Your Brain On... Friendship

Ayesha Sherzai (0:00)

45,000 years ago, someone broke their thigh bone, a femur to be specific, which is the largest bone in the human body. In almost every species on earth, that injury is a death sentence. You can't run, you can't hide, you can't hunt, you can't flee. You are at the mercy of nature. But this particular bone recovered by anthropologists had healed, which means that for weeks, maybe for months, someone else carried food and water for that person. Someone actually protected them, and that instinct never left us. Our brain still runs on it. When you feel connected, your brain rewards you. Dopamine, serotonin, the whole signaling cascade that says, this is good, come back and do this again. But when you're cut off, it does the complete opposite. It sounds an alarm. Your stress hormone and certain chemicals rise. Inflammation climbs. The body behaves as though something has gone wrong because evolutionarily, it has. Dean used to say in his talks, rejection hurts because it used to kill. And that's not a metaphor. That circuitry is real and it is ancient, which raises the question this whole episode is about. We have built a world with more connection points than any humans in history.

Thousands of followers, endless feeds, a phone full of contacts. But we're lonelier than ever. So what is the difference between being in contact and being connected? And what is that gap doing to the brain? To help us think about that, we sat down with Dr. Ben Rein, a neuroscientist and one of the clearest science communicators working today, and the author of a beautiful book on exactly this. This is Your Brain On Friendship.

I love this topic.

Dean Sherzai (1:50)

It's an incredibly important topic. This is not unique to humans, but some aspects of it are absolutely singular and unique for humans. And in many ways, it's what defines humans and defines the point at which we became different, or at least historically and anthropologically, there was a point that the scientist, the anthropologist Margaret Mead said, at this point, we realized that human civilization started.

Ayesha Sherzai (2:20)

She found something as an anthropologist that was fascinating. Can you walk us through that story of what she found and how that changed the definition?

Dean Sherzai (2:30)

Yeah, I believe it was in the mountains of what is considered now the Iraqi Kurdistan. And in that region, probably quite treacherous and quite difficult to traverse, they found a grave site. And in that grave site, there was the bones of an older man with healed thigh bone.

Ayesha Sherzai (2:49)

How old was that body?

Dean Sherzai (2:51)

45,000 years ago. The unique aspect of it was that the heel bone or the thigh bone had healed. For any other species, that being would be dead. There are some exceptions to this, but in general, that's not what you see. And this person didn't just have this healed thigh bone. This person was supposedly deaf as well with hearing issues, as well as eye issues and skull injuries. This person had a lot of problems. For a person 45,000 years ago, how was this person able to survive? The only way that it could have survived was if others took care of it. This is the first time that we could connect humanity with each other beyond survival, beyond need. Because I don't think that they would have needed this person that was already injured and was older. It was an emotional connection or a friendship. It was not a survival gesture. This was one of the first times that we have evidence for this kind of unique relationship.

Ayesha Sherzai (3:46)

So there must have been some benefit that the caregiver or the caretaker was experiencing, whether that's a biological pleasure of your brain creating all these neurotransmitters like dopamine or serotonin when you take care of someone else, or it could be a more social benefit. What is it? Is it in the brain and in our biology? Or was it more of a transactional thing or maybe a combination of both?

Dean Sherzai (4:15)

I think it's a combination of both and there's some evidence of that being a combination of both. There has to be some transaction. There has to be some benefit. And the benefit is what we carry beyond the physical things that we carry. Human beings started to carry stories. The learning that we had gained from another being that had lived 20, 30, 40, 50 years, 50 years was a lot back then, remember, was not just entertainment, but it carried information that could be transmitted. These forms of oral transmission of information probably was more powerful than any kind of rock weapon or tools that you would carry, because that information could be carried to a lot of the members of the family and told over and over again. So this being, besides the fact that had an emotional connection with you, that made you feel good about that connection through your stories, your shared love, your shared experiences, also most likely carried stories of the community that then imparted an incredible new type of power to this community. The human story was the new weapon. The human story was what actually propelled humanity way beyond other primates. One of the theories, the reason we invested in our elders, was definitely an emotional connection, but more importantly, the fact that as they got older, they also carried the most important aspect of the community, which was their culture, their stories, their traditions, their rituals, that gave them value, because now their consciousness was at a level that they could actually have a value for themselves and the group. And this being that was older than the rest of them could impart this to the rest of this community. Imagine what that does. That creates cohesion. That creates connectivity. That creates the thing that makes them more powerful. There should be a movie made about this. I don't know how you can make a Hollywood movie about Neanderthals, but the underlying concept is so beautiful that the moment or at the time that human beings realized that those stories are all that makes them who they are. With that came investment in our elders, investment in our friends, investment in our partners, beyond the usual connections that usually connect sentient beings. I think it's the most romantic, the most meaningful story we have.