I was just watching The Simpsons (one of the Halloween specials) where Lisa's reading an Edgar Allan Poe and Bart comments that it's not scary.... Lisa points out that people were easier to scare back then and Bart retorts with a comment about Nightmare on Elm Street.
You know, we've all had this thought before (i'm sure) and we know that films that were banned or hated because of their controversy 20 or 30 years ago might even get a 15 age rating if released today! Now, the reason this happens is that society gets used to things; people adjust - but only if that something is experienced on a large enough scale.
People, on the whole, are less scared by specific things than they were 100 years ago because they have been experienced and/or understood. The people in England, thanks to the bombs dropped in WW2 and the terrorist bombs used by the IRA, are less scared of attack by foreign and terrorist means. All the 'anti-terrorist' government propaganda in the recent years in the US has lead from outright fear to cynicism and the response is becoming more level-headed as time goes on (not just in the US).
Thinking along these lines, if real events and false events (films, literature, propaganda etc) can positively affect a population, can games also positively affect our response to certain situations?
At the moment though i'm having a hard time thinking of a game that actually can increase our tolerance or general wisdom. Maybe it's just one more step on the road to getting gaming's 'Citizen Kane': we have the good, immersive stories, the interesting interative/gameplay mechanics.... but where are the allegories, the thought provoking and personally challenging experiences?
I know that some people might argue that Call of Duty 4 (and other recent games) provides this.... though i don't think the game really does. I think it provides an insightful look at the effects of war in some instances but it was so hand-holding and directed that it comes closer to what a movie can provide rather than the individual experience that a game could provide.