[xenophanes]

People like similar people. They have more in common. Relationships between similar status people end up happiest and work out the best, on average.

That doesn't mean people always hit on those of equal attractiveness alone. If you have more money than the girl, then she can have more prettiness. But if she's way ahead on looks, you better be way ahead on money or something or it isn't an equal relationship.

What does this add up to? Simply: the edge of the bell curve is always lonely.