Women live longer than men because their bodies are better at repairing themselves. In an article in November’s Scientific American, Professor Tom Kirkwood of Newcastle University argues that women have to be better at fixing the wear and tear on their cells in order to have healthy offspring.

In interviews last week, Kirkwood said that it made biological sense for men to be more disposable and therefore die younger. The body is disposable, argues Kirkwood, because the genes are passed to the next generation.

“This theory is widely accepted now,” Kirkwood says. “Ageing is not driven by a clock.”