The findings on peer pressure were surprising to the researchers, HealthDay reports. “We thought friends would have more influence on cigarette use during high school than junior high school,” said study author Yue Liao. “But what we found was friends have greater influence during junior high school than high school. We think the reason may be that friends’ cigarette use behavior may have a stronger influence on youth who start smoking at a younger age,” she noted in a press release. “During high school, cigarette use might represent the maintenance of behavior rather than a result of peer influence.”