Results from analyses of sex ratios as a function of IQ are presented for 623 autistic children and 506 nonautistic communication-handicapped and behavior-disordered children. Proportionately more autistic females were found to have IQs of 34 or below than above 34. However, a linear trend of an increasing number of males with increasing…

This study of 199 individuals with autism, 74 with pervasive developmental disorder or autistic-like symptoms (PDD-NOS), and 215 with non-PDD developmental disorders found that the 3 groups differed in the various measures of severity of autism. Sex differences were primarily confined to intelligence quotient and were not prominent in other…

This study of hyperlexia in 80 children with developmental delays found no significant differences in the frequency of hyperlexia in girls compared with boys; a significantly elevated frequency of hyperlexia in children diagnosed with pervasive developmental disorders (PDD) compared with children with non-PDD diagnoses; and a similar range of IQ…

Interviews with parents of 30 school-age girls with fragile X syndrome (fraX) and 31 age- and IQ-matched controls concerning autistic behaviors found that girls with fraX had significantly more autistic behaviors than controls, but incidence of autistic behaviors was not correlated with IQ. Anxiety and posterior cerebellar area measures were also…

Comparison of 384 male and 91 female autistic children (three through eight years old) revealed that females as a group scored less well on intelligence tests. Boys also performed better than girls on eye-hand integration and perceptual tasks. Predictions of female superiority in affect and receptive vocabulary were not supported. (CL)

Interviews with 21 high-functioning adults with autism and 20 mildly to moderately mentally retarded adults without autism indicated that the mentally retarded group had more sexual experiences, with no intergroup differences in sexual knowledge or interest. Intelligence quotient was positively correlated with knowledge scores and males had…

The Autism Diagnostic Interview was used to assess the difference between a group of 21 males and 21 females (ages 6-36) with autism with equivalent chronological nonverbal intelligence quotients greater than 60. Males were rated more severely autistic than females on several measures of early social development but not in other areas such as…

A Canadian study compared the rate of cognitive disabilities in 156 relatives of 49 individuals with autism to that found in 55 relatives of 18 individuals with mental retardation. No differences were found; however, female and low IQ individuals were found to have higher family histories of cognitive disabilities. (Author/CR)

Platelet serotonin (5HT) levels of 5 autistic subjects (ages 16-37) who had siblings with either autism or pervasive developmental disorder were significantly higher than levels of 23 autistic subjects without affected siblings. Autistic subjects without affected siblings had 5HT levels significantly higher than 10 normal controls. Sex, age, and…