Certainly we don't need a study to prove that people generally date people who are similar to themselves. There's that old joke that if couples are together long enough they start to look like each other. I fail to see though how this relates in anyway to your argument that modern relationship formation/dating has everything to do with Darwinian style theories on natural selection applied to human social behavior. Again, you seem to be making a completely different point here, which is that like attracts like. In any case, this doesn't seem to have anything to do with my main point: a second date after a decent first date is not unreasonable.
see the review