RYA Wokebomb

 exactly, although it seems some people want their particular  sport /. hobby/ pastime to remain solely for 'people like them ' ( Pale , Male, Stale )  

first  two of those characteristics they can;t do much about , but  the staleness is  100 % a choice 

exactly !

I was using the word rationalisation in it's true sense.

If I can give my brief and potted take on prejudice, I have a bit of time:

Humans have the ability to learn dogma. It's a mostly useful ability and is sometimes called rote learning.  A good example would be the times tables which we can quote without thinking and with absolute certainty, learnt from repetition and reinforced with encouragement from teachers. Another form of rote learning would be "don't cross the road without looking and listening", it gets repeated endlessly when we are kids until it finally sticks and becomes an automatic response. In this last example we have learned to pre judge roads as dangerous places, we have applied prejudice and possibly saved our lives.

These are constructive examples of how humans save time in  critical situations, how to make split second decisions with instant automatic responses.

All very useful and it serves the human race well in most instances. The problem arises when we are fed dogma that isn't useful and we then apply prejudice destructively.

This is learnt behaviour and therefore can be unlearnt given a bit of thought and willingness.

Here's the bit that can F**k the willingness to unlearn up:

Humans also have a need to "belong".  We are much better able to survive and thrive in a group. Evolution has imposed this need.  Groups are likely to have more skills than an individual.

There is a need for harmony in these groups otherwise they can become dangerous (ones own sensitivity to fear may make us more or less social)  Humans have developed a whole range of unspoken rules and abilities to get along, one of these abilities can be called Confluence (in some circles), it's mostly an unconscious response, the need to go with the flow, we will adopt common attitudes and behaviour in order to maintain harmony. Better still we will seek out groups that have attitudes that mirror our own. We will be inclined to defend the group also. Whether these attitudes are constructive or destructive is up for debate? Most of this stuff goes on beneath the radar, is unconscious and can be called institutionalised.

In brief:
Pre judging is mostly constructive but quite often isn't. It's learned and can be unlearnt.
The very powerful human need to belong may bugger up and override the desire to un-learn.
There's loads of stuff missing above.
woke?