Mothers of twins, you rule. Genetically speaking, at least. Utah researchers have concluded that moms who give birth to twins live longer than mothers who have kids at a measly one-at-a-time rate, reports Discover. Moms of twins also generally give birth to more kids, even when not counting the twins. The research flips a long-standing theory that having twins is an evolutionary accident and instead makes the case that women of the hardiest stock give birth to twins because they can.
The previous theory held that twins were a "bet-hedging strategy gone wrong," explains Discover: Only the strongest of the eggs was supposed to have survived, but it somehow battled to a draw with another. The new research, based on exhaustive data from Utah families in the 19th century, sees the notion of twins instead as "an opportunistic strategy—an evolutionary ace card, played by mothers in good condition, when times are plentiful," notes Discover.