This study investigated sex differences in estimated general and multiple intelligence in school children, their parents, and their teachers. There were three groups of participants: 285 (149 female, 136 male) pupils of a mixed government-run comprehensive school, between the ages of 13 and 16 years; 93 mothers and 58 fathers of the pupils; and five female and eight male teachers. Children estimated their own and their parents' IQ, whilst the parents estimated their own and their children's IQ; the teachers estimated only the children's intelligence. The aims of this study were firstly to assess whether perceptions of male intellectual superiority were observable in school age children and school teachers, and to make direct comparisons between the children's self-estimations and those of the parents and the teachers. Secondly, this study aimed to replicate previous literature on adult self-estimations of overall and multiple intelligences, and to compare these to estimations by children of these adults (their parents). Fewer sex differences were observed than expected. Teachers' estimations did not follow conceptions of male superiority. The patterns of sex differences in mother and teacher estimations of children were similar to each other, as were those of fathers and children. Verbal and numerical abilities were found to be most closely related to estimations of overall IQ in all three groups. Most striking was the lack of correlation between father and daughter estimations of each other. Reasons why this study failed to replicate findings on adult samples are discussed. Copyright © 2002 John Wiley & Sons, Ltd.