Friend influence in adolescence is well-documented, but the characteristics that contribute to individual differences in susceptibility to influence are not well understood. The present study tests the novel hypothesis that within a friend dyad, having fewer friends than one’s partner (i.e., relative lack of alternatives) increases susceptibility to influence as it reduces dissimilarity and thereby promotes compatibility. Drawn from diverse California (USA) public middle schools, participants were 678 adolescents (58% girls) in reciprocated friendships that were stable from the fall to the spring of sixth grade (M = 11.53 years old). Longitudinal Actor-Partner Interdependence Models assessed peer influence, operationalized as individual change in the direction of increased friend similarity. Consistent with the hypothesis, partners with fewer friends were influenced by partners with relatively more friends in self-reported social anxiety and somatic complaints, as well as teacher-reported academic engagement and prosocial behavior. Academic engagement was the only domain wherein partners with more friends were also influenced by partners with relatively fewer friends. For those with few friends, conformity (i.e., becoming more similar to a partner) can be an important strategy to promote compatibility for strengthening existing friendships.

朋友在青春期的影响是有据可查的，但导致影响易感性的个体差异的特征尚不清楚。本研究检验了一个新的假设，即在朋友二元组中，朋友比伴侣少（即，相对缺乏替代品）会增加对影响的敏感性，因为它减少了差异性，从而促进了兼容性。来自加利福尼亚州（美国）不同的公立中学，参与者是 678 名青少年（58% 是女孩），他们在六年级的秋季到春季保持稳定的互惠友谊（M = 11.53 岁）。纵向演员-合作伙伴相互依存模型评估同伴影响，作为个人在增加朋友相似性方向上的变化而运作。与假设一致，朋友较少的伙伴在自我报告的社交焦虑和躯体投诉以及教师报告的学业参与和亲社会行为方面受到朋友相对较多的伙伴的影响。学术参与是唯一一个朋友多的伙伴也会受到朋友相对较少的伙伴影响的领域。对于那些朋友很少的人来说，从众（即变得更像伴侣）可能是促进兼容性以加强现有友谊的重要策略。