13:58 12 August 2009
Men with symmetrical faces are less likely to lose their memory, intelligence and mental wellbeing in later life, according to new research.
Psychologists at the University of Edinburgh unearthed a link between facial symmetry and mental performance between the ages of 79 and 83.
The researchers analysed results of the 1932 Scottish Mental Survey and mapped the faces of subjects from photographs, to a show a link between physical condition and mental decline.
Researchers proposed that facial symmetry may be indicative of a man who has experienced fewer genetic and environmental disturbances such as diseases, toxins, malnutrition or genetic mutations during his development.
Dr Lars Penke, the leader of the study, said: "Previous research has suggested that cognitive decline is an aspect of body-wide ageing.
"This link could show that facial symmetry can be used as a marker which could predict this decline."
However, the team was unable to find comparable results in women.
Exact reasons for this variance are unknown, but one explanation suggested by the researchers was that DNA has a different effect on ageing among women.
An alternative theory was that mental decline is delayed in women because they tend to live longer.
Dr Penke said: "Mental decline accelerates in old ages especially in the four years before death. We found a link between facial symmetry and this decline, but only in men and no link with the overall cognitive decline we see during a lifetime.
"Statistically, it's strongly significant with facial symmetry explaining about 10% of the cognitive differences for that age group. And although we haven't found the single factor that explains cognitive decline in old age, it's one of the better predictors of it"
Previous research has already shown associations between facial symmetry and general health and perceived physical attractiveness.
The results of the study have been published in the journal Evolution and Human Behaviour.