People in Western countries are increasingly having children later in life. For women having children at an older age can increase the risk of them having Down's syndrome but a number of studies are now suggesting that older fatherhood could carry risks too. Recent studies have linked older fatherhood to autism and schizophrenia and a study of 33,437 children born between 1959 and 1965 has suggested that it could result in a lower IQ as well. The study - carried out by researchers in Australia but based on data from children in the U.S. - tested the children's sensory discrimination, hand-eye coordination, reading, spelling and arithmetic at 8 months (presumably this was only their sensory discrimination and hand-eye coordination!), four and seven. The study found that the older the father the more likely the child was to have lower scores on the test. There was no link between mother's age and children's IQ. The researchers thought that this might be because while the older women were more likely to be able to provide a supportive environment for their children there could be a decline in the quality of men's sperm as they get older.
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