In " A Hot/Cool-System Analysis of Delay of Gratification: Dynamics of Willpower", Mischel,et al further explains the "two systems" theory he mentioned in his article of "Delay of Gratification in Children". In "Delay of Gratification in Children", Mischel proposed the idea of two different stimuli such as hot and cool stimuli, he argues these two different type of stimuli affect the children's delay behavior significantly. They explains hot and cool systems connecting with children's will power control when facing different systems in " A Hot/Cool-System Analysis of Delay of Gratification: Dynamics of Willpower". Using the same research example(the food treat test) they conducted in "Delay of Gratification in Children", Mischel and his team
