Back in 1943 psychologist Abraham Maslow published his theory that human decision-making is based on a hierarchy of psychological needs, from the most basic physiological requirements — food, water, shelter, rest, reproduction — all the way up to the more sophisticated forms of self-actualization pursued by affluent moderns habituated to having all their ‘lower-tier’ desires met. You may be familiar with the concept.
We will not linger over the details of Maslow’s little flow-pyramid and the pursuit of normal human desires. What’s important about it for our purposes is the observation that identical circumstances can produce very different responses in different people depending on what is important to them. The exact same test can produce very different results in different subjects.