Several investigations have reported high frequencies of reading and writin
g disabilities in criminal populations. The aims of the present study were
to assess the frequency of dyslexia among Swedish prison inmates and to rel
ate dyslexia to other indices of neuropsychological functions. Sixty-three
prison inmates with Swedish as their native language, age 19 to 57 years, w
ere examined by interviews, tests of academic achievement, and neuropsychol
ogical assessment. Twenty-six (41%) were diagnosed as dyslexic. As expected
,the dyslexic group performed more poorly on verbal tests as compared to th
e normal readers among the prison inmates, but they also performed more poo
rly on tests measuring nonverbal abilities. The dyslexic group had higher f
requencies of paranoid and avoidant personality disorders compared to the n
ondyslexics. They also reported higher levels of anxiety and suspicion and
a lower degree of socialization. Previous studies report low IQ to be assoc
iated with criminal propensity, supporting the interpretation that a double
handicap (dyslexia and low IQ) increases the risk of entering a criminal c
areer and remaining in it.