Evidence in support of a model that predicts how biological and environmental factors interact to influence spatial skills.

It was proposed, based on M. Annett (1985), that individuals biologically predisposed to poorer spatial skills are less likely to capitalize on opportunities to develop these skills. Using an analysis of variance design assessing mental rotation skills in 2 cohorts of 8th graders (365 students), the authors found a significant 3-way interaction (Brothers x Family Handedness x Gender). For the girls with brothers, those from all right-handed families had lower mental rotation scores than did the other girls. For the 2nd cohort, among those children who participated in mental-rotation-type activities with their brothers, both boys and girls from all right-handed families performed more poorly on the mental rotation test than did the other children with brothers. Thus, compared with other children, the children from all right-handed families do not appear to be able to use their spatial experiences with male siblings to increase their spatial skills.