Cognitive biases...

Cognitive biases...  This is a good collection of them, with easily understood descriptions. 

I've long noted that most people are completely unaware of these biases, though they'll readily recognize them when confronted with descriptions like those at the link above.

One thing that article doesn't mention is that people vary widely in their susceptibility to each of the biases.  For instance, in general introverts are much less susceptible to in-group bias.  I knew the late Dr. Alan Davidson, an industrial psychologist, quite well.  He and I had a fascinating conversation once about efforts to predict people's success by measuring their cognitive biases.  He believed that this effort, if made practical, was the only real contender to using IQ as a predictor of success.  At the time he and I had that conversation, about 15 years ago, the major finding so far was that successful people had much lower cognitive biases of certain types – and higher for other types.  For me, at least, that's a completely counter-intuitive result!