The most powerful source of stress for humans is the possibility of being judged negatively by others. As the epidemiologist explains, this social anxiety acts directly on our bodies and minds, providing the basis for some of our most irrational and unjust tendencies.

Question: Why are humans prone to developing unequal societies?

Kate Pickett: Well, I think we’ve lived in every kind of society. I mean, for a lot of our existence as human beings, we’ve lived in fairly egalitarian, hunter/gather societies. But we’ve also lived in very hierarchical tyrannies as well. We clearly can manage to exist in both and develop all kinds of different societies. Why hierarchy seems to matter, why status differences matter so much and so the gap between rich and poor matters, is because as human beings, we are very sensitive to social relationship. We have an evolved psychology that makes us very aware about how others judge us.

If you think about it, some of the most difficult things to do, or the most potentially embarrassing situations wherein, those where other people can judge us negatively. Rather like what I’m doing now, which might go out and been seen by hopefully thousands of people and they might think I’m doing a good job, or a bad job, and being aware of that can make us feel very embarrassed, be very aware of how others judge us, and that really affects our psychology and our biology in very profound ways.

So, if we’re looking at societies where the social distances between people are bigger as they are in unequal societies, there’s just more potential for all of us to feel we are judged negatively by others and to feel that our status really matters, that it’s really important.

Question: What is the Social-Evaluative Threat?

Kate Pickett: Social-Evaluative Threat that’s a term psychologist’s use. There are two psychologists who looked at all the studies that other researches have done on what kind of stresses most reliably raise our cortisol levels. What kinds of stress most reliably stress us? And they usually do this kind of work by inviting students into the laboratory and asking them to do unpleasant tasks. The might ask them to solve math problems or to write about an unpleasant experience, or be videotaped doing something. And the question these researchers asked was, which kind of stress most reliably raises our stress hormone levels? And they found it was ones which contained a social-evaluative threat. So, it’s not so much having to do math problems, it’s having to read out your real marks at the end and your scores and share them with other people. It’s tasks in which other people can judge you negatively, that most reliably make you feel stressed.

Question: How does status anxiety link with consumerism?

Kate Pickett: Well, in our modern societies, we don’t really need to consume more stuff for basic survival. We consume, we shop, and we want to earn more money to show our status. And so, owning things that demonstrate that we are keeping up, keeping up appearances that show we are a valued member of society, that’s why we consume so much. In more unequal societies that competition for status is more important. And so, in more unequal societies there is a stronger drive toward status competition and consumerism. All of those things matter more, matters more to earn more money, not because you need more money for basic things, but you need to show your status relative to other people in society.