The American Academy of Pediatrics' (AAP) Healthy Children website notes
that television violence can actually lead to real-world violent acts.
According to the AAP, by the time that your child reaches his teen years
he probably will have seen roughly 8,000 murders in the course of
watching TV programs. Although your teen has the cognitive abilities to
reason that televised violence is fantasy -- unlike a younger child who
may not understand this or the consequences of violence -- the constant
bombardment of violence may desensitize him to these acts or even make
them seem intriguing, in an exciting way.