J T McIntosh (1925 - 2008)

J. T. McIntosh was the pseudonym used by Scottish writer and journalist James Murdoch MacGregor, under which all of his SF writing appeared (with the exception of a single story). Born in Paisley, Scotland, in 1925, he began publishing science fiction in 1950 with 'The Curfew Tolls', which appeared in John W. Campbell's Astounding Science Fiction magazine. His first novel, World Out of Mind, appeared three years later, and he continued to write novels of interest over the next decade and a half, but ceased publishing work after 1980. He died in 2008.

Earth, 2066.
The human race was changing...nature was trying valiantly to produce an answer to the neurosis, psychosis and instability of mankind; and so, two new breeds of homo sapiens were emerging - the Normans, originally called Newmen, and the Sexons.
Normans were absolutely devoid of body hair, with quiet, thoughtful dispositions hiding a new ability, a new power, which had previously been granted only to a chosen few.
Sexons were completely the opposite, being unstable, animal-like in their desire for sex, often violent and sometimes depraved.
And so the blueprint of man was being changed, with each mutation desperately convinced of its right to inherit the Earth...