According to a study performed by researchers in the United Kingdom, playing violent video games can increase pain tolerance for short periods of time. 40 participants were asked to play a gold video game and a violent video games for ten minutes, then proceed to put their hands in a bucket of ice water on two separate occasions. After playing the violent video game, participants were able to keep their hands in the bucket 65% longer. Dr. Richard Stevens explains the violent video game ignites participants "fight or flight responses," which triggers an increase in heart rate and reduces sensitivity to painful stimulus. The study seems fairly reliable as a rather large number of participants were testes. However, it is uncertain if the sample was randomly selected or if the environment of the test was controlled. It's interesting to see there may be benefits from playing violent video games as they are usually criticized by researchers.