My boy is 10 and has got very interested in Pocamon cards. ( a game
way to complicated for me to understand) But I've also noticed it's
linked to a computer game...
value people's opinion on whether, you think video games cause bad
behaviour in kids.
My three daughters (And their boyfriends when they got older) were very much into Pokemon and I understand your concern. On the surface, it does appear like cockfighting, but I would point out that it is a Japanese game heavily laced with Asian martial arts philosophy where confrontation in the vehicle through which we learn and grow.
In this mythical universe, preventing that sort of confrontation results in arrested development where the animal (The Pokemon) never grows or gets any stronger.
Whether this adversely affects Western children or not depends entirely on whether they understand the cultural context in which it originated. I don't think ten is too young, but you know your son better than I do.
As far as more violent video games go, as in would I let a ten-year-old play the Left For Dead franchise? Absolutely not.