[Tallguy]

He should do a study of wife’s breast-size and its relation to male marital happiness.

That's a far more complex social interraction and not subject to a straight-forward test. Part of what these studies do is they attempt to boil away all other factors to test for just one thing. It's not always possible.

Here we have a social interaction between people that we don't expect to know eachother on a personal-level: the customer & the waitress. AND we have a handy measuring-stick -- the size of the tip. Reading how these studies are constructed can be pretty interesting stuff.

[Behind Liberal Lines]

He should do a study of wife’s breast-size and its relation to male marital happiness.

That's a far more complex social interraction and not subject to a straight-forward test.

...and, arguably, already answered by the classic Jimmy Soul R&B record "If you want to be happy for the rest of your life, never make a pretty woman your wife."