Do adolescents always take more risks than adults? A within-subjects developmental study of context effects on decision making and processing

Abstract

Adolescents take more risks than adults in the real world, but laboratory experiments do not consistently demonstrate this pattern. In the current study, we examine the possibility that age differences in decision making vary as a function of the nature of the task (e.g., how information about risk is learned) and contextual features of choices (e.g., the relative favorability of choice outcomes), due to age differences in psychological constructs and physiological processes related to choice (e.g., weighting of rare probabilities, sensitivity to expected value, sampling, pupil dilation). Adolescents and adults made the same 24 choices between risky and safe options twice: once based on descriptions of each option, and once based on experience gained from sampling the options repeatedly. We systematically varied contextual features of options, facilitating a fine-grained analysis of age differences in response to these features. Eye-tracking and experience-sampling measures allowed tests of age differences in predecisional processes. Results in adolescent and adult participants were similar in several respects, including mean risk-taking rates and eye-gaze patterns. However, adolescents' and adults' choice behavior and process measures varied as a function of decision context. Surprisingly, age differences were most pronounced in description, with only marginal differences in experience. Results suggest that probability weighting, expected-value sensitivity, experience sampling and pupil dilation patterns may change with age. Overall, results are consistent with the notion that adolescents are more prone than adults to take risks when faced with unlikely but costly negative outcomes, and broadly point to complex interactions between multiple psychological constructs that develop across adolescence.

Fig 1. Illustration of rare-weighting biases in relation to choices encountered in the real world.

Fig 2. Task schematic.

(A) Decisions from description layouts displaying two representative options. The layout type (horizontal [left] or vertical [right]) was randomized on every trial. The side of the screen on which the risky and safe options appeared, and the position of the rare and frequent outcomes within the risky grid (top/bottom in horizontal layout, left/right in vertical layout) were also randomized. (B) A representative trial from the decisions from experience format. Participants were presented with unlabeled point machines and sampled from the machines as many times as they wanted. After each sample, an outcome from that machine was drawn based on the underlying probability distribution and shown for 1s. Participants pressed enter to indicate they were ready to make their final decision and then indicated their choice on the final decision screen.

Fig 3. Results from decisions from description regressions.

(A) Main effects in the base model. (B) Significant interaction effect–Rare Favorability X Age Group. (C) Significant interaction effect–Expected Value Difference (Risky-Safe) X Age Group. **p < .01.

Fig 4. Looking time by age group interaction.

In decisions from description, a significant interaction between the proportion of looking time at the risky option and age group to predict the likelihood of choosing the risky option. Adults were more likely than adolescents to choose the option they looked at longer.

Fig 5. Results from description models with pupil dilation data.

Main and interaction effects from description glmer models that included pupil dilation (indexed as proportion change from baseline). (A) Main effects from the base model. (B) Significant interaction effect–Rare Favorability X Age Group X Pupil Dilation; (C) Significant interaction effect–Expected Value Difference (Risky-Safe Option) X Age Group X Pupil Dilation. *p < .05, **p < .01, ***p < .001.

Fig 6. Results from glmer models in decisions from experience.

(A) Main effects in a base model. (B) Marginally significant interaction effect–Rare Favorability X Age Group. (C) Marginally significant interaction effect–Experienced Expected Value Difference (Risky-Safe) X Age Group. **p < .01, ***p < .001.

Fig 7. Graphical depiction of age patterns in rare-outcome weighting.

Adults (top) make choices as if they overweight rare outcomes in description (consistent with Prospect Theory predictions) and underweight rare outcomes in experience. Adolescents appear to underweight rare outcomes in both description and experience, but this underweighting is more pronounced in experience.