"Look at me when I'm speaking to you," may not be the brightest command if teachers want an answer.
In fact, doing the opposite may spark a better answer. The more difficult the question, the more likely it is that primary-aged children will look away for a few seconds while considering a response.
Research in Stirling, Clackmannanshire and Glasgow primaries, carried out by Gwyneth Doherty-Sneddon at Stirling University, shows that older children look away more when they are trying hard to concentrate. It is a skill that develops with age.
Younger children tend to look more at the teacher when faced with a question. "This suggests a higher reliance on visual clues at lower ages and perhaps an attempt to elicit help from the adult rather than work things out for themselves," she says.
Dr Doherty-Sneddon, writing in the latest edition of the Psychologist magazine, says: "There is a tendency in many cultures to encourage children to 'look at me when I'm speaking to you', and to interpret looking away as a sign of disengagement or lack of interest.
"What our research clearly showed was that primary school-aged children used gaze aversion to help them concentrate on difficult material.
Therefore, provided the aversion is appropriately timed within the interaction (especially during thinking, and to a lesser extent during speaking), it is something to be encouraged rather than discouraged."
Dr Doherty-Sneddon maintains that looking away in class when asked a question is a sign that pupils are on task.
Results from a forthcoming study may show whether children turn their eyes away for social or cognitive reasons. Dr Doherty-Sneddon asks: "In other words, does looking away help because children feel embarrassed or self-conscious when they find questions difficult?
"Or does gaze aversion work because it reduces the amount of complex visual information the children are processing when they look away? Perhaps both explanations play a part."
Evidence already shows that children turn away more when they are about to understand something compared with when they fully understand it and when they do not understand it at all.
"We are only just beginning to understand the link between children's patterns of eye gaze and their cognition," Dr Doherty-Sneddon admits.