Even if you don't give your baby that ubiquitous shape sorter, he or she will perceive different shapes on his or her own, according to a new study.
The study found that despite minimal exposure to the regular geometric objects found in developed countries, African tribal people perceive shapes as well as westerners.
The findings suggest that the brain's ability to understand shapes develops without the influence of immersion in simple, manufactured objects.
"In terms of perceiving the world … either genetics or the natural world will give you the right type of experiences," said lead author Irving Biederman, at the University of Southern California's College of Letters, Arts and Sciences.
The researchers specifically measured subjects' sensitivity to "non-accidental" properties of objects, such as whether they have straight or curved edges.
A theory of shape recognition developed by Biederman holds that the brain is more sensitive to non-accidental properties which stay the same as an object rotates in space ? than to metric properties, such as degree of curvature, that do appear to vary with orientation.
In one experiment, subjects were asked to identify which of two geometric objects was an exact match to a sample object. The one that didn't match differed either in a non-accidental or metric property.
The researchers found that Western college students and members of the semi-nomadic Himba tribe of northwestern Namibia, a rural area bordering Angola, both showed greater sensitivity to non-accidental properties.
The findings indicate that parents can probably toss the beloved shape sorter on the large heap of educational toys toddlers do not really need.
Shape sorters may have other potential benefits such as fine motor training. And some children simply enjoy them. But Biederman questioned the main advertised benefit of the toys.
"Your kids will grow up being able to see shapes just fine without specific training," he said.
"The experiment offers, to our knowledge, the most rigorous assessment of the effects of exposure to modern artifacts on the representation of shape," he added.
The study is published online in Psychological Science.