Preschoolers are remarkable for knowing when to “flex their muscles”, as shown in the famous Marshmallow Study in the 1960’s where preschoolers had to decide whether to eat a marshmallow immediately, or wait fifteen minutes to get yet another marshmallow. In follow up studies, the four year olds who resisted eating the marshmallow were found to have increased SAT scores and lead healthier, more successful lives than their counterparts who lacked willpower. For years scientists believed that self control was a predetermined trait that remained stable throughout a lifetime, and that trait was evident as young as preschool age. However, a 2012 Rochester study found the reason children lack self control is not because of lack of a unitary trait needed to succeed, but because of lack of trust in the outcome of waiting.