Every parent knows that young teenagers start ignoring most of what we say. It’s part of normal child development, and child psychologists explain it as part of a teenager’s growing need for independence. According to a 2016 neurological study (only recently published), the shift may be due to biology as well as psychology.
The study included 46 kids, ages 7 to 16, who underwent MRI scans, allowing researchers to track brain activity while the children listened to recordings of either their mother’s voices or unfamiliar female voices. The younger kids’ brains reacted more strongly to their mother’s voices. The reward center of the 13-16-year-old teens’ brains, however, lit up more often in response to the unfamiliar voice. The study also found that those teens’ brain areas involved in creating social memories also became more active the older the teenager was.
This is only one study, and it included a small sample size, but it does fit with what we already know about teen psychosocial development. One of the researchers noted that the study is “in line with evidence of broader shifts in the teenage brain's reward system, where it becomes more responsive to things like novelty and risk-taking.”
The study was limited to children with no history of neurological or other difficulties and who had lived with their mothers since birth. We can’t generalize the findings to children with neurodivergent conditions, such as autism, or who have suffered family disruption. The study does raise the possibility, however, that teenagers may not be willfully ignoring us. Rather, their brains just no longer notice what we say.