As Matthew McConaughey said in Dazed and Confused….

New Scientist says old dudes like Charles Darwin really should be shacked up with younger women like Scarlett Johansen because of science. Humans, they say, are primed for May/December pairings by evolution:

Statistics show that monogamous men have the most children if they marry women younger than themselves. How much younger is the key question.

Last year, a study of Swedish census information suggested a 4 to 6-year age gap is best, but new research has found that in some circumstances a surprisingly large gap – 15 years – is the optimum.

Martin Fieder at the University of Vienna and Susanne Huber of the University of Veterinary Medicine, also in Vienna, Austria, studied the Swedish data and found that a simple equation related the age difference of the parents to the number of offspring. For people who had maintained monogamous relationships throughout adulthood, the most children were found in couples where the man was 4.0 to 5.9 years older than the woman.

OK, so “nearly 6 years” isn’t exactly May/December, but still.