Stupidity is a lack of intelligence, understanding, reason, wit, or sense. It may be innate, assumed, or reactive - "being 'stupid with grief' as a defence against psychological trauma a state marked with "grief and despair...making even simple daily tasks a hardship."
These are the basic symptoms of the human stupidity complex.
- Being irrational with the way a relationship is going downhill and ruins it.
- Sticking a body part into a dangerous place.