Can you fill me in on something?

What things do people do that's considered sick besided serial killer or child/animal abuser/molester? My brother told me something about my nephew doing something sick & how my nephew ruined the whole family, & so I guessed it could've been child molestation or murder. He thought I had my mind in the gutter. What else could be considered sick besides murder, , etc. I thought those were the only 2 types of things that would consider you a sicko. I know I'm undeducated on a lot of things.