When my older sons were younger they watched wrestling but not at age 4. I think you should trust your judgement. If the child cannot handle the program, and if he already has behavior issues, then he shouldn't be watching wrestling.

I think that we have to be very careful about what our pre-schoolers are exposed to. Get him some books and some crayons and paper and have some family interaction writing letters and reading them to one another! Board games also help develop literacy skills.

Good luck!