Have you ever wondered why you only tend to have a few besties while other people around you have a whole squad? Well, according to MIT, you’ve got the right idea.

In an article written by the MIT Technology Review, research shows that people create sublayers in their large group of friends, which is why you might be closer to some than you are to others.

That’s because we tend to have no more than five close friends, 10 friends, and 35 people you simply just know or count as acquaintances.

The layers form based on the strength of emotional ties one person has to another, helping to form a friendship that ultimately turns into the difference between someone being a best friend, and someone just being a friend.

Of course these people might change as you get older, move, change jobs and just mature mentally. But no matter where you end up, you will only ever have five people you call your besties at one time.

The study was conducted by Robin Dunbar, a British anthropologist, in 2007. He tested his theory of people creating sublayers in their circle of friends by analyzing 6 billion phone calls made by 35 million people.

He then looked at how often an individual made a call to a specific person, and noticed the average number of relationships closely maintained by a single person was no more than five at a time.

He then looked at the sublayers and the numbers were also consistent. No more than 35 friends, and 129 acquaintances.

Most people tapped out of people they know at 150, but the numbers could be smaller now that we all have cell phones and ditched the land lines.

Mobile phones only capture a portion of someones interaction with a friend, so the layer could have shrunk in size over the years of texting and DMs.

Still, aiming for a squad of 20 or more doesn’t look like it’s in the cards for humans. By nature, we tend to hold five near and dear.