Study shows early sex differences in spatial-learning skills

University researchers have demonstrated for the first time that boys have an advantage over girls in their understanding of spatial relationships by age 4 1/2, much earlier than previously thought.

Spatial skills, which help people interpret maps and technical drawings, are important to everyday living as well as performing well in school and on the job. Scholars have known for some time that males outperform females in this area by the time they reach adolescence.

Although other work has hinted at the possibility of early sex differences in spatial understanding, the recently published article “Early Sex Differences in Spatial Skill” reports the first unambiguous evidence that these sex differences develop during the preschool years.

“These findings should put to rest claims that adolescence marks the onset of sex differences in spatial skills,” said Susan Levine, Professor in Psychology and the lead author of the article published in the current issue of Developmental Psychology. Her co-authors are Janellen Huttenlocher, the William S. Gray Professor in Psychology; Amy Taylor, a recent A.B. graduate; and Adela Langrock, a Ph.D. student at the University.

Other studies suggest that the gap between boys and girls in spatial skill may widen as they grow older, possibly due to greater spatial input to males. “Recent changes in the work place make increasing demands on the use of spatial skills and could accordingly disadvantage women,” said Huttenlocher.

“Greater demands on spatial skill are made by various technical tasks that are pervasive in a complex society, such as interpretation of graphs, maps, architectural drawings and X-rays,” Huttenlocher said. The tasks often require an ability to mentally rotate images, she added.

Mental rotation is a specific example of spatial transformation. Spatial transformation is the general change in an individual’s view of the relationship between him or herself and an object or array of objects. Mental rotation is a particular process through which a viewer predicts what any array of objects would look like if it were rotated on its axis by some number of degrees.

For their investigation, the University researchers studied 288 children, using mental-rotation tests. They divided the children, who were aged 4 years to 6 years, 11 months, into six age groups of 24 boys and 24 girls. Levine and her colleagues used mental-rotation tasks because mental rotation is the spatial skill that other studies have shown to be the strongest determinant of differences in spatial skill between males and females.

Researchers presented the children with pictures of two pieces of a complex geometric shape. They then asked the children to show which one of four shapes could be created by the two pictured pieces. To do this, the children had to mentally rotate the two pieces.

The University researchers found that boys began to outperform girls at 4 years of age.

However, the origins of the differences in spatial skills between boys and girls are unclear. “They could be related to the way they are reared, caused by biological factors or both,” Levine said. Boys tend to play in a way that encourages spatial-skill development. They play with blocks and build models, for example. But researchers do not know if they develop spatial skills through these influences, or if their brains have evolved to process spatial information differently, perhaps in a way related to the division of labor between men and women in hunter/gatherer societies.

“We think quite a bit can be done to enrich the learning environment so that girls develop high levels of spatial skills,” Levine explained. “Parents and teachers need to recognize the differences, however, and realize that if a girl is having trouble working on a task that requires spatial thinking, she may need extra encouragement and help.”

Huttenlocher and Levine are members of the Early Childhood Initiative at the University, an innovative program to study early childhood development. It is funded through a grant from the Robert R. McCormick Tribune Foundation.