The marriage between Sarah Michelle Gellar and Freddie Prinze Jnr should have more legs than the union of Ashton Kutcher and Demi Moore.
That's if you believe a group of 'experts' who's new research says couples with smaller age gap are better off. (The Prinzes have a one year gap, the Kutchers have 16 years).
Researchers report the optimum difference in digits is five years. The woman should be the younger one.
She should also be 27 per cent more intelligent and both should come from similar cultural backgrounds.
Based on these findings, here are some couples we're not surprised went belly up:
Whitney Houston and Bobby Brown - We're not sure who was smarter as there were allegations both wasted a fair amount of brain cells, but while they had similar roots - they still had that 16 year age gap.
Madonna / Guy Ritchie - perhaps it was the 10 year age gap that put the dampener on this relationship. Maybe it was the fact she could beat him hands down in an arm wrestle.
Jessica Simpson / Nick Lachey - the Newlyweds had a seven year age gap and we're certain she wasn't the more intelligent one in the relationship (although you can get chicken in a can now - so perhaps Jess is really a Nostradamus)