It’s your first semester. Campus is crawling with nameless strangers. Totally invisible, you scan the chattering chaos – in a lame attempt to seem undaunted, you gaze down at your smartphone and wonder, “Will anyone like me? Why should I like any of them? How would I even know a real friend if I found one?” According to a recent study, there are three personality traits most likely to bring you and your new pal together: shared taste in music, resonant religious beliefs, and similar ethical views. If a person shares all three traits, you may become best buds forever. If they share none of these, you might want to go back to your smartphone.
The study was conducted by Jaques Launay and Robin Dunbar of the Department of Experimental Psychology at the University of Oxford. Launay does research on the reasons people form friendships and come to trust one another. Dunbar is best known for hitting upon “Dunbar’s number:” a “theoretical cognitive limit to the number of people with whom one can maintain stable social relationships.” The average for any person tallies at around 150. (This upper limit includes a much smaller circle of close confidants, and excludes more distant partnerships and acquaintances.) From the standpoint of evolutionary psychology, this innate social limit reflects the approximate size of tribes one would expect to find in the ancient ancestral environment. Think of Dunbar’s number as a psychological wisdom tooth: after a quarter million years of evolution, the human mind still bears vestiges of our tribal past.
So who are these 150 people, and how did they wind up at your party?
Numerous studies support what everyone already knows: Homo sapiens tends toward homophily. In other words, most people prefer the company of those most like themselves. They are more apt to engage with similar people, tend to forge longer lasting relationships with them, and behave more altruistically toward them. This makes sense from an evolutionary perspective: whether consciously or not, human beings seek out their familiar tribal fellows for safety and support.
What is less understood is whether these birds tend to flock toward certain kinds of feathers more than others – and if so, which ones? Those which indicate wealth and status? Or those signaling commitment and loyalty?
Launay and Dunbar performed two web-based experiments, utilizing samples of 295 and 195 people, respectively. The populations were drawn from across the UK, and roughly approximate that nation’s overall demographics. The experimenters used a within-subject design – meaning that each participant is subjected to the full range of questions and interactions. This design reduces the confounding effects of individual quirks. Participants used their own computers.
First, each person completed a questionnaire designed to gauge a range of traits, including occupation, humor, political leaning, religious beliefs, and musical tastes. Some categories were more probing than others. For instance, the “hobby/interest” options were vague and dull, including “Collectibles,” “Travel,” and “TV/Radio.” On the other hand, the assessment of “ethical views” utilized detailed quandaries involving euthanasia, third-trimester abortion, and protecting a friend by perjury.
Having answered these questions, subjects were then “introduced” to various online partners – who were actually software bots – with whom they performed a cognitive task. In a sneaky bait-and-switch, participants were told this task was the goal of the experiment. Before the task began, the subjects would be instructed to read through their partner’s personality profile. The number of shared traits would vary from partner to partner: e.g., from roughly two thirds, to one third, to none at all. Having completed the cognitive task, the participants would then be given various questions relating to their potential affinity for these strangers.
Basically, the experimenters asked: What are the chances you would hang out with this person in real life?
The participants’ responses were quantified on two scales: likeability and the Inclusion of Self in Other Scale (IOS). The IOS measures subjects’ sense of interpersonal similarity, while likeability looks at their degree of felt affinity. The results show a strong correlation between the two.
Of the fourteen traits tested for in Experiment 1, participants showed a marked preference for shared ethnicity, political views, musical taste, religion, and ethical views. In the second experiment, the questions were narrowed down to the first experiment’s top seven traits. Experiment 2 found that the best predictors for how much a participant would rate a stranger’s likeability were musical taste, religious belief, and ethical statements.
These results suggest that, when dealing with strangers, people seek to harmonize their gods, good deeds, and groovy tunes. Just imagine a long car ride with any of these out of whack.
Launay and Dunbar readily admit that their methodology ignores important factors such as physical appearance and personal charisma. The web-based interaction is more like a shut-in scrolling through “strictly platonic” ads on Craigslist than random strangers mixing at a pub. However, given the increasing reliance upon social media, such online experiments may actually be more relevant to friendships of the future.
It may seem arbitrary that people would choose potential friends based on musical taste, religion, and ethical views, but these three categories flow into each other in intricate ways. Religion is at the intersection. Anyone who’s felt a choir’s rousing crescendo surge through a congregation may suspect that aesthetics and religiosity share a common source. At the other end, a person’s idea of ultimate reality informs critical ethical decisions, such as whether to assist in the death of a terminally ill loved one, or to hold on in Jesus’s name.
It is worth noting that 32% of the present study’s participants claimed to be either “agnostic” or “atheist.” This is in line with the ongoing process of secularization in many European nations, but may also obscure something deeper. Even as secular culture sheds traditional religion, one frequently finds an outpouring of alternative spiritual values and social norms beneath its canopy.
Most importantly, there are communal aspects of music, religion, and ethical norms that create and cement social bonds. This holds true across cultures, from Lakota Sioux war dances to psychedelic rock to the Catholic Mass. It is hardly surprising that people would gravitate toward similarities in these three traits. Each one is a strong signal of tribal membership. If Dunbar’s number is accurate, the old saying is true: you can’t be friends with everyone. With limited slots on your guest list, it’s best to be selective.
For more, read “Playing with Strangers: Which Shared Traits Attract Us Most to New People? “ in PLOS ONE.