n a memorable episode of Curb Your Enthusiasm, the curmudgeonly protagonist Larry David is angered by the lukewarm lattes at his local café so he opens a “spite” café. It is an identical coffee shop and right next door, but everything is cheaper. He runs it at a personal financial loss, but is driven by the thought of putting his neighbour out of business. It is magnificently mean-spirited, petty, spiteful – and humorous. A murkier question is can spite be good? It seems counterintuitive to put an optimistic spin on behaviour that, by definition, involves hurting others while incurring harm to yourself. But a new book by Simon McCarthy-Jones explores its benefits. “Spite came from the darkness… It seeks to harm the other and to bring about changes in dominance. Yet it can help us into the light,” writes McCarthy-Jones, an associate professor in clinical psychology and neuropsychology at Trinity College in Dublin. “Spite is a sword of Damocles dangling over our interactions. It has made society fairer and more co-operative.” Yes, you read that right and no, McCarthy-Jones is not a cowboy: psychologists and evolutionary theorists agree that there can be positives to spite. It may help enforce social norms and drive protest movements. And, as McCarthy-Jones suggests, it can lead to greater fairness, while forcing us to consider what fairness even means. Before you start plotting against niggling neighbours, engaging in petty point scoring against your co-worker, or taking your sweet time to reverse from your parking spot because there’s another driver waiting to slide in, this is not a permission slip. Yet it’s worth considering the full spectrum of human behaviour, not just the sunny side. Positive psychology, which has gained momentum since the 1990s, and the wellness movement that has careered through the public consciousness for the past decade, promote niceness and self-optimisation as twinned ultimate pursuits. Spite stands in opposition, because it is about harming others and it harms the doer. It is both anti-social and anti-self. Nonetheless, it is part of us today, thanks to the internet, social media and group-identity politics. So let’s lift this shady quality out of the shadows. “I don’t think there’s a gene for spitefulness,” says David Marcus, a psychology professor at Washington State University and a trailblazer in the study of spite. “But there are core personality traits with a fairly high genetic loading.” These include antagonism (aggression towards others) and callousness (lack of empathy), key components in spitefulness and other related antisocial traits, including sadism and psychopathy. Remarkably, spite was neglected by psychologists until 2014, when Marcus and his colleagues developed a 17-point spitefulness scale in a study that sparked broader interest in the behaviour. Like other traits, he says, whether an individual is spiteful comes down to a combination of nature and nurture. Yet there are patterns. We hit peak spitefulness in our late teens (as many a parent can surely attest) and become nicer with age. And men tend to be more spiteful than women. ​Do we all have a bit of spite within us? Marcus says “probably”, although of course some individuals will be much higher on the continuum. If you use self-completed questionnaires, around 5-10% of the population are spiteful (go figure: no one’s admitting to being nasty on a form). But if you get people to play an auction-based game where they have the chance to spite others, McCarthy-Jones says “around a third display no spite, a third are as spiteful as they can be, and everyone else is in the middle.” Although the study of spite in psychology is fairly new, the trait is not. Some believe the phrase “cutting off your nose to spite your face” arose in the 9th century when Scottish nuns, fearing invasion from Norse Vikings, hacked off their noses in order to make themselves unattractive and deter the Vikings from raping them. An old Eastern European folk tale puts spite into even sharper focus: when a genie says it will grant a man a wish as long as his hated neighbour gets double the prize, the man replies: “Put out one of my eyes.” While there’s no evidence to suggest we are more, or less, spiteful than our ancestors, modern innovations have created an environment conducive to spiteful behaviour. By facilitating anonymity, the internet allows spite to thrive, says Rory Smead, associate professor of philosophy at Massachusetts’s Northeastern University and a leading voice on the evolution of the behaviour. “If I can get away with no one knowing [it was me], then the cost is relatively minimal to me, it’s just time and effort,” he says. The internet troll, spitting bile while remaining faceless, is 21st century spite exemplified. By promoting echo chambers, the internet and social media have also helped to accentuate identity politics, another hotbed for spitefulness. The growing gulf between conservatives and liberals, from the UK to the US to France, has meant certain decisions are justified purely because they hurt the opposition (see the now-common motivational phrase “owning the libs”). And McCarthy-Jones suggests that, for many Americans in the 2016 election, a vote for Donald Trump was more than anything a vote to punish Hillary Clinton. What about Brexit? Certainly, a proportion of Leave votes were inspired by a desire to stick it to the EU or to Remainers, knowing it would leave the UK economy devastated. Although there are instances of spite inspiring individual greatness (Ferruccio Lamborghini’s initial motivation for creating his sports car was to one-up Enzo Ferrari), its broader societal benefits are far more compelling. Marcus gives the deliciously petty example of a former colleague of his, a university professor, who wangled his own parking-ticket-book and spent hours writing fines for illegally parked students. “That’s a complete waste of his time; there’s no [personal] benefit to him doing that,” says Marcus. “On the other hand it enforced parking rules, which is not so bad.” In a similar vein are legal cases in which individuals doggedly pursue a debt that’s owed to them; the lawyers’ fees far outweigh the debt, yet they persist on principle. In doing so, rules are upheld and people are made accountable. ​McCarthy-Jones says protest movements are potentially spiteful because there’s a risk to participants’ livelihood. He cites the current protests in Belarus. “One of the few ways regime change may occur is if the workers are prepared to strike and pay a personal cost to economically harm Lukashenko’s regime. They would need to be willing to spite Lukashenko.” He adds that, while spite comes in many forms, “it needs to be partly reclaimed from its negative connotations, especially when it’s used for counter-dominant reasons.” ​When it comes to spite promoting fairness, scientists look to game theory. In the ultimatum game, player 1 is given £10 to split with player 2. They can split it however they like but if player 2 rejects the offer, both get nothing. Research shows that if a low amount is offered, player 2 will reject it on the basis it’s one-sided (this rejection is spiteful insofar as player 2 is sacrificing whatever small sum they were offered). The most common outcome is that player 1 offers a reasonably fair amount for fear of rejection by a spiteful counterpart. This suggests, disarmingly, that you act more fairly towards someone you believe to be spiteful. “The common idea of fairness is that it’s an extension of our pro-social and co-operative behaviours,” says Smead. “But when you consider game theoretic situations, you see that fairness can be interpreted as not necessarily an extension of our pro-social behaviours, but rather a reaction to others’ anti-social behaviours.” In an ideal world we would all cooperate out of pure altruism, in the way the wellness movement advocates. But most of us have a measure of spitefulness (and other dark traits) inside us and, occasionally, it can lead to good things. Obviously we’re not all about to go out and spite each other – God forbid – yet being reminded of the full range of our personalities provides a timely dose of realism. If nothing else, it’s a healthy counterpoint to the perfect yet unrealistic sheen of niceness. Spite: And the Upside of Your Dark Side by Simon McCarthy-Jones (Oneworld Publications, £16.99), is available from guardianbookshop.com for £14.78