The Pew Research Center thanks Margaret Usdansky of Syracuse University for her contribution in the initial planning of the project and her exploration of the American Time Use Survey data and Suzanne Bianchi of University of California, Los Angeles for her insights in historical time use surveys and her expertise in time use research. Gretchen Livingston and Rick Fry, both senior researchers at Pew Research’s Hispanic Center, contributed economic and demographic research for the report. Cary Funk, Senior Researcher at Pew Research’s Forum on Religion and Public Life, helped with data analysis.
In the studies Mischel and 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 and chose to wait for the more desirable reward. However, Mischel's earlier studies showed there are many other situations in which children cannot be certain that they would receive the delayed outcome.     In such situations, waiting for delayed rewards may not be an adaptive response.