I think online gaming is particularly useful, and telling, because you can factor out all other variables. Anything from clothes, body language, personal preferences, race, class, etc. Because you can use the exact same person for all interactions and just change their username, or change their voice to make them sound male or female. So the players can actually be interacting with the same person playing the game the same way, just with a male name/voice and then switch to a female name/voice and see how behavior changes. This confines the likelihood of why there was a change to the perceived gender of the player. Can even switch male players and female players and have each play both genders. Hard to do that in any other format.