Why are a lot of teenagers rude and stupid?

It isnt just teenagers a certain percentage of the population crossing all race age cl and gender are rude and deliberately unintelligent - I guess because it works for them to be arrogant & ignorant.They can make status out of it. so its power of a kind - We aren't a very nice species all round. be glad that you dont understand them that means you're probably free of whatever is driving them