A study of 330 girls by researchers at the University of Alabama, Birmingham, looked into the links between early maturation, parenting and delinquent and aggressive behaviour. A quarter of the girls had matured early, defined as starting their periods a year before the average age for females of their racial and ethnic group. Girls who had matured earlier were more likely to be delinquent than other girls but no more likely to be aggressive, unless they also experienced low levels of parental nurturance, communication and knowledge (of what they were doing and who they were friends with). Early maturing girls could be at more risk of delinquency because they are more likely to be accepted by, and form relationships with, older boys who are more likely than younger children to engage in undesirable behaviour.
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