Albrecht et al (2006) showed how having a non-smoking 'buddy' helps young people resist smoking.
Gamson et al (1982) showed how peer support can lead to disobedience, undermining the legitimacy of authority.
Allen & Levine (1971) showed that socialsupport can help individuals resist group influence. In an Asch-like task only 3% resisted when there was no support.