This is inspired by the recent post on /r/science.

The article accompanying the study suggests that bullying behavior is genetically influenced. Though I haven't read the study myself, the article does not address any specific biological evidence supporting this hypothesis, but rather asserts that this may be the case and proposes new ideas to schools to channel bullies' behavior to less harmful activities.

As with any subject, making any judgment calls based on a single paper is unwise, so I was wondering how much biological evidence supports this hypothesis? I personally think that it is entirely plausible, and have no particular feelings about it one way or the other. I'd just to like to know more about it.