What is a hallmark characteristic of a stupid person?

@NearMiss: You're still butthurt about it. Because you seem not to realise there are cultural differences. You even got a wiki link showing why Europeans call something a biscuit and you were banging on about how the English do not have a biscuit.
You need to find a different hobby than jump into my responses with your sore butt..every fuckin' time.
Get some salve, if you do not find relief minding your own business.