What is... | August 22, 2018

What is inequity aversion?

Monkeys don’t like getting less of something good than their friends – and neither do humans. But we also don’t like getting more.


When we like something, we usually want more of it. A larger dessert, a salary increase and longer holidays wouldn’t go amiss.

But there is actually more at play when it comes to whether we feel happy with our lot. Not everyone is satisfied having more than others and those concerned about fairness can refuse to accept more.

Rejection of a larger share of the pie stems from what is known as inequity or inequality aversion. This refers to our preference for an equal distribution between ourselves and others.

Unequal distribution can go two ways, either benefiting or disadvantaging us compared to others, although in many cases our reaction may be the same, and quite intriguing.

Short end of the stick
There is something innate and rather natural about our disappointment when someone else gets more.

Unfairness often rubs us the wrong way when it disadvantages us and we learn how to spot this from a very young age. This is known as disadvantageous inequity aversion.

It isn’t restricted to humans – it’s seen in monkeys and dogs, too.

One study carried out a test where they provided monkeys with either a cucumber or grapes, the much preferred snack, and saw that monkeys who received the cucumber while their friends received the grape hated the unfairness.

In fact, they would throw their own food out of their cage in disgust. 

The longer end
But when inequity aversion goes the other way, things get particularly interesting. Sometimes receiving more than others can cause us to reject an offer – this is known as advantageous inequity aversion.

When this happens, the absolute benefit, or total amount we receive, seems to matter less than how much we get in comparison to someone else.

This isn’t necessarily because we care about other people. In many of the studies that have looked into inequity aversion, neither person receives anything at all if the person who has been offered a greater amount decides that they don’t want it.

In this case, rejection doesn’t result in equal distribution, even though arguably both could be better off if the offer was accepted and each got at least something, even if it was unequally distributed.

This doesn’t happen in monkeys, but it does in humans and it appears to develop as we grow older as it isn’t generally seen before the age of eight.

Contrary to disadvantageous inequity aversion, which is innate, we learn advantageous inequity aversion through some form of socialisation. 

Because of this, it’s expected that maintaining social status is one of the underlying motivations behind it. Rejections aren’t necessarily about right or wrong, but about the question “how do I come off in this scenario?”

It’s also present in varying degrees in different countries and cultures. For cultures that strongly value an even sharing of resources, the only acceptable distribution is an equitable one.

Interestingly, some suggest that this is more prevalent in western societies where equity and fairness are valued as goods in their own right. Advantageous inequity aversion might thrive in certain social environments, but not so much in others.

In real life
It can be uncomfortable if others know we have more than them, but in the same vein, it can feel unfair to have less.

Whether it’s candy, money or something else, the social environment in which it is distributed can affect how we feel, and can make us more likely to opt for an equal outcome. Even if that means we end up being worse off sometimes.

BehaviourSociety

eZonomics team
.(JavaScript must be enabled to view this email address)