Parents may wish to pay attention: how your child draws at age four may determine your child's intelligence at age 14, at least according to a new study.

The study, published by researchers at the Institute of Psychiatry at King's College London, shows a direct correlation between how a child draws and intelligence. They also discovered a genetic link between intelligence and drawing.

The study involved over 15,000 children who were part of either identical or non-identical twin sets. At the age of four, parents asked their children to take part in a "Draw-a-Child" test, asking them to draw a picture of a child.

Researchers looked over the test and scored each drawing between 0 and 12, depending on how accurate the drawings were. For example, researchers looked for the proper number of limbs plus a body and a head, along with whether the children drew facial features, such as nose, eyes and mouth. They also gave the children a series of IQ tests, discovering that children who received higher scores on their drawings also rated higher in intelligence.

The researchers followed up with the children 10 years later by giving them another IQ test. They discovered that children who got higher scores on their earlier drawings also scored higher on intelligence tests at age 14.

More importantly, though, researchers found that identical twins scored similarly in both drawing and intelligence at both ages, where non-identical twins did not. This suggests that the link between drawing and intelligence is genetic because identical twins share all their genes.

However, researchers were quick to point out that these results aren't conclusive and that other factors come into play as a child grows in intelligence, such as their upbringing and family environment.

"This does not mean that there is a drawing gene - a child's ability to draw stems from many other abilities, such as observing, holding a pencil, etc.," says Dr. Rosalind Arden, lead author of the study. "We are a long way off understanding how genes influence all these different types of behaviour."

So why did researchers choose drawing for the test? The original Draw-a-child test originates from the 1920s: even then, scientists used it for estimating intelligence in children. Drawing is also one of the most primitive of human behaviors: even the less intelligent cavemen drew.

"Through drawing, we are attempting to show someone else what's in our mind, says Arden. "This capacity to reproduce figures is a uniquely human ability and a sign of cognitive ability, in a similar way to writing, which transformed the human species' ability to store information, and build a civilization."