If you thought that being accommodating with your teen would get them to cooperate at home, think again. A new study finally explains why taking a step towards it always backfires.
Teenagers have always had a bad rap. When you become a parent, this is a warning that you cannot avoid: “Good luck when he’s a teenager!“It’s the famous “crisis” which generally occurs between the ages of 12 and 18, and which seems to never end for other members of the family who suffer from the character of young people going through puberty. The clichés are stubborn: teenagers lack respect for their elders, they do as they please, they are constantly on their phone, are always lazy… and above all, they only think about themselves.
Of course, some will be the exception that proves the rule, but this is precisely where parents can reassure themselves: there is indeed a rule which says that adolescents are selfish, and that it is completely normal. This is not only in the order of things, but it is a universal behavior that they choose unconsciously, and which has nothing to do with the education they received. In any case, this is what a study from Peking University, published in early 2026 in the scientific journal eLife.
Researchers in cognitive and learning neuroscience conducted the “prisoner’s dilemma” experiment, with 127 adolescents and 134 adults, to compare the choices of young people and their elders. In each turn, the game consists of choosing between cooperating with one’s partner, in which case both benefit, or betraying one’s partner to maximize one’s personal gain. Over more than 100 rounds, the observation is the same: teenagers are systematically less cooperative than adults, even though they are just as capable of recognizing when someone is making an effort for them. That is to say, they voluntarily decide to be selfish. Worse still, not only do teenagers tend to go it alone, but above all, they do it even more when the other person had first chosen to cooperate.
This behavior defies all logic: when an adult sees their partner cooperate several times in a row, their brain adapts and finds satisfaction in returning the favor. But the adolescent does not place any value on this principle of reciprocity, or at least very little. The study confirms that when the teenager is certain that his partner will be nice, turning his back becomes the optimal strategy to maximize his personal gain, to the detriment of the social cohesion that they could have created together in the long term. Simply put, the more you cooperate with a teenager, the less he will cooperate with you. But researchers reassure: this is a normal developmental stage, and not an anomaly. This behavior therefore has nothing to do with poor education or a lack of empathy. At this time of life, the brain is biologically programmed to prioritize self-interest and test boundaries.
So, when an adult reaches out to his teenager and the latter “takes advantage”, it is not a personal aggression nor a parental failure: it is simply the teenager’s brain which applies a strategy, because he knows that he is on conquered and secure ground. Don’t worry, this tendency to take advantage of your kindness will fade over the years. Comparison with the adult group proves that as we mature, brain mechanisms naturally evolve towards reciprocity and a sense of fairness.


