Why do we keep ourselves ignorant?

Deborah Danan asks an interesting question in her article: 

It seems obvious to most civilized people: Ignorance is the mother of conflict and educating ourselves about “the other” is key to building healthy societies et cetera et cetera. 
But if it’s so obvious, then why is it not a primary focus—if not the primary focus—of our leaders, both spiritual and political? 

There are at least a few reasons why leaders and everyone else seem to steer themselves away from learning more.  One is unintentional, the other deliberate.

Humans categorize.  We have to.  There is simply no way for the human brain to work unless we group things together and reduce information to general properties and traits.  For example, I categorize the coffee holder on my desk to be a cup.  It is specifically a mug, but it also falls into the category of cup.

The reason why we do this is so that we do not have to consider each and every instance of a thing as unique on its own.  We can do it.  I can look at each and every cup as its own unique entity.

But I can also generalize.  I can point to certain properties that a cup has, and such properties manifest themselves on other objects.  Thus I can categorize objects that share such properties as "cups."
We do this with people as well.  We categorize people based on look, clothing, ideas, and a variety of things.

There is a legitimacy to this.  If I am walking down the street at night and I happen upon a bunch of tattooed individuals with piercings and ripped clothing, I'm going to avoid or at least keep alert around them for fear of being robbed at gunpoint.  For all I know they might be the local Catholic Knights of Columbus chapter heading off to a late Mass.  But that doesn't change the fact that given there appearance and no other information, I'm going to be more cautious.  For another example, if I am walking down the same street and I see a bunch of balding men in suits and ties, I can assume they are bankers or investors.  I may be robbed legally by them later, but at least I do not have the fear of being robbed at gunpoint at the moment of passing.

But obviously this categorization can backfire.  In my previous examples, the tattooed guys could be saints and the suits could be mafia.  I simply don't know.  But in order to preserve my health and safety I would be an idiot not to exercise caution given the information I currently have.  It does however hinder knowledge.  Assuming both my conclusions are wrong I have misjudged the situation.

Knowing when to categorize and when not to is actually quite difficult.  Given the limited knowledge we have at any given time, we nevertheless still need to make judgments about our situations and duties.  And in my previous examples, categorization is my only option at the point of contact.  This is why while my knowledge is deficient regarding the encounters I am left with little choice in that regard.

This is the unintentional aspect of being ignorant.  The circumstances in the case above do not permit me to draw an accurate picture, nor do they allow me to correct this.  The intentional way we keep ourselves ignorant is for another post.