I don't know. I don't think it's a matter of being specifically taught to downplay positive reiforcement. I think there are many, many factors involved in creating a negative self-image, most of which are environmental in nature. I think a lot of it has to do with the environment we were immersed in during our formative years.

At any rate...

My gut feeling tells me that you brush off compliments because you don't feel worthy of them... and that you don't think you're as good as people think. I suspect that you fear that some day the people that complimented you will find out that they were wrong... and you'll be found out as being a fraud by accepting their compliments and praise... that you accepted something you weren't worthy of. I think that in your mind it's much better to keep telling yourself that you aren't worthy of praise so you won't ever have to feel like you were mislead into believing something that wasn't true. I think that in your mind, when people eventually find out that you aren't as good as they think, it'll be much easier for you to be able to tell them, "SEE! I told you I wasn't as good as you thought I was! I told you that you were wrong about me!"

I think you need to give yourself that escape route... one that allows you to validate the fact that you aren't good enough... and that you told everybody you weren't when you didn't accept their compliment.

So, when someone tells you that you're sexy and beautiful, you're sure that they'll find out some day that your aren't sexy and you aren't beautiful...so you feel the need to set them straight... and not accept a compliment that might set you up for being a fraud... By not accepting a compliment you've created an out for yourself. You can tell them that you TOLD them they got it all wrong about you when you didn't accept their compliment!

OR

It's very possible... nay... PROBABLE, that I'm completely full of prunes and everything I just spewed was utter rubbish!

Dan