Grandparents are a relatively new phenomenon, researchers said today.
Until around 30,000 years ago, mankind’s ancestors had lifespans that were too short for three generations to live side-by-side, according to a study.
Simply, most people died before they were old enough to have grandchildren.
Scientists said their findings show that once life expectancy began to grow, populations expanded and societies started to thrive.
A long-running research project, studying the fossils of proto-humans stretching back three million years, reported some of its findings in the magazine Scientific American.
Anthropologist Rachel Caspari said that by examining Neanderthal dental records, her team established that 130,000 years ago, ‘no-one survived past 30’, which was the age at which they would have become grandparents.
The study, which involves fossil remains from 768 individuals, has been calculating the ratio of older to younger adults in ancient human societies down the millennia.
In the Neanderthal culture there were just four adults past the age of 30 for every 10 young adults. The average life expectancy was between 15 and 30. Read more.