It has been assumed that adolescents increase risk-taking tendencies when peers are present but findings on experimental decision-making have been inconclusive. Most studies focus on risk-taking tendencies, ignoring the effects peer presence can exert over other cognitive processes involved in decision-making, as well as any other underlying developmental and individual differences. In the present study, the trial-by-trial choice behavior was analyzed in a task in which adolescents adjust to dynamically changing risk probabilities. Using Bayesian modeling, the study aimed to infer about peer presence effects on risk-taking tendencies but also on reactions to, exploration of, and learning from positive and negative outcomes of risk-taking. 184 pre- to late adolescents (M = 14.09 years, min = 8.59, max = 18.97, SD = 2.95, 47% female) conducted the Balloon Analog Risk Task under two conditions: Once alone and once in the presence of a (non-existent) peer observing them virtually. Findings revealed that (a) peer observation reduced risk-taking but increased exploration tendencies and (b) that individual differences modulated this effect. Especially female pre-adolescents increased their openness to explore different choice outcomes when a peer observed their behavior. These results support the assumption that the occurrence and direction of peer influences on risk-taking depend on a person-environment interaction, emphasizing the dynamic role peers play in adolescent risk-taking.

据推测，当有同龄人在场时，青少年会增加冒险倾向，但关于实验性决策的研究结果尚无定论。大多数研究都关注冒险倾向，忽略了同伴的存在对决策中涉及的其他认知过程以及任何其他潜在的发展和个体差异的影响。在本研究中，在青少年适应动态变化的风险概率的任务中分析了逐次试验的选择行为。该研究使用贝叶斯模型，旨在推断同伴存在对冒险倾向的影响，以及对冒险的积极和消极结果的反应、探索和学习的影响。184 名青少年（M = 14.09 岁，最小值 = 8.59，最大值 = 18.97，SD = 2.95, 47% 女性）在两种情况下进行气球模拟风险任务：一次是单独的，一次是在（不存在的）同行虚拟观察他们的情况下。研究结果表明，（a）同行观察减少了冒险，但增加了探索倾向；（b）个体差异调节了这种影响。当同伴观察她们的行为时，尤其是女性青春期前的女性更愿意探索不同的选择结果。这些结果支持了同伴对冒险的影响的发生和方向取决于人与环境的相互作用的假设，强调了同伴在青少年冒险中所起的动态作用。