There’s plenty of nuance to be had in Richard G. Bribiescas’s examination of the discrepancy of average lifespans between women and men. But really, it’s largely because young men die at higher rates than young women.
Bribiescas lays this all at the feet of testosterone and natural selection. You see, the two have an interesting relationship. Given how reproduction works, natural selection doesn’t really care about how old you can live. It favors those who can pass on their genes, not so much those who live to see their genes pass on their genes. Testosterone, generally, makes you thin and strong and encourages risky behavior — all qualities that, well, lend themselves to passing genes on.
The trouble is, while testosterone might help the young men get laid, it also nudges them closer to the abyss of death. Being thin and strong and unafraid of risk, statistically, will make you more likely to die.