Can you predict what someone's personality will be like based on their infant behavior? A new study funded by the National Institutes of Health suggests that at least in some ways, you can.
The study isn't the first to look at possible links between babies and their older selves, said study author Dr. Daniel Pine, but it is unique. “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 a term for the biologically-based individual differences in how people respond to the world, both emotionally and in their behavior. One type of temperament the study looked at is called behavioral inhibition, or BI. What does BI look like? Cautious, scared, and avoidant behavior towards the unfamiliar, be it people, items, or places. This trait is relatively stable from infancy through adulthood, and children with BI are more likely to develop social withdrawal and anxiety disorders.
The study is a collaboration of researchers from the University of Maryland, College Park, the Catholic University of America, Washington, D.C., and the National Institute of Mental Health. Together, they recruited participants at four months old, characterized their BI levels at 14 months, and then had the participants return to the lab at age 15 for further study.
Specifically, researchers looked at their Error-Related Negativity, or ERN, which is a measure of how sensitive a person is toward their own errors. (The larger the ERN, the more a participant is likely to develop internalizing conditions, like anxiety, while a smaller ERN is associated with externalizing conditions, such as substance abuse or impulsivity.) Then at 26, participants returned once again for an assessment of their psychopathology, personality, social functioning, and education and employment outcomes.
Presence of BI at 14 months was found to predict, at 26, a more reserved personality, fewer romantic relationships, and lower social functioning with friends and family. BI at 14 months was also found to be a predictor of internalizing conditions, but only if the participant also displayed ERN at 15. There was no apparent link between BI and education or employment outcomes.
“We have studied the biology of behavioral inhibition over time and it is clear that it has a profound effect influencing developmental outcome,” said Dr. Fox. Still, further studies with larger and more diverse sample sizes are needed before we can fully understand the findings.