Science Says You Can Really Only Have 5 Close Friends At A Time

Someone better alert Taylor Swift's squad.
Danny Moloshok / Reuters

According to new research, we may really play favorites when it comes to our BFFs -- at least unknowingly. Apparently, our capacity for simultaneous close friendships peaks at approximately five people.

A recent analysis of cell phone records may corroborate a long-standing anthropology theory that our brains may limit the number of people who can play a meaningful role in our lives, as reported by the Massachusetts Institute of Technology’s Technology Review.

In the '90s, British anthropologist and researcher Robin Dunbar observed a correlation between brain size and social relationships. The research suggested that the bigger an animal's brain, the larger that animal's social group. Dunbar developed a formula to figure out an approximate figure based on brain size.

He then applied his findings to the size of a human's brain and determined we are only capable of having a finite number of people in our social sphere -- 150 to be exact -- due to the size of our brains.

Dunbar further studied this concept by looking into the emotional depth of those relationships. Each of the 150 people in our social network is "layered" based on the level of closeness we feel to that person. The closest emotional layer -- the one we consider to hold the most meaning and connection -- contains approximately five individuals, according to Dunbar.

The second layer of closeness includes an additional 10 people. The third layer includes an estimated 35 people on top of that. The final layer includes 100 people for a total 150.

Scientists recently applied this theory to the masses and discovered Dunbar's estimate may not be too far off. A team of researchers in the U.K., along with Dunbar, analyzed mobile phone data from 2007 (a time before the widespread use of social media) of 6 billion calls made by 35 million people in Europe. The team looked at individuals who made reciprocated phone calls to approximately 100 people and used the frequency of the phone calls as a measure of closeness. The results are still under peer review, Pádraig Mac Carron, one the study's authors, told The Huffington Post.

The team found that the patterns in the phone calls were incredibly similar to the numbers suggested in Dunbar's original layers. The average cumulative layers in the new study held 4.1, 11.0, 29.8, and 128.9 people, respectively.

"These numbers are a little smaller than the conventional numbers for Dunbar layers, but within their natural range of variation," the researchers wrote in the conclusion.

In other words, individuals called a little over four people the most frequently, on average. The rest of the data somewhat matched up to Dunbar's initial layer numbers (aka people/friends), as well. The middle layers saw the most variability from the original study. This suggests that our brains really do only account for a limited social group, Mac Carron said.

"Most people have a very small number of close friends, but this number varies from person to person," he told HuffPost. The range could fluctuate between one and 15 people, but the average is about four to five, Mac Carron explained.

It's important to note that the research didn't take into account self-reported meaningful friendships, which could have been a useful comparison. It also doesn't identify whether some of the frequently-called individuals were people like family members (although, who says your Mom can't be one of your best friends?).

The observed patterns do, however, offer some fascinating insight into human behavior and social circles. It appears that our strongest relationships -- the ones where we actively keep in touch -- are limited regardless of how we feel about the other people in our lives who we consider close. It suggests that there really is a preferred "squad" that we rely on and apparently it isn't very big.

Apologies to the rest of our besties, though -- you're still great.

This piece has been updated to include comment from the study's researchers and information about the review process of the research.

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