Consider the Source: Adolescents and Adults Similarly Follow Older Adult Advice More than Peer Advice

<div><p>Individuals learn which of their actions are likely to be rewarded through trial and error. This form of learning is critical for adapting to new situations, which adolescents frequently encounter. Adolescents are also greatly influenced by their peers. The current study tested the extent to which adolescents rely on peer advice to guide their actions. Adolescent and young adult participants completed a probabilistic learning task in which they chose between four pairs of stimuli with different reinforcement probabilities, with one stimulus in each pair more frequently rewarded. Participants received advice about two of these pairs, once from a similarly aged peer and once from an older adult. Crucially, this advice was inaccurate, enabling the dissociation between experience-based and instruction-based learning. Adolescents and adults learned equally well from experience and no age group difference was evident in the overall influence of advice on choices. Surprisingly, when considering the source of advice, there was no evident influence of peer advice on adolescent choices. However, both adolescents and adults were biased toward choosing the stimulus recommended by the older adult. Contrary to conventional wisdom, these data suggest that adolescents may prioritize the advice of older adults over that of peers in certain decision-making contexts.</p></div

Learning phase performance.

<p>Choice performance was measured as the percentage of trials in which participants selected the most frequently rewarded stimulus of each pair (% optimal choice), presented in 10-trial blocks. Both adolescents (black) and adults (white) progressively learned the estimated value of the stimuli; by the end of the learning phase, they were significantly better than chance at choosing the optimal stimuli. Error bars represent SEM.</p

Test phase instruction biases.

<p>Older adult advice biased both adolescents and adults, while neither group were biased by peer advice. Error bars represent SEM.</p

Peer and older adult instruction biases.

<p>Instruction bias scores were calculated by comparing performance on equally valued but differentially instructed pairs, averaging an easier (80% versus 30%) and harder (30% versus 20%) comparison. Peer and older adult instruction bias scores quantified the extent to which either source of advice biased participants’ baseline tendency to choose the higher valued option.</p

Test phase advice preference.

<p>For equally rewarded stimuli (D, F and H had a 30% reward probability), both age groups show a preference for the adult recommended (H), but not the peer recommended (F) stimulus, when compared to the uninstructed (D) stimulus. Error bars represent SEM.</p