Have you ever wondered why your little kid paints trees blue or grass red? Well, a researcher from University of Wisconsin has got the answer for the query.
It is so because kids can't "bind" together the colour and shape of an object, Vanessa Simmering claims.
Since the brain stores colour and shape in different groups of neurons, Simmering suspects that young children have not yet developed the ability to link the information stored in each, reports New Scientist.
In order to verify her hypothesis, the expert asked 28 four-year-olds and 28 five-year-olds to view images of up to three shapes on a computer screen for a short time.
Soon after, the children were shown a new image, and asked whether it was the same as the previous image or had subtly changed.
The study found that although the four-year-olds could find out when a new colour had been introduced, they did not seem to notice if two of the shapes had just swapped their original colours, performing no better than chance on those trials.
The five-year-olds had no such problem, suggesting that the ability to combine the different types of visual information develops after the child's fifth year, the study claimed.
The research will be presented at the annual meeting of the Cognitive Science Society in Amsterdam at the end of July.