Question

What happens to teen brains that make it difficult for someone like Gary to weigh risk and reward

Answer 1

Since I have no specific I would give the answer generally why teens take risk.

During the adolescence period, people are more susceptible to peer influence and their interest in peer relationship increases. As a result teens are more sensitive towards peer relationship and tend to focus and go with peer decision making than adult. Another reason behind it can be stress as teens are more stressed out when left by peers than adults. Hence social exclusion bothers them more, which results in risk taking behavior. During adolescence, it is observed that teen do risky things like driving fast, when their friends are with them to observe as compared to when they are alone. This also gives us insight why teens do such things, during this phase people try out new things that sticks with them throughout life, it is a period of trial and error to see and test your limits. This motivates and encourages teens to do risky stuff.