This article was authored by Pragya Arya and Danny Rahal as part of the 2018 pre-graduate spotlight week.

Teenagers are notorious for being irresponsible and making bad decisions. Almost all of us have witnessed or bore the brunt of parents nagging kids to take “important” situations more seriously and work harder. TV producers and novelists both love to display the fairly common occurrence of a teenager staying up late partying or texting friends the night before an important test. Is this really how all teenagers behave and if so, why? Recent research has shown that such behavior is more than just the perception of overbearing parents and that there may be a neurological explanation behind it.

Previous research has shown that adults first assess the value or stakes of a situation and then use cognitive resources according to its specific needs1,2. Adults fare better in situations with higher-stakes, as their brains tend to unconsciously spend more effort during them3-6. Think of higher stakes in terms of gambling- if you place a higher bet, you stand to gain more but also lose more. How you perform on a single large gamble can make a huge difference for you, so the stakes are high. Adult brains use more corticostriatal connections6 and prefrontal recruitment1,7,8 in response to such high stakes. These systems are responsible for directing actions based on the context you are in. Greater cortciostriatal connections help connect brain regions responsible for selecting actions to the regions that judge the demands of your environment. In doing so, they help predict the best possible course of action and guide your behavior towards it. Adult brains selectively increase these recruitment patterns only in important situations and not in general day-to-day life. This explains why you may frequently trip up at a routine weekly meeting with your boss but will bring your A-game to a high-stakes job interview.

Do adolescents also demonstrate such adaptability in performance? If not, when in the course of development does this ability come along? Researchers from Harvard University used functional magnetic resonance imaging (fMRI) to study brain activity in teenagers aged 13-20 while they were playing a game9. In the game, participants were shown pictures of planets and had to press a button to indicate whether a planet had craters or stripes on it. They received money for correct responses and lost money for incorrect responses. The researchers altered the stakes of the game by changing the amount of money. In the high-stakes version, the participant could earn $1 if they answered correctly, or lose $0.50 if they answered incorrectly. In the low-stakes condition, they could earn $0.20 for a correct response and lose $0.10 for an incorrect response, so they could gain and lose one-fifth the amount as compared to the high-stakes version. The researchers believed the different earnings and losses between the conditions were representative of the difference between real-life important and less important situations.

The researchers investigated whether adolescents would do better in the higher-stakes conditions, similar to adults. They found that teenagers aged 13-18 did not improve their performance in the high-stakes situations. Performance generally increased with age, as the oldest teenagers did the best at the task, and this difference was most significantly seen for the high-stakes version. The 19- and 20-year-olds were the only ones who performed significantly better during the high-stakes task than during the low-stakes task. So, adolescents perform similarly well at unimportant and important tasks when they are young, but become better at important tasks as they approach adulthood. As they get older, teenagers are able to improve their performance when the stakes demand it.

Teenagers didn’t just have more difficulty with the high-stakes situation, but their brain responded differently to these situations. The participants completed the game in a scanner, so the researchers looked at neural imaging and identified a neurodevelopmental basis for the differences in performance- as adolescents got older, they were better able to recruit specific parts of their prefrontal cortex that improve performance during high stakes situations. fMRI analyses also showed an increase in corticostriatal activity with age. Like in adults, the greater corticostriatal connectivity found in older adolescents was related to a boost in performance on high-stakes tasks. The differences in task performance by age were fully driven by differences in neural connectivity, even after accounting for individuals’ IQ and reaction time.

What if teenagers just can’t tell when a situation is important? Another hypothesis was that teenagers are better able to distinguish between high- and low-stakes situations as they age. However, in this study the adolescents correctly judged the higher-stakes tasks as having higher value than the low-stakes tasks. They had no problem identifying which situations were more important or valuable. The younger teenagers were just constrained by their neurodevelopment and unable to perform better in the higher stakes situations.

Taken together, the results suggest that younger adolescents have difficulty with cognitive control, or allocating resources like attention and mental effort in order to improve their performance on specific tasks. It shows that there is a neurodevelopmental reason for this inability and that adolescents develop it as they reach adulthood. With increasing cognitive maturity, adolescents can use the value of a situation as a motivational basis to improve their performance.

What implications does this hold for teenagers’ daily lives? One applies to education. It may not be that your teen isn’t taking an assignment seriously– he or she may know it’s important but simply has not developed the cognitive skills to excel at more important tasks. If teenagers don’t perform any better in an extremely important situation as compared to a less important one, it may be more beneficial to grade them based on multiple smaller assignments or exams rather than one extremely stressful final exam. It also means that they are capable of learning and becoming better at several varied skills, since they don’t focus their efforts on only one important one. Moreover, adolescence is generally a stressful time for teenagers. If they know something is important but lack the cognitive control to actually rise to the challenge of the situation, it may stress them out even more. Parents should keep this in mind the next time they tell their teenager off for “being irresponsible” or “not taking school seriously” when they struggle with an important assignment or performance.

Pragya Arya is a third-year undergraduate student from New Delhi, India pursuing a double major in psychology and economics. She is especially interested in the fields of decision-making and hopes to study this extensively while working towards a PhD.

References

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9. Insel, C., Kastman, E. K., Glenn, C. R., & Somerville, L. H. (2017). Development of corticostriatal connectivity constrains goal-directed behavior during adolescence. Nature Communications, 8(1). doi:10.1038/s41467-017-01369-8