Since their emergence in the 1970s, video games have evolved in line with progressive developments in technology. The impact and success of video games should not be underestimated. For example, in 1993 it was estimated that, globally, games revenue exceeded $10bn.

Since their emergence in the 1970s, video games have evolved in line with progressive developments in technology. The impact and success of video games should not be underestimated. For example, in 1993 it was estimated that, globally, games revenue exceeded $10bn.

It is broadly accepted that the majority of game players are young, not least by the games industry which caters, almost exclusively, for a younger age range. A 1997 survey showed that more than 75 per cent of a large sample of 11- to 16-year-olds played video games on a daily basis for between one and one-and-a-half hours. Thus it appears that video games have become firmly embedded within popular youth culture.

Given that they have a well-established role in the entertainment industry, it is surprising that they have received relatively little attention from the research community. At present there is only a limited body of research on video-game effects. Experimental studies examining the effects of video- game play on aggression have tended to focus on either very young children or adult samples. Consequently, research with adolescent game-players is virtually non-existent and evidence relating to video-game effects in this age group represents a significant gap in the psychological research literature.

My paper outlines the findings of two studies carried out among 12- to 16-year-olds. The first study examined which features of video-game play predict game enjoyment. A number of important aspects of video-game play were identified: the graphics, story line, violence, and the level of difficulty. The most important predictors of game enjoyment were excitement and playability.

However, more interestingly, game violence was one of the poorest predictors of game enjoyment. This finding helps to dispel the myth that only violent games are enjoyable. Thus, given that the majority of games contain violence, it appears that their popularity is more likely to be a result of limited choice than game players showing a genuine preference for violent game play.

My second study examined short-term effects of violent video-game play on feelings of hostility, anger and anxiety in 12- to 16-year-olds. A violent martial-arts game and non-violent racing game were selected for the experiment. These differed significantly in violent content but were accurately matched on all the other important game dimensions.

Prior to game play, the participants rated their mood on a number of dimensions, including hostility, anger and anxiety, before being randomly assigned to play either a violent or non-violent video game for 40 minutes. Immediately after game play, they were asked to report how they were feeling for a second time in order to analyse changes in mood state that were elicited by game play.

The results showed that hostility, anger and anxiety were significantly enhanced following violent video-game play compared to non-violent video game play. In addition, however, there was some (though weaker) evidence that the non-violent video game also enhanced hostility in the game-players.

Thus, while game violence does seem to enhance aggression-related mood states, alterations in mood after game play cannot be accounted for, solely, as a function of the violent content. Other aspects of game play that have the capacity to induce hostility in the player need to be explored. One likely possibility is that high game pace may increase arousal in players which is then subjectively labelled as hostility.

In conclusion, my research provides some evidence that violent video- game play can elicit short-term effects on aggression-related mood states in the adolescent video-game player. However, these effects cannot be explained as being caused solely by violent content in video games.