The Science of Friendships

You can’t choose your family, but you can choose your friends. While this saying is quite common, I have questioned how much truth it holds. What makes certain friendships sizzle while others fizzle? According to psychologist Dr. Jack Schafer, the recipe for friendship is pretty simple: Friendship = Proximity + Frequency + Duration + Intensity. Typically, intensity is the factor that we attribute our friendships to: we believe that if we have stimulating conversations, we will develop a close friendship as a result of shared values. In reality, intensity is only a small part of the friendship formula. Take a look at your friendships and you will quickly notice that these factors have played a large role in the formation of your current relationships. Your close friends may be the people who lived on your floor in res (proximity), those you sat beside in class (frequency and duration), or those in your frosh group (intensity). This all makes sense in theory, but how much time do you need to spend with someone to become friends? Professor Jeffrey Hall found that to move from an acquaintance to a casual friend, you must spent 50 hours together, and another 90 hours in order to move from that stage to “friend” status. Forming a close friendship requires an even more significant time investment: at the friend stage, you should expect to spend more than 200 hours together before you can consider someone a close friend. Evidently, friendships are quite time-consuming but undoubtedly worthwhile, as your health and happiness are closely linked to the number and quality of your relationships. This raises the question: how many friends does a person need? In 1992, Robin Dunbar, arguably the most influential person in the field of friendship study, proposed a theory he called Dunbar’s number. His theory suggests that, due to the average size of the human brain, there is a cognitive limit to how many stable relationships we can maintain: 150 casual friends. Ranging on a spectrum from five to 1500, Dunbar posits that the number of social ties people are able to maintain is surprisingly consistent:

five best friends, 50 good friends, 150 casual friends, and 1500 people one could recognize by name. Interestingly, Dunbar’s numbers remain relatively constant but the composition of our friend circle fluctuates. The social networks of young adults can have a yearly turnover rate as high as 40 per cent. Additionally, despite the widespread use of social media and its ability to help us cultivate and maintain friendships, Dunbar’s upper limit still applies. According to Dunbar, Facebook has been so successful because it allows us to keep track of people who would otherwise disappear from our minds. While friendships may develop as a result of seemingly random factors, they still require time and energy to maintain. In fact, investing in friendships is one of the best uses of your time. A 2010 study found that in terms of increasing one’s lifespan, having strong friendships is comparable to quitting smoking and nearly twice as beneficial as regular exercise. So, it’s doctor’s orders: give your friends a call.

by Taylor Ball