It's become pretty well accepted that people typically have about 150 friends and acquaintances they interact with on a regular basis. On average, about three to five of these people are our closest friends and family, followed by another ten or so close friends, a few dozen people we interact with frequently and about a hundred acquaintances we check in with every now and then. 

This has been the conventional wisdom since it was first formulated in the 1990s, but new mathematical research suggests our individual friend breakdowns can vary from person to person and at different times in our lives.

"What our theory predicts and what we have now been able to ascertain is that people with a high cognitive capacity could potentially expand their circle of intimate friendships," explains Anxo Sánchez, a professor at Carlos III University of Madrid and co-author of a new study published in Proceedings of the National Academy of Sciences.

This doesn't mean that we can all live a life surrounded by 150 very close friends supporting us at every turn. There's still a ceiling on the total amount of energy that goes in to forging and maintaining friendships and other contacts. So having, say, eight very close friends instead of four probably means you have less time for second or third-tier friends.

The theory also works in reverse. Perhaps 150 friends seems like a ridiculously small number of people. We probably all know of someone who has spent tons of time online cultivating a large network on social networking platforms. Odds are that all that digital friending came at the expense of more intimate relationships. 

"It is impossible to have relationships with 150 people and for them all to be intimate," explains co-author Ignacio Tamarit. "If one has a large number of relationships, it must mean that they are almost all superficial."

The researchers predicted this effect using a mathematical theory and then found that it held true in actual data gathered on the personal networks of isolated immigrant communities in Spain. 

The same effect can also be found in small communities where are simply fewer options for people to interact with. This is a notion the researchers point out that I can vouch for from personal experience.

Some of the most intense friendships I've had to date were during the few years that I lived in an isolated village in rural Alaska. I doubt that I was interacting with over 100 people on a regular basis, but there were at least ten people there that were like family to me at the time. That's probably double what that number has been at any other time in my life. 

You could probably extrapolate this effect out to relationships within large or small companies for those of us whose social lives largely overlap with our careers. For example, people working in small startups might have a larger number of intense relationships than those in the wider corporate world. 

But the bottom line here is that having more close relationships in your life should be possible at any time, but it's going to mean putting in the work, which will probably come at the expense of losing some less intimate relationships. But do you really know half your followers on Instagram, anyway?