Destroyers.

It's more than instinct.
It's a science.
Few people actually learn it formally; as sciences go it's a well-kept secret.
Most practitioners are self-taught.

The science is psychological, and the purpose is to destroy intelligence itself.

This is done by poison; poison thrown into casual social interaction, poison which is hidden, so as to create fools, or if noticed, so as to face normal people with a choice.

The choice? Simply put, this is whether to react or not. Reaction is usually suppressed by habit, it is simply too much trouble to call every bastard out on his poisonous, mentally destructive behaviour.
No.
The real choice is much easier.

All we have to do is reject the poisoner in their entirety. Leave them alone with their lack of self-esteem, leave them alone with their crappy 'science', leave them alone.

This is when, often, they become twice as sweet, twice as proper, in order to sugar coat the poison.
That is the mark of a real bastard; they attempt to dehumanise our choice, in order to make us appear unreasonable. Fortunately we can depend on convention to pay them precisely as much attention as they deserve, no more.

British insularity? Now you know.