A Cambridge University study identified six potential factors in a child's history which are associated with persistent offending: regarded as a troublemaker by teacher; impoverished family background; parents using harsh and erratic discipline; low intelligence; low academic attainment by the age of 10; and being regarded as "daring" at the age of 8. A recent survey by a children's charity in the UK showed that more than 90 percent of young offenders were bullies at school.