They also reported how they felt after they cried.
VOA: special.2009.01.28
When the scientists set the same children the marshmallow task at the age of five, they found that the kids who had criedalso struggled to resist the tempting treat.
Imagine if movie producers could not only instantaneously know the age and gender of people in the audience but also in what exact second they laughed, cried or got angry or disappointed.