Cameroonian kids were part of an experiment based on the classic “marshmallow test”: Put a single treat before a child but tell the child if he or she waits, say, 10 minutes, a second treat will be given.

Cameroonian kids were part of an experiment based on the classic “marshmallow test”: Put a single treat before a child but tell the child if he or she waits, say, 10 minutes, a second treat will be given.