Pepper Schwartz is AARP's love and relationships ambassador.
When a friend opts to date someone who is old enough to be their parent, a common response is to see if the decision passes the “half their age plus seven” test.
If your love is true, you'll help everyone involved work through these issues and more.
While female users look for men roughly the same age as them (or perhaps a year or two older) men prefer women in their early twenties, regardless of their own age.
While women prefer a small and constant age gap, men are so hooked on the idea of a nubile young partner that they prefer a larger age gap the older they get. In theory there are plenty of reasons to favour a small age gap.
The ability of both members of a couple to sing a favourite childhood television theme tune could bond them together, at the risk of irritating those nearby.
And sharing the joy of getting a free bus pass at a similar time, or saving money from combining big birthday parties, is clearly attractive.
The rule, whose origins remain mysterious, has been passed down through generations as a way of justifying or, more commonly, pouring scorn on other people’s couplings.
It’s fine for a 22-year-old to go out with an 18-year-old.
Perhaps the best known are 68-year-old Michael Douglas and 43-year-old Catherine Zeta-Jones, who have bridged their quarter-century age gap to stand by each other through a long partnership (and some recent serious health scares).
Or look at 65-year-old Rolling Stones guitarist Ronnie Wood, who made 34-year-old theater producer Sally Humphreys his (third) bride in December 2012.
It’s not for a 38-year-old to go out with a 23-year-old, however a 26-year-old would be fair game.