Although it’s ostensibly about WoW, this post from Terra Nova: “Our avatars, ourselves”, makes some great observations how we relate to (and interact with) stimuli in virtual worlds in general, specifically our and others’ avatars.
In brief, research to this point indicates we react to virtual stimuli exactly the same way as if it were real — for example, we don’t want our characters standing too close to other characters, because it’s a social convention in the real world that we all have our own individual space. ((This is particularly notable in WoW, where there is no “body buffer” as there is in CoH, and it’s possible to actually stand ‘inside’ or walk through people, but people go to GREAT (if unconscious) effort to prevent that from happening if at all possible.))
Also (and obviously) we react positively to attractive avatars, more ‘upbeat’ locales, environment conditions, and surroundings. Again, I’ve seen this. The avatar example is easy to see — there are toons whose abilities I really like, but whom I don’t play simply because I don’t like looking at them much (Zero at the Bone, or any undead WoW character) — but I know there are areas in both CoH and WoW I just won’t want to linger for long (they’re DEPRESSING), while others I enjoy (Talos waterfalls are neat, and there’s something very relaxing about doing some deep sea hunting with a potion of water breathing for a few hours.
As they say in the post, “You can take the person out of the real, but not the real out of the person.”