"Increasingly violent behaviour"? You need to change newspapers - violent crime has been falling for years. Violent crime recorded by the police is down 8% since last year and violent crime recorded in the British Crime Survey is down 12% since last year. See this BBC News article for all the non-gory details:
Recorded crime figures show fall
Are computer games responsible for this fall? No. Increasing standards of living are. The end.
Regards