David Bainbridge says this means older men and women have become perfectly adapted to help their families and society without the burden of raising children.
And while some aspects of the human body decline with age, important attributes such as brainpower are at least as keen in a person’s 40s and 50s as they were decades earlier.
“People below 40 worry about reaching middle age, which I think is very sad,” Bainbridge writes in his book Middle Age: A Natural History.
He adds that mature women and men have such complex and intertwined roles in society that they are “the most impressive living things yet produced by natural selection.”
Humans are the only species to stop breeding long before they die, usually remaining healthy for at least another 20 years.
Bainbridge concludes that this provides an evolutionary boost in which middle-aged people can teach children and young adults important skills and perspectives to advance the species ... if they listen.