In the 1960s, Walter Mischel tested four-year-old children for self-control in "The Marshmallow Test": the children were each given a marshmallow and told that they can eat it anytime they want, but if they waited 15 minutes, they would receive another marshmallow.
1960. aastatel uuris Walter Mischel nelja-aastaste enesekontrolli vahukommi testiga (inglise keeles The Marshmallow Test): igale lapsele anti vahukomm ja öeldi, et nad võivad selle ära süüa millal iganes nad seda soovivad, aga kui nad ootavad 15 minutit, siis saavad nad veel ühe vahukommi.