I’ve recently been playing variations (960, bullet and blitz) all of which I have a lower rating - sometimes much lower. What is strange is that by now what level player I am but if I see a player rated much higher than my ‘new’ and thus less accurate rating suggests but lower than what I know I really am, I play worse expecting to lose – even if he is lower than my ‘real’ rating. I think this psychology could be extended to my 'normal' games (i.e. the method I prefer – online) if I ignore the ratings (easier said than done) or even better, imagine them to be in my favour.
In short, I lay better when I think I’m going to play better and vice versa.