Recently, while finishing up delivering a talk in Silicon Valley, I found myself struck by a deep sense of dread. I hadn't brought enough copies of hand out materials for the unexpectedly large group. This meant that at any moment a small mob of otherwise friendly people might turn against me, driven to expressing mild rage from a sense of unfairness. It was enough to put me on edge for some time until I labeled what was going on.
Fairness is the fifth and final domain of threat or reward I have written up in a series of posts, the others being Status, Certainty, Autonomy and Relatedness. These five ideas together make up the 'SCARF' model that has become a popular way of thinking about what happens in the brain during social situations. In later posts I will go further into the implications of the whole model, and how it relates to management, creating change, bringing up kids and other issues.
Fairness is a primary reward or threat
The fact that being treated unfairly can generate a strong threat response is unlikely to be a surprise to anyone. However what may be a surprise is that a sense of fairness can also be rewarding, in and of itself, and significantly so. Fairness, it turns out, is another primary threat or reward: the experience activates the same network that monitors real pain and pleasure.
Prime your brain to look out for fairness issues and they start to appear everywhere. Political clashes, both verbal and violent, tend to be driven by fairness issues. I recently turned on the television to see a villager in Africa shouting that she was willing to die to right the injustice of an unfairly rigged election. Fairness-generated emotions can run high in more mundane situations too: the feeling of being "taken advantage of" by a taxi driver taking a longer route can wreck an otherwise great day, despite the relatively insignificant money involved. It's the principle that counts. The legal system is deeply about fairness. Think of people who spend enormous sums of money to "right wrongs" 
in court, with no obvious economic win other than "justice". (In the UK the department that looks after the courts is called the ‘Ministry of Justice'. It could be called the ‘Ministry of Fairness' in some ways.) We crave fairness, and some people risk their life savings and even their lives to get it.
Fairness can be more rewarding than money
Golnaz Tabibnia, an assistant professor at Carnegie Mellon University, studies fairness and the way people make judgments about it. "The tendency to prefer equity and resist unfair outcomes is deeply rooted in people," Tabibnia explains. One of Tabibnia's studies, in collaboration with Matt Lieberman, uses an exercise called the "Ultimatum Game." In the Ultimatum Game, there are two people, who receive a pot of money to split between themselves and the other person. One person makes a proposal and the other person has to decide whether to accept the proposal or not. If they don't accept the proposal, neither of them gets a reward. "'Inequity aversion' is so strong", Tabibnia explains, "that people are willing to sacrifice personal gain in order to prevent another person from receiving an inequitably better outcome."
Surprisingly, when people receive five dollars out of ten dollars, their reward center lights up more than when they receive, say, five dollars out of twenty. ‘In other words, the reward circuitry is activated more when an offer is fair than when it's unfair, even when there is no additional money to be gained,' Tabibnia explains. Fairness, it seems, can be more important than money.
Fairness doesn't intuitively feel like it is of the same importance as say food or sex. Because of this, many people don't tend to value fairness highly enough, and can be blindsided by the intensity of a fairness response. This is another example of Maslow perhaps being wrong. Society values survival needs such as food, well before social issues like fairness. As a result, someone planning a day-long team meeting might pay attention to ensuring everyone has a good lunch break, but forget all about people's perception of fairness around how the day is organized. More and more research points to the idea that distractions from a sense of unfairness could be harder to handle than an empty stomach.
Fair play
Neuroscientist Stephen Pinker has a theory about where this intense response to fairness comes from, outlined in his book How the Mind Works. Pinker thinks that the fairness response has emerged as a by-product of the need to trade efficiently. In your evolutionary past, when you couldn't store food in the refrigerator, the best place to store resources would have been by giving "favors" to others. Resources were stored in other people's brains, as potential reciprocal snacks down the road. This mental exchange was especially important in hunter-gatherer days, when protein sources arrived intermittently: a bison felled by one person would be too much meat just for his family. To be good at this kind of trading you need the ability to detect "cheaters," people who promise but don't deliver. In this way, people with strong fairness-detectors would have evolutionary advantages.
These days, with fridges and bank accounts, you don't need to trust other people in such a primal way. Your fairness detecting circuits are still there, but now they tend to get more of a work out in the form of leisure activities, such as the game of "cheat" played by kids, or Texas Hold-Em poker, played by millions of adults the world over. These games provide an opportunity to flex your cheating and cheater-detecting muscles. While fairness in real life can generate a threat or a reward, detecting unfairness can be fun for the whole family.
When it's just not fair
Perceiving unfairness generates intense arousal of the limbic system, with all the attendant challenges this brings. As one example, because of the generalizing effect, accidental connections become easier: if you think one person is being unfair, everyone else may seem to be acting unfairly too. Many arguments between people, especially those close to us, involve incorrect perceptions of unfairness, triggering events that activate an even deeper sense of unfairness in all parties. This often starts by someone misreading one person's intent, being slightly mind-blind for a moment. The result can be an intense downward spiral, driven by accidental connections and one's expectations then altering perception.
Since unfairness packs a hefty punch, it's easy to get upset by small injustices when you're tired, or when your limbic system already has a strong base load of arousal. One study showed that the amount of seratonin in the blood, which is involved in feeling content, determined how people reacted to unfair situations. When you feel low contentment, you can have a strong response to unfairness. You have to be extra careful in these situations. If you are kept awake by young children, it's easy to get cranky with a partner asking you for help. If you've had a big day at the office, it's easier to get unnecessarily annoyed with a supplier who you think might be ripping you off, even though it might only be for pennies.
