Though DejaMorgana’s write up seems to be written for more of a comedic sense, the black and white concept of the either 1-marshmallow or 2-mashmallow person is flawed, because it has left out the various shades of gray that are caused by the complexity of human emotion. My understanding of humans has lead me to these categories for the 2-marshmallow person, depending on the assumption that all of the marshmallows are identical.
Type A - The person has waited for their second marshmallow, and is happy with the result.
Type B - The person has waited for their second marshmallow, but is frustrated with the result. There are more productive ways to spend ten minutes.
Type C - The person has waited for their second marshmallow, but is frustrated with the result. The first marshmallow was unique. This rarity gave it more, and the impending consumption would be more pleasurable. But with the introduction of the second marshmallow, the first loses a bit of its value, and equally the second is even less valuable than the first.
Type D - The person has never had a marshmallow before, but quickly finds out that the odd taste and consistency of marshmallows is displeasing to them, and so they don’t eat the second. This person will immediately turn into a Type B.
The conclusion from these different categories is not really much different than studying the first set. Humans can react differently given a situation. The same human may react differently with each trial as well.
Personally I would probably have been a Type A at first, but within a few minutes would have become a Type B realizing I could have had my first marshmallow and gone on with my life.