Why can some people only get off on feeding their frustrations through cruelty?

My name is Craig. It's a hassle changing adult diapers for me. It can get pretty messy at times and it's hard to deal with it when you're like 40 ft from the washroom. What should I do?
Why do you think some people struggle to be kind, and how does understanding them change your perspective on kindness?
Does a truth speaker rely more on their logical mind than on their emotions?