Actually, keyne and I had the same reaction: wondering if the experiment takes into account the boredom factor. How long are those kids in that room with nothing else to DO but eat the marshmallow sitting in front of them? :-)
I'm not smart enough to decide if that represents a factor that actually affects the experiment, but it seems like something that should at least be acknowledged.
Yes, it's a factor. I just downloaded a copy of Mischel et al 1989, which talks about some follow-ups. They played with whether they kids would see the rewards-- both the preferred and the less-preferred and also what they were told to think about. If they weren't told to think about anything, then seeing the rewards made it harder. If they're told to think about the reward (i.e. "think about how great it will be to have TWO marshmallows!") then seeing them or not didn't make a difference, but wait times were shorter (i.e. more giving up). But, like you way, if they were told to think about unrelated fun things, it also didn't matter if they could see the rewards or not, but wait times were longer.
(I should note that in the studies, the kids ring the bell to end the study and "give up" and get the dispreferred, rather than just eating the treat, since it's not always an eating-treat, sometimes it was a toy, etc.)
no subject
I'm not smart enough to decide if that represents a factor that actually affects the experiment, but it seems like something that should at least be acknowledged.
no subject
(I should note that in the studies, the kids ring the bell to end the study and "give up" and get the dispreferred, rather than just eating the treat, since it's not always an eating-treat, sometimes it was a toy, etc.)