This time around, Twenge and her team make a point of saying that they are not trying to establish causes as such, but that they are assessing the plausibility of potential causes.

Let's assume that it's impossible not to be fooled at least some of the time - that when assessing patients' sincerity, we should expect a certain rate of false positives.

Most studies to date have offered only snapshots of child health, assessing the short-term impact of hunger over a given period of time.