After many tests and hundreds of hours of research Walter come to understand that it was about how one used his or her attention. If the child sat and looked at the marshmallow they wouldn't be able to wait very long but if the child instead distracted themselves with something they could wait.
Walter's would also do tests on toddlers by taking them away from their mothers and found similar results. Some children would cry or get emotional when took away from their mother while other's wouldn't. The ones