Parents' perceptions and preferences concerning sex differences in emotionality in children were investigated by means of a questionnaire which separated attitudes about intensity from attitudes about frequency of emotional expression. The attitudes of 24 working-class parents (4 males and 20 females) whose children attended day care were compared to the attitudes of 23 middle-class parents (1 male and 22 females) whose children were enrolled in preschool programs. The parents were asked four questions about each of four emotions (anger, fear, happiness, and sadness), with a separate rating scale for boys and girls. Results indicated the following significant differences between the two groups of parents: (1) only day care parents perceived a sex difference in frequency of emotional expression, perceiving boys as showing anger more often than girls and girls as showing fear more often than boys; (2) only day care parents reported that they desired sex differences in frequency of emotional expression, desiring boys to show anger more often than girls and girls to show fear more often than boys; (3) only day care parents perceived sex differences in the intensity of emotional expression, perceiving boys as showing anger more intensely than girls and girls as showing sadness and fear more intensely than boys; (4) only day care parents reported desiring sex differences in intensity, desiring boys to show anger more intensely than girls and girls to show fear more intensely than boys. No differences were found between attitudes about frequency and attitudes about intensity of emotional expression. (Author/SS)