Go to a convention. Walk into the board game room and notice the average weight of the participant, their general apparel, the presence of body odor, if their marital status is normal for their age(30+ married) and after speaking to them their level of professional accomplishment (40 year old CPA as opposed to 40 year old pizza delivery boy).

Now walk into a pen and paper room and a LARP room. Make your same observations. While these are very crude measurements, if you were to do this I think that you would find statistically significant differences between these populations.

Of course if you were to compare these same stats as opposed to the average person walking down the street you would find that all three groups deviate in statistically significant ways from the norm.

These are obviously just my personal observations, but pcmn seems to agree as well. I have also heard other gamers voice these same observations, though typically only in private conversations.

Edit: Just to clarify there is nothing wrong with LARPing and in fact if I was near your group I may even be interested given the right circumstances. I just don't ignore true statements even if they are offensive to myself or a group that I may be part of.