Well, ugly women have more to prove. Yes social pressure, if they settle for somebody that looks like some of you guys

, she will be considered less valuable by the surrounding men and women.
where the guys say "what are you doing with him" the women will say "shes with a loser, she must be a loser too"
so the ugly woman doesnt let that happen.
Plus ugly women are more suspicious. They are used to being used and often are very guarded.
Hot women on the other hand, can take any guy they feel like. Nobody is going to frown upon a hot chick who hangs with an ugly dude, because its a fact, shes hot nobody will deny this. Same thing for her friends, they wont think less of her,c ause they already know what she can get.
So sometimes, and not all the time, a hot woman may be easier to get than an ugly one, and most times, neither are very easy to get.
best off trying your skills with women in your league. not ugly, not hot, right in the middle. Then everybody expects you to be together and there ar eno hangups.
This is until u get so good at it, that you can get anything you want, anytime.
The difference here is that while you say there is a difference in women based on their "beauty", I say there is a difference in our attitude towards them. You cant just assume that a woman has a certain mindset or attitude based on beauty. What you can do is to change the way you yourself interact with her and make sure you dont base your own behaviour based on how hot she is.