Toddlers temperament provides clues to adult outcomes

Researchers found that infants whose behavior showed inhibition tend to have a reserved, introverted personality at age 26.

Similarly, the research indicated that adolescents who showed sensitivity to making mistakes had a higher risk for disorders like anxiety and depression as adults.

The National Institutes of Health funded the study that provided strong evidence of the impact of temperament in infants on adult outcomes. The study was published in the Proceedings of the National Academy of Sciences.

“While many studies link early childhood behavior to risk for psychopathology, the findings in our study are unique,” Daniel Pine, M.D., a study author and chief of the NIMH Section on Development and Affective Neuroscience, told the National Institutes of Health. “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.”

Temperament is defined as the biological differences in how people respond to the world both behaviorally and emotionally, according to NIH. Infancy temperament is the foundation of personality later in life.

Behavioral inhibition, a specific type of temperament, gets characterized by fearful, avoidant and cautious behavior toward unfamiliar situations, people and objects. The study shows BI as relatively stable across toddlerhood and childhood. A greater risk is shown in children with BI for developing anxiety disorders and social withdrawal thank children without it, according to NIH. 

Only two studies so far have followed inhibited children from early childhood to adulthood. This study was conducted by researchers at the National Institute of Mental Health, the University of Maryland, College Park and the Catholic University of America, Washington, D.C. The study has been following participants since they were 14 months old, according to NIH. 

Researchers also included A neurophysiological measure was also included in the study. It would help researchers identify differences in participants for their later psychopathology.

Participants came back to the lab at age 15 for neurophysiological data. This data was used to assess a negative dip in the electrical signal recorded form the brain. 

This error-related negativity (ERN) occurs after incorrect responses on computerized tasks, the National Institutes of Health said. ERN mirrors the degree to which participants are sensitive to errors. A larger ERN signal was associated with internalizing conditions like anxiety. A smaller ERN gets associated with conditions like substance abuse or impulsivity.

The participants came back again at age 26 to assess their personalities, psychopathology, social functioning, education and employment outcomes.

A BI at 14 months predicted a participant at age 26 to have a more reserved personality. It also predicted increased levels of internalizing psychopathology, but that was shown only in participants who also displayed larger ERN signals at age 15, according to the study.

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