When I have children this is going to be part of the daily dining ritual. This is an apparently famous little social experiment. The kids get two marshmallows if they can not eat the first one for a few minutes.
I reckon the game would be more fun if you didn’t let the kid have the first marshmallow after they waited. That would be a life lesson.
I also want to teach my children that red is blue – like one of my friends did to her little brother (I can’t remember the colours she used).