If you do this as a toddler, you will have this mental health issue as an adult

The more things change the more they stay the same. We’ve all changed quite a bit since our days spent in diapers and cribs, but a new study finds that you may just have a whole lot more in common with your former self than you assume. 

Researchers from the University of Maryland, The Catholic University of America, and the National Institute of Mental Health have uncovered considerable evidence that a baby’s behavioral tendencies and temperament can accurately predict that individual’s personality over 20 years later.

Shy, inhibited, or reserved babies often grow up to be introverted young adults. Moreover, toddlers and adolescents who are especially self-conscious or sensitive about making mistakes are at a higher risk of developing mental health issues like anxiety and depression as an adult.

“While many studies link early childhood behavior to risk for psychopathology, the findings in our study are unique,” says Daniel Pine, M.D., a study author and chief of the NIMH Section on Development and Affective Neuroscience, in a press release. “This is because our study assessed temperament very early in life, linking it with outcomes occurring more than 20 years later through individual differences in neural processes.”

So, how exactly do the study’s authors define temperament? In their words, temperament encompasses “biologically based individual differences in the way people emotionally and behaviorally respond to the world.” Basically, how we react to the occurrences and events in our lives. The research team believes that an infant’s initial temperament serves as a foundation of sorts for that individual’s future personality in adulthood.

One specific aspect of temperament, behavioral inhibition (BI), was primarily focused on. BI usually manifests itself as shy, avoidant, and even fearful behavior around unfamiliar or foreign people, situations, or objects. Prior research had already established that toddlers exhibiting high levels of BI frequently carry those traits into adolescence, and children with BI are also at a greater risk of dealing with anxiety disorders and social isolation in comparison to kids without BI.

Despite lots of research pointing to baby temperament predicting adolescent behavior, there haven’t been many long-term investigations on if these tendencies continue into one’s 20s and beyond. With these questions in mind, the research team gathered a group of babies and measured their BI levels at 14 months old. Then, well over a decade later, the now 15-years-old participants returned for further neurophysiological testing.

This time around, the teenagers were asked to complete a series of tasks while their brain activity was monitored. In people with high BI, the brain experiences a negative dip in electrical activity immediately following an error or mistake. This phenomenon is referred to as error-related negativity (ERN). Researchers used these ERN readings to determine how sensitive and inhibited each teenager was in comparison to their earlier self. Generally, higher ERN levels are associated with a greater risk of mental health issues, while low ERN levels have been linked to impulsivity and substance abuse.

Finally, another 11 years later, participants returned once again at the age of 26 for another round of testing, as well as further questions on their personal life and career outcomes.

“It is amazing that we have been able to keep in touch with this group of people over so many years. First their parents, and now they, continue to be interested and involved in the work,” says study author Nathan Fox, Ph.D., of the University of Maryland’s Department of Human Development and Quantitative Methodology.

With all of that data in hand, the study’s authors were able to come to some pretty groundbreaking determinations. They found that BI at 14 months old predicted a 26-year-old adult with a reserved personality, few romantic relationships, and “lower social functioning” in regards to friends and family. BI in a 14-month-old also predicted a higher risk of depression and anxiety later in life, but that only held true for participants who displayed high levels of ERN at 15-years-old.

BI, however, didn’t predict participants’ education or employment achievements or outcomes.

Amid the ongoing debate of nature versus nurture, these findings certainly indicate that we’re all born with at least a few ingrained traits. It seems some of us are naturally inclined to mentally beat ourselves up after a mistake or feel more self-conscious in public settings. But, just because a child is shy doesn’t mean they’re doomed to a life of loneliness and depression; everyone is capable of taking control of their life and overcoming these predispositions.

“We have studied the biology of behavioral inhibition over time and it is clear that it has a profound effect influencing developmental outcome,” Dr. Fox concludes.

The full study can be found here, published in Proceedings of National Academy of Sciences.

John Anderer is a frequent contributor to Ladders News.