When I mention conditioning, I mean from a very young age.
For example: Throw salt over your shoulder if you spill some -or- Green skinned people are bad and you should never trust them or allow them in your neighborhood.
Now the former is pretty harmless but not so the latter. In both cases the only explanation is "that's how I was raised" which I don't find compelling or rational.
I think part of the problem is that most people are conditioned into many beliefs from a young age
I know a guy who hates foo (using a place holder). In fact he's downright foophobic. He is pretty convinced he has a natural unbiased hate of foo and is being rational when he expresses it.
To me as an outsider it is pretty obvious that his hate of foo is the result of cultural conditioning. To him it is perfectly rational to hate foo and to me it is totally irrational, especially since he can't give any concrete reason for it.