LaPsyDÉ

Co-supervised by Mathieu Cassotti & Sylvain Moutier

Abstract :

In order to account for the characteristics of risk-taking specific to adolescence, new neurocognitive models
presuppose a competition between two systems with distinct developmental trajectories: an emotional system and a top- down control system. Indeed, heightened risk-taking in adolescence could result from increased emotional sensitivity in socio-emotional contexts, including the presence of peers, combined with immature control processes underlying emotional regulation. Unfortunately, these models ignore the potential impact of varying levels of uncertainty in risky situations, despite advances in developmental psychology that suggest adolescent’s capacities differ between risky decision-making and decision-making under ambiguity. Although adolescents are fully competent at evaluating probabilities and entertaining outcome likelihoods, they fail to make advantageous choices when such information is not directly available but must be inferred from their own experience. Thus, the overall aim of this thesis is to examine the impact of both the information level regarding risks and of the social-emotional context on risk-taking during adolescence.
After showing in a first study that adults are largely ambiguity-averse in situations in which information is missing, we investigated the exact developmental trajectory of such ambiguity aversion in children, adolescents and adults. This second study characterizes ambiguity aversion as an affective strategy that gradually develops at the beginning of adolescence, while demonstrating that adolescents display an ambiguity aversion as much as adults. Then, study 3 aimed to clarify the influence of information level on adolescents’ risk-taking behaviors by directly comparing informed and uninformed situations. Results showed that adolescents exhibit a suboptimal ability to adjust risk-taking to the risk level in the non-informed condition, but are efficient in making advantageous choices when explicit information is provided. Taken together, the first three studies suggest that heightened risk-taking in adolescence does not result from an increased ambiguity tolerance but rather from a specific impairment of feedback-based learning. Given adolescents’ learning impairments in ambiguous situations, study 4 aimed to specify the impact of cautious or risky social influence on risk- taking behaviors, depending on the level of uncertainty. This final study underlies the potential positive influence of peers on risky behaviors. Peers’ experiences could play a particular role by providing social information that is likely to balance the difficulties adolescents have learning from their own experience.

Keywords: Adolescence, Risk-taking, Risky decision-making, Decision-making under ambiguity, Uncertainty level, Ambiguity aversion, Social information, Peers influence.