self-imposed delay paradigm, were described more than 10 years later by their parents as adolescents who were significantly more competent." A second follow-up study, in 1990, showed that the ability to delay gratification also correlated with higher SAT scores. A 2006 paper to which Mischel contributed reports a similar experiment, this time relating ability to delay in order to receive a cookie (at age 4) and reaction time on a go/no go task. A 2011 brain imaging study of a sample from the original Stanford participants when they reached mid-life showed key differences between those with high delay times and those with low delay times in two areas: the prefrontal cortex (more active in high delayers) and the ventral striatum, (more active in low delayers) when they were trying to control their responses to alluring temptations. A 2012 study at the University of Rochester (with a smaller N= 28) altered the experiment by dividing children into two groups: one group was given a broken promise before the marshmallow test was conducted (the unreliable tester group), and the second group had a fulfilled promise before their marshmallow test (the reliable tester group). The reliable tester group waited up to four times longer (12 min) than the unreliable tester group for the second marshmallow to appear. The authors argue that this calls into question the original interpretation of self-control as the critical factor in children's performance, since self-control should predict ability to wait, not strategic waiting when it makes sense. Prior to the marshmallow experiment at Stanford, Walter Mischel had shown that the child's belief that the promised delayed rewards would actually be delivered is an important determinant of the choice to delay, but his later experiments did not take this factor into account or control for individual variation in beliefs about reliability when reporting correlations with life successes. In the studies Mischel and his colleagues conducted at Stanford University, in order to establish trust that the experimenter would return, at the beginning of the "marshmallow test" children first engaged in a game in which they summoned the experimenter back by ringing a bell; the actual waiting portion of the experiment did not start until after the children clearly understood that the experimenter would keep the promise. Participants of the original studies at the Bing School at Stanford University appeared to have no doubt that they would receive a reward after waiting