According to a new study, teens focus on rewards and have a hard time learning to avoid punishment or consider the consequences of alternative actions.
University College London researchers compared how teens and adults learn to make choices based on the available information. They tracked the way in which 18 volunteers aged 12-17 and 20 volunteers aged 18-32 completed tasks in which they had to choose between abstract symbols.
Each symbol was consistently associated with a fixed chance of a reward, punishment, or no outcome. As the trial progressed, participants learned which symbols were likely to lead to each outcome and adjusted their choices accordingly. Teens and adults were equally good at learning to choose symbols associated with reward, but teens were less good at avoiding symbols associated with punishment. Adults also performed significantly better when they were told what would have happened if they had chosen the other symbol after each choice, while teens did not appear to take this information into account.
"From this experimental lab study we can draw conclusions about learning during the teen years. We find that teens and adults learn in different ways, something that might be relevant to education," said lead author Dr. Stefano Palminteri. " Unlike adults, teens are not so good at learning to adjust their choices to avoid punishment. This suggests that incentive systems based on reward rather than punishment may be more effective for this age group. Additionally, we found that teens did not learn from being shown what would have happened if they made alternative choices."
To interpret the results, the researchers developed computational models of learning and ran simulations (模拟)applying them to the results of the study. The first was a simple model, one that learned from rewards, and the second model added to this by also learning from the option that was not chosen. The third model was the most complete and took the full context into account, with equal weight given to punishment avoidance and reward seeking. For example, obtaining no outcome rather than losing a point is weighted equally to gaining a point rather than having no outcome.
Comparing the experimental data to the models, the team found that teens" behavior followed the simple reward-based model while adults" behavior matched the complete, contextual model. "Our study suggests that teens are more receptive to rewards than they are to punishments of equal value," said senior author Dr. Sarah-Jayne Blakemore. "As a result, it may be useful for parents and teachers to frame things in more positive terms."
