A fourteenth-century-bc peace treaty recorded on a cuneiform tablet contains an invocation to Mithra, the Indo-Iranian god of the sun as well as of oaths and mutual obligation. In the Roman Empire, Mithras was honored as the god of loyalty to the emperor, while in Indian Vedic texts, he represents friendship and benevolence and, along with the god Varuna, is entrusted with the maintenance of the gods’ essence.
While walking around New York City, a young Meyer Lansky was stopped by a group of Italian teenagers demanding protection money. Their leader, later known to the public as Lucky Luciano, had been recruited into the Lower East Side’s Five Points Gang at a young age and would go on to develop a national crime syndicate. “Go fuck yourself,” Lansky responded. A lifelong friendship between the two gangsters grew out of this encounter. “They would just look at each other,” recalled Bugsy Siegel. “A few minutes later, one would say what the other was thinking.”
Researchers at Yale and UC San Diego found that among a sample of almost two thousand subjects, none of them related, pairs of friends were significantly more likely to share gene variants than pairs of strangers; on average, close friends were the genetic equivalent of fourth cousins, making them “functional kin.” “Not only do we form ties with people superficially like ourselves,” said sociologist Nicholas Christakis, one of the study’s authors, “we form ties with people who are like us on a deep genetic level.”
According to a study published in the American Sociological Review, from 1985 to 2004 the mean number of “close confidants” (people with whom one can discuss important matters) Americans had dropped by nearly a third, from 2.94 to 2.08 people. Similarly, the number of those who said they could not discuss important matters with anyone more than doubled, to nearly 25 percent. “The general image,” the researchers wrote, “is one of an already densely connected, close, homogeneous set of ties slowly closing in on itself.”
Dale Carnegie’s best-selling How to Win Friends and Influence People originated from a popular nighttime lecture he used to deliver at the YMCA. The book lists six ways to make people like you: be interested in others, smile, remember a person’s name, be a good listener, talk in terms of the other person’s interests, and make the other person feel important. Novelist Sinclair Lewis summed up Carnegie’s advice: “Smile and bob and pretend to be interested in other people’s hobbies precisely so that you may screw things out of them.”
In Confucianism the five cardinal human relationships (wulun) are love between fathers and sons, righteousness between rulers and subjects, difference between husbands and wives, seniority between older and younger brothers, and trust between friends. Though at the bottom of this hierarchy, friendship is the only relationship not determined by ranking or kinship.
In a letter from Deir el-Medina, an Egyptian village of artisans working on pharaonic tombs during the period of the New Kingdom, Nakhtsobk, the self-described “scribe of the necropolis,” complains to Amennakhte, a workman, about being neglected. “It is only to me that you don’t send anything whatsoever, really this is a rotten day,” Nakhtsobk writes. “What offense have I done against you? Aren’t I your old eating companion?” In another letter from the same village, the sender, possibly Nakhtsobk, writes dejectedly, “It is I who write to you continually, but you never write to me.”
Friendship cannot exist “between the well-fed, prosperous / and the lean and down-and-out in the world,” states the Panchatantra, a collection of Indian animal fables from around the third century bc. In one story, when a crow tries to befriend a mole after witnessing his impressive skill in escaping from hunters’ traps, the mole exclaims, “You are the eater; I am the food. What kind of friendship can exist between us?”
Ahead of a visit from Hannah Arendt in 1971, Mary McCarthy purchased anchovy paste, which she knew Arendt enjoyed. When McCarthy pointed out where to find it in her cupboard, Arendt looked displeased. “She had a respect for privacy, separateness,” McCarthy later wrote. “I knew I had done something wrong in my efforts to please. She did not wish to be known, in that curiously finite and, as it were, reductive way. And I had done it to show her I knew her—a sign of love, though not always—thereby proving that in the last analysis I did not know her at all.”
In his Muqaddimah, the fourteenth-century Arab historian Ibn Khaldun describes talismans that make use of “the loving numbers” 220 and 284 to create the perfect union between friends or lovers. Two effigies are created, and the larger number is placed on the effigy of “the person whose friendship is sought.” The result of this “magical operation,” he explains, is a connection between the two such that “one is hardly able to break away from the other.”
Looking at the records of 35,000 Union Army veterans who had served between 1861 and 1865, a 2010 study found that soldiers whose military units lacked a sense of camaraderie were six times more likely to have had heart attacks or strokes by their late fifties or early sixties than counterparts from units with strong esprit de corps. “Somehow being armed with close social bonds in the extremely stressful situation of battlefield combat,” said one of the researchers, “has a protective effect that continues long after the fighting has ended.”
A 2013 study involving American college students found that participants were more likely to deem a face more attractive if it was presented amid a group of faces than if it was displayed alone. This “cheerleader effect,” scientists ventured, was “due to the averaging out of unattractive idiosyncrasies.” Two years later a similar study conducted with Japanese participants failed to replicate the results of the initial study.
At Uyun al-Hammam, an ancient graveyard discovered in northern Jordan, the remains of foxes were found buried alongside human remains, leading to speculation that humans may have kept red foxes as pets around sixteen thousand years ago, several millennia before animals were believed to have been domesticated. At one point, a human corpse had been disinterred and relocated. “Because the link between the fox and the human had been significant,” said one archaeologist studying the site, “the fox was moved as well.”
After the suicide of one of his former patients, Zimbabwe-based psychiatrist Dixon Chibanda began training local grandmothers in evidence-based talk therapy. Since 2006 over four hundred grandmothers have been trained to deliver free services in more than seventy communities across the country while sitting on a “friendship bench” next to a local clinic. Friendship-bench patients were found after six months to have improved more significantly than patients receiving standard care. “I value human beings so much,” said one grandmother in the program. “I introduce myself and I say, ‘What is your problem? Tell me everything, and let me help you with my words.’ ”