The exact way in which people's attitudes and behaviour are connected remains a mystery. All we can say with certainty is that people are frequently extremely inconsistent.

What about people who do something totally contradictory to their normal behaviour?
I thought it was to do with attitude being learnt and behaviour a response to a perceived need. No expert though.

Maybe what they say is what they want themselves to actually do, but follow what the society has told is the normal behavior (because majority is doing something it must be right).

I just clipped another article about why and how we lie to ourselves. I think we mainly do this to make our lives seem less complicated. We want to be able to be at peace with the way we behave. When our behaviour is not the kind we encourage in general, we have to find ways in which it fits into our beliefs or change our convictions in order to be able to be at ease with our behaviour.