A new paper links adults born very premature with being socially withdrawn and displaying signs of autism. The work was led by Professor Dieter Wolke at the department of psychology and Warwick Medical School, University of Warwick. He and coauthors correlate adults born very preterm scored highly for displaying a socially withdrawn personality, indicated by autistic features, neuroticism, introversion and decreased risk taking.

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 Very premature and very low birth weight adults who have a socially withdrawn personality might experience difficulty dealing with social relationships with their peers, friends and partners."

The research Personality of adults who were born very preterm has been published in the Archives of Disease in Childhood: Fetal & Neonatal Edition published by BMJ.

The study was conducted in southern Bavaria, Germany. The study had followed children from birth into adulthood when 200 adults born between 1985-86 either very premature (before 32 weeks) or with very low birth weight (less than 1.5kgs) and a similar number of term born adults provided information about personality features.

Their results were not sex-specific, related to income or education, and were compared to a control group of adults who were born healthy in the same obstetric wards. The findings indicate that being born with a very low birth weight or very pre-term carries a greater risk of developing a withdrawn personality as an adult.

This study differs from previous ones which are contradictory; some reported higher introversion or higher neuroticism while others found increased levels of conscientiousness and agreeableness.

In the paper Prof. 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development related to premature birth for very pre-term or very low birth weight adults scoring higher for a socially withdrawn personality. Previous 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experienced in the womb and having over-protective parents are also thought to be a possible factor in effecting a withdrawn personality.

Prof. Wolke said: "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.

"Previous studies have found they are more likely to be bullied at school and less likely to progress to university or attain well paid employment. They are also less likely to form social contacts, to maintain romantic relationships and to have children. If identified early parents could be provided with techniques to foster their child's social skills to help compensate for socially withdrawn personality characteristics."