the student and requester were dissimilarly dressed, the dime was provided less than half the time. Another experiment showed how automatic our positive response to similar others can be. Marchers in an antiwar demonstration were found to be more likely to sign the petition of a similarly dressed requester and to do so without bothering to read it first.
- 1People are more likely to help those who dress like themselves.

- 2Dressing up formally increases the chance of signing the petition.

- 3Making a phone call is an efficient way to socialize with other students.

- 4Some college students in the early 1970s were admired for their unique fashion.
