Adults who were born premature are more likely to refrain from social activities and display signs of autism, according to a recent study.

Researchers at the University of Warwick found that adults born very preterm scored highly for displaying a socially withdrawn personality, indicated by autistic features, neuroticism, introversion and decreased risk taking.

"Personality characteristics are very important because they help people to develop into adult roles and form and maintain social relationships," Professor Dieter Wolke, who led the study, said in a statement. "Very premature and very low birth weight adults who have a socially withdrawn personality might experience difficulty dealing with social relationships with their peers, friends and partners."

For the study, researchers collected and analyzed data from 200 adults born either very premature (before 32 weeks) or with very low birth weight between the years 1985 and 1986. They also had a similar number of term born adults provide information about personality features.

Their analysis suggests that being born with a very low birth weight or very pre-term carries a greater risk of developing a withdrawn personality as an adult. Wolke attributes brain development related to premature birth for very pre-term or very low birth weight adults scoring higher for a socially withdrawn personality.

Earlier studies have linked poor peer relations and social-emotional problems in childhood with regional disruptions in the white matter, in the right orbital frontal cortex which is a region involved in social regulations and social cognition. Early stresses experienced in the womb and having over-protective parents are also thought to be a possible factor in effecting a withdrawn personality.

"Defining a general personality profile is important because this higher order personality factor may help to partly explain the social difficulties these individuals experience in adult roles, such as in peer and partner relationships and career" Wolke added.

The findings are detailed in the journal Archives of Disease in Childhood: Fetal & Neonatal Edition.