A four-year-old's people-drawing ability provides an indicator of his or her intelligence at the age of 14, scientists have found.
Parents might laugh at their child's quaint crayon scribbles, but the balloon heads and stick-like limbs have a serious hidden meaning, revealing a connection with gene-driven intelligence that has a measurable effect 10 years later.
Psychologists got 15,504 children aged four to take part in a "draw-a-child" test, rating each picture from zero to 12.
A "moderate" association was seen between higher scores and intelligence test results both at the age of four and 14.
Lead scientist Dr Rosalind Arden, of the Institute of Psychiatry, King's College London, said: "The draw-a-child test was devised in the 1920s to assess children's intelligence, so the fact the test correlated with intelligence at age four was expected. What surprised us was that it correlated with intelligence a decade later.
"It does not mean that parents should worry if their child draws badly. Drawing ability does not determine intelligence - there are countless factors, both genetic and environmental, which affect intelligence in later life."
Drawings were judged on the presence and correct quantity of features such as the head, eyes, nose, mouth, ears, hair, body and arms, and a point was awarded for each correctly presented feature.