The Legendary Dragon Alephwyr, named Alephwyr, BA

What’s the best modern theory of what turns people into bullies? Is there any truth to the movie trope that it’s a sort of punch-down cascade due to being abused at home? That seems very unconvincing to me. It feels like at best one kind of etiology that accounts for a fraction.

I’ve known bullies with mild-mannered weak parents and no visible bigger-bully in their environment. The more plausible general mechanism seems to me to be that people develop an addiction to intimidation/brute force as an easy way to get what they want.