Do you think that some but not all people involved in Professional Sports have higher than average violent tendencies?

What are your thoughts on?
They are just born that way.
Having to be so competitive makes them that way?
Supplements taken to enhance performance cause them to be more violent.
They were bullies in school and continue to be bullies.
Explain another reason in comments
Select gender and age to cast your vote:
Do you think that some but not all people involved in Professional Sports have higher than average violent tendencies?
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