But why wait until grade school? These inhibitory circuits start to develop from birth. Walter Mischel taught four-year-olds how to resist those luscious marshmallows by seeing them differently—for example, focusing on their color. And Mischel is the first to say that even a four-year-old who just can’t wait and grabs the marshmallow right off the bat can still learn to delay gratification—impulsivity is not necessarily something he’s stuck with for life.
