5 year old now teasing pets

I'm looking for some insight to a problem with my nephew. Last year he attended a pool party with some other children, one of who did something to him and the next thing his mother knew, he was holding the other child under water and would not let go until his mom made him. When questioned, he didn't see anything really wrong with what he had done to the other child. After he started school this year, his teacher notifed his mother that he was disrupting the class, not doing his activities and mocking her when she was talking to the class. Once again, when questioned, he saw nothing wrong with what he was doing.
Now he's started teasing his grandmother's pet dog by laying on the floor, staring at the animal, and then slowly edging forward until the dog growls or snaps at him. He's been repeatedly told not to do that and has been punished for doing it by loosing priveleges, and he just laughs and thinks its funny to torment the dog. Five minutes after being punished, he's right back at teasing the dog again. What is the matter with this child? His mother and grandmother think he cannot connect cause and effect of his actions his mind. That he can't see beyond the 'here and now' to see what might be the outcome even a few seconds into the future.  I'm not so sure its as simple as this child not thinking about what he's doing before he does it. The fact that his supervising adults correct him repeatedly for the same things is bad enough, but now he's showing aggression towards a pet. Has any one else had this problem?

[Kevin Kennedy, Ph.D.]

Five year olds are famous for problems with impulse control. They are beginning to grasp cause-and-effect relationships, and this occurs chiefly through experience as thie cognitive abilities increase. This situation does not sound extremely atypical.

[samchic04]

Sometimes to get a straight answer, you have to kind of stoop to their level. My daughter is 3 and apparently she doesn't think what she does is wrong, so I switched it up a bit. When she does something and finds it hilarious I say "wow, that must have been really fun for you huh. Can you explain it to me so I can laugh too?". I've also learned to not be accusing. Instead of "why did you do that??" try " what happened?", making it seem less like an attack on him. This works great with my 3yo as she knocks her little brother and tries to hide/lie about it. Good luck!!