A study of 700 children (ages 5-12) investigated whether children's conceptions of and expectations of friendship are determined by chronological age or by mental age. Results found children of differing intellectual abilities pass through the five conception stages of friendship at different ages and at different rates. (Contains 4 references.)…

Evaluates fourth-to seventh-grade children on two aspects of social cognition: interpersonal understanding and means-ends problem-solving ability. Relates the two variables to sex, age, IQ, social class, and multiple dimensions of competence. Both variables significantly correlated with I.Q. while interpersonal understanding also correlated with…

This final report reviews the second phase of a life-span study of boys with fragile X syndrome (FSX), the most common known inherited cause of mental retardation. Males with the syndrome are more severely affected than females and in males, delays are usually evident in all the developmental domains, although cognitive and communication skills…