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Enemy me on Facebook

In a friend-obsessed world, research is uncovering real benefits to having a nemesis

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No one wants an enemy. Few things could be more stressful and potentially damaging: We dread the nemesis vying for the same job, a rival business trying to steal customers, or the opposing sports team that always sweeps.

A half-century ago, however, a British ornithologist put forth a surprising new idea about enemies in the natural world: Maybe they aren’t always such a bad thing. In a 1954 book chapter, James Fisher suggested that territorial birds might actually gain some advantages from living near threatening rivals. He called it the “dear enemy” phenomenon: Birds that compete with their neighbors would also be bound to them in helpful ways.


Over time, the notion of the dear enemy developed and spread. Naturalists observing birds found that multiple species reserved their fiercest aggression not for next-door rivals, but for strangers. Birds that were enemies in the most obvious sense, neighbors competing directly for territory, seemed to fight less, maintaining a kind of détente with their known rivals. Biologists began to study the effect in other animals, from crabs to beavers. Today, there are dozens of studies that examine what happens when animals keep their enemies close.

In a world obsessed with friends, where we cultivate networks of allies and log on to social websites to be “liked” as much as possible, enemies have practically fallen off the radar. We flaunt hundreds of pals, collect and display every casual acquaintance, but we have to stalk our rivals in private. You can’t “enemy” someone on Facebook.

But having a nemesis is in many ways as intense and personal a relationship as having a friend, and studies in the animal world and the human one are revealing that those relationships matter, too. For animals, dear enemies may allow individuals to spend less time and energy fighting with foes; for humans, direct personal rivals appear to help people push their performance. A small number of researchers are exploring how these relationships affect our motivation and success — and although “enemy studies” isn’t likely to ever become its own discipline, their findings provide a different and perhaps more realistic way to think about how competition works.


Of course, there’s also a downside to having an enemy, beyond the fact that someone’s out there plotting your undoing. Biologists have found that the dear enemy effect is far from a natural law — sometimes, “nasty neighbors” really do fight the hardest. And in more controlled rivalries, like sports and business, studies have found that rivals may end up focusing on the wrong goals, or be tempted to cheat. In human relationships, too, there is a hint of the complicated “mutual stimulation” that Fisher hypothesized among birds half a century ago — the kind of relationship that can be both irresistible and treacherous. Enemies, in other words, with benefits.


IN THE ANIMAL world, you can’t ask your test subjects about their longstanding feuds, but researchers can examine how territorial animals defend their turf. Starting in 2008, scientists at the San Diego Zoo Institute for Conservation Research donned head lamps and night-vision goggles and watched for the flicker of skirmishes. Their subject was a solitary rodent about the size of a potato, the Stephens’ kangaroo rat, which aggressively fends off intruders and drums the ground to let its presence be known. Past efforts to relocate endangered kangaroo rats had failed, and this time the scientists were testing the possibility that even for these loners, a dear enemy effect might improve their chances. They relocated some of the animals in groups, alongside the known neighbors they had already negotiated rivalries with, and some at random. What they found was striking: Those that were settled with their previous “enemies” — neighbors they had previously fended off — were more likely to live, had 24 times as many babies, and spent less time fighting and more time gathering food and digging burrows.


“The idea is it’s better to know — even if you don’t like them, a known neighbor is better than an unknown stranger,” said Debra Shier, a scientist at the San Diego Zoo.

The dear enemy phenomenon doesn’t always prevail: As a young scientist, Ethan Temeles, now a biology professor at Amherst College, watched Northern harrier hawks feud viciously with their neighbors while fighting less aggressively with wandering “floaters” — nonterritorial strangers — and theorized that the dear enemy phenomenon depended on what was at stake. For hawks competing for food, a neighbor might be a real enemy and a threat to survival, but if food is plentiful, neighbors might be “dear,” posing less of a threat than random drifters.

Temeles wrote a paper about his findings shortly after a particularly arresting unneighborly event was transpiring in the Middle East: Saddam Hussein’s invasion of Kuwait. Though he says he tries to avoid projecting his work onto human culture, Temeles sometimes thinks about how the dear enemy effect might fuel world affairs. Both the formation of the European Union and China’s purchasing of agricultural lands in other countries, for example, could be seen as mutually beneficial relationships tinged with rivalry. “Certainly I think there are human parallels,” Temeles said.


What those parallels are, though, is not an easy question to answer. In a laboratory setting, it’s difficult to conjure enmity — that combination of history, evenly matched performance, and overlapping goals that keep rivals forever nipping at each other’s heels.

But there’s one arena where people do have clearly defined nemeses, and a way to measure results: sports. Anecdotally, sports rivalries are some of the greatest dear enemy stories ever. Who doesn’t believe the Red Sox play differently against the Yankees, or BU against BC in hockey? In the 1980s, the heart of the epic Celtics-Lakers basketball rivalry was a personal competition between two of the best players in the history of the sport. Larry Bird, the Boston Celtic, said he would search the box scores for one thing each morning — how Magic Johnson of the Los Angeles Lakers played the night before. Johnson, for his part, said that he always circled the Boston games on the schedule when it came out.

“To me it was the Two and the other 80,” Johnson said in an interview with Sports Illustrated in 1992.

Do such intense personal rivalries have measurable effects? When Gavin Kilduff, an assistant professor at the New York University Stern School of Business, began looking into rivalry in 2006 he found that the question had been largely ignored in the research world. Competition was well studied, but cubicle-based experiments were often a poor approximation of how people vie against each other in real life.


So Kilduff looked for real world settings where existing rivalries could be tracked and quantified. In one study presented at the annual meeting of the Academy of Management last summer, Kilduff tracked the members of a running club who frequently competed in road races. He found that more than half of the runners said they felt rivalry toward at least one other competitor, with the average number of rivals at about three people.

Then, analyzing three years of race data, he objectively identified rivals, by finding which runners frequently competed, finished close together, and shared certain basic demographic similarities. Then he analyzed an additional three years of data — including 1,263 road races for 82 runners. When runners raced against one or more rivals, he found, they sped up — increasing their average speed by five seconds per kilometer. They got a clear performance benefit.

In a 2010 study published in the Academy of Management Journal, Kilduff turned to college basketball. He surveyed 421 sportswriters and rated the level of rivalry between 73 universities that had Division 1 men’s basketball teams. He found that when rivals played one another, there were more blocked shots and increased defensive efficiency. Defense, he said, is generally thought to respond to motivation, whereas offensive precision — shooting and passing accuracy — is not. This supported the idea that in tasks where effort can make the difference, rivals could provide motivation and a boost in performance. And a 2003 study by other researchers published in the journal Physiology and Behavior similarly found hints of rivalry’s importance: If a team was perceived as an “extreme” rival, the testosterone levels of male soccer players surged higher than when they faced moderate rivals.


IN THE HISTORY and mythos of human achievement, certainly, rivalry is a crucial plot component. The grand scientific challenge to read the 6 billion letters of DNA that make up a human being took on drama when it was cast as no longer just a massive project, but a high-stakes race between two rival teams. Last year’s Nobel Prize in physics was split between members of two rival teams, who had raced to measure what they thought would be the slowing of the universe’s expansion. Their rivalry not only spurred them to work faster, but also gave each team confidence that the results — which ran counter to all expectations, and changed our view of the universe — could be correct.

“There was a little bit of an element of competition — let’s not get left behind, let’s hurry up . . . .They were putting up noise they were getting the same result, and that really raised the excitement level for all of us,” said Adam Riess, a Johns Hopkins University astrophysicist who shared the physics Nobel, at a press conference the day he was awarded the prize.

But just as nasty neighbors offer a counterpoint to the dear enemy phenomenon, having a human nemesis can have downsides. Kilduff has become interested in the negative effects of rivalry, which can spur unethical behavior that may far outweigh its motivational benefits.

In a study presented in 2010, he analyzed the performance of professional soccer teams in Italy, where grandiose rivalries unfold and dirty tactics are tallied. He tracked the frequency of yellow and red cards thrown out at games, used to flag rules violations or unsportsmanlike behavior. When teams with rivalries were playing each other, yellow and red cards were far more frequent.

It’s not just unethical behavior, either. Concentrating too much on a foe may divert effort to the wrong goal — for example, being driven by the heat of competition to pay too much, a phenomenon know as “competitive arousal.”

So if the right kind of rivalry can boost our game, but the wrong kind might push us to cheat or overspend, how can we use this information? It’s tricky — sports rivalries aside, nobody wants to conjure enmity simply to coax people to work harder. Clearly, competition — what triggers it, what sends it off the rails, and how to structure it — is important to get right.

In an attempt to figure out what kind of competition is optimal, researchers are trying to break it down to its elements. Stephen Garcia, a psychology professor at the University of Michigan, has described the “N-effect,” in which the number of competitors can alter people’s motivation and performance. Jennifer Brown, at the Kellogg School of Management at Northwestern University, has described a superstar effect, a decrease in golf performance among competitors when a superstar such as Tiger Woods plays well. The true benefits of studying enmity may be to expose how rivals drive us and provoke us — and the point where the healthy benefits of competition stop.

Paul Diehl, a professor of political science at the University of Illinois, has been studying rivalries in armed conflict between countries, amassing a dataset of about 300 rivalries spanning two centuries. He is using statistics to uncover patterns — what conditions allow rivalries to thrive, how signing treaties affects rivalries, what causes enemies to become friendly. He hasn’t yet found analogies to the laws of physics to describe how animosity develops and escalates, but his hopes for the work give a sense of what’s at stake.

“What we’re looking for is trying to understand the factors that lead to the onset, escalation, and termination of rivalries,” he says. “Even if you’ve got rivalry, you don’t want a war.”

Carolyn Y. Johnson can be reached at Follow her on Twitter @carolynyjohnson.