Children’s hands ‘give clues to mental agility’

Those with more symmetrical hands are less likely to slow down mentally with age. Picture: Getty

Youngsters with balanced physical proportions were able to react more quickly in a series of mental tests.

Researchers said the study had provided evidence that these two predictors of later health – symmetry and reactions – are related in early life, suggesting a connection from an early age between bodily symmetry and mental performance.

The finding was consistent even after accounting for age and gender differences.

Previous studies have already revealed a link between bodily symmetry and mental performance in old age, as men with more symmetrical faces are less likely to experience a slowdown of brain power in later life.

Health data from 856 children aged four to 15 in Edinburgh was used in the new study.

The children were selected from those attending the Edinburgh International Science Festival after their parents gave consent for them to take part.

Professor Ian Deary, director of the centre for cognitive ageing and cognitive epidemiology at the University of Edinburgh, who led the research project, said there were suggestions in scientific literature that faster responses and greater bodily symmetry were slightly related to better health outcomes.

The study wanted to test whether response speed and hand symmetry were related in children, prior to any effects of chronic adult illnesses.

Researchers from the universities of Edinburgh and Glasgow measured the children’s hand symmetry using a digital scanner and their reaction times were measured in a computer-based test.

Professor Deary said the study could provide clues on how the mind and body develop together over the decades.

“The connection between physical symmetry and reaction times could be an important clue to health and well-being over a person’s life course,” he said. “This finding can shed light on how the mind and the body develop together from childhood to older age.

“We did not think there would be a large association between hand symmetry and speediness of response, but we did find a slight and significant one. It is an interesting small contribution to our trying to understand how early development might link with later health.”

Professor Deary added that bodily symmetry could be a sign of biological fitness.

“There was a slight association such that faster responses went, on average, with greater hand symmetry. We now have evidence that these two predictors of later health are related in early life,” he said.

Previous studies indicate that reaction times are an important indicator of health, and reaction times speed up significantly as children approach adulthood, only to slow down when approaching older age.

Dr David Hope, of the centre for medical education at the University of Edinburgh, said: “This finding links cognitive ability and health very early in the life course – even before school-age physical actions are connected with a person’s body then reflected in mental function.”

The study, which is published in the journal Developmental Psychology, was supported by the University of Edinburgh and the cross-council Lifelong Health and Well-being Initiative.