Babies born very prematurely or severely underweight have a higher risk of becoming introverted, neurotic and risk averse as adults, research suggests.
Scientists say such a personality profile could help explain the higher rates of career and relationship difficulties experienced by this group in later life.
The study, by the University of Warwick, followed 200 German adults born between 1985 and 1986 either very prematurely or with a birth weight below 1.5kg (3lb 5oz)
A similar number of adults born at full term and at a normal weight also provided the team of researchers with information about their personality traits.
Criteria
These were assessed across five criteria - introversion, neuroticism, levels of openness to new experiences, agreeableness and conscientiousness.
Adults who had been born very prematurely and underweight scored significantly higher on all but two of the personality traits - conscientiousness and openness.
They also reported significantly higher levels of autistic spectrum behaviours, along with lower levels of risk taking.
Researchers say these traits describe a "socially withdrawn" personality, or someone who is easily worried, less socially engaged, less interested in taking risks and less communicative.
"If identified early parents could be provided with techniques to foster their child's social skills to help compensate for socially withdrawn personality characteristics," said Prof Dieter Wolke, who led the study.