It is true that the weights of the brains of male and female newborn babies differ. The female brain is not only significantly lighter at birth than that of the male, but it remains so through all age groups.1 This variance can be explained by the more or less same average difference in body weight and height.2 The brain grows very rapidly during a baby's first few months of life. It has more than doubled in weight by the end of its first year of life and has already reached about seventy-five per cent of the final weight of an adult brain.3 At approximately nineteen years of age, a person's brain has reached its heaviest weight, that is, between 1,200 and 1,500 grams, whereas the female brain is significantly lighter than the male one.4 As research has shown, the differences in the size of the brain have no influence on intelligence and can be explained by the variance in body weight of the sexes. Different brain weights between ethnic groups must also be seen as dependent on body weight and height, which are, in turn, dependent on a number of factors.
