Social gaze, social avoidance, and repetitive behavior in fragile X males: a controlled study.

Preference for social gaze as well as the percentage occurrence of social gaze, nonverbal social avoidance, and nonverbal repetitive behaviors were examined in autistic and nonautistic prepubertal males with the fragile X syndrome (fra[X]) during social interaction with a parent or stranger. Comparison groups were nonhandicapped, Down syndrome, atypical pervasive developmental disorder, and autistic males. The subjects with fra(X) and the nonhandicapped and Down syndrome control subjects discriminated parent from stranger as evidenced by their avoidance behavior. The overall percentage of avoidance was higher, however, for both parent and stranger, among the males with fra(X). Autistic and atypical groups without fra(X) failed to discriminate parent from stranger in their avoidance behavior. Possible explanations for these group differences in terms of language level or degree of language demand were ruled out. Implications for research concerning the relations among fra(X), autism, and mental retardation were discussed.