2We demonstrate that book-carrying behavior in grade school, junior high, high school, and college is sexually dimorphic. A book-carrying category system containing eight categories was employed to record the book-carrying styles of about 60 males and 60 females in each of 10 grade groups from kindergarten through college. Males and females employed similar carrying styles in kindergarten but differed significantly thereafter. The variety of styles employed diminished with age and sexual stereotypy increased. Males adopted adult-like carrying behavior at an earlier age than females, whose carrying styles showed little change between kindergarten and sixth grade, followed by a drastic change in junior high. Male-female differences in physical size, shape, and strength were considered in attempting to account for the sexually dimorphic carrying behavior. These variables, as well as others, are probably important in the development of book-carrying behavior but don’t adequately account for the early appearance of sex differences. © 1976, The Psychonomic Society, Inc.. All rights reserved.
