The Mystery of How Our Brains Work Together

A The brain has long been a source of fascination and scientific interest, from the philosophers of Ancient Greece onwards. In modern times, the mid-twentieth century emergence of the multidisciplinary science known as neuroscience, which combines elements of physiology, biology, computer science and mathematical modelling. This discipline has a variety of aims, all related to the properties of neurons and neural circuits in the brain.  Advances in technology have allowed researchers to carry out studies that delineate the complex neural machinery that enables the individual to make sense of sights and sounds, process language and derive meaning from experience. The vast majority of these studies consist of just three elements: the subject under study, a cognitive task for the subject, and a high-tech machine to see into the subject’s brain.  

B However, a key element seems to be missing. What about other people? We humans are innately social yet neuroscience has focused on the individual. Over the past thirty years or so, this has led to the rise of a new scientific discipline: social neuroscience. The goal of this field is to understand the brain mechanisms that control how people interact and communicate. In other words, how is the brain able to look at a situation and rapidly determine what context clues are necessary to decode what someone else is trying to say? For example, imagine that two friends are sitting together and one points to a glass of water, are they saying that they’re thirsty, or asking if the friend is thirsty, or pointing out that the water has been spilled and should be cleaned up? Communication is so complex and context-dependent, that it is astounding that humans can negotiate the meaning of a word or gesture at all.

C Some of the most shocking discoveries in the field have involved the synchrony of people’s brain activity when engaged in social interaction. When scientists scan the brains of people who are all watching the same movie, or listening to the same piece of music, or even working together to solve a puzzle, their brain activity starts to align, meaning their brain wave patterns occur at the same time.  This finding was completely unexpected. It is well known that people in an audience might all feel sad when listening to a sad story or step in unison to the beat of a catchy song, but no one expected that the same parts of people’s brains would be firing at precisely the same time. Now that scientists have all of this evidence about synchronous brain activity, they are debating what exactly it means.

D The nature of the role of synchrony in social interaction is intriguing to researchers in many fields. Beyond scientists, economists, sociologists, anthropologists, and many others are interested in issues related to human conflict and cooperation. Researchers in these disciplines want to learn more about how synchrony of brain activity (or lack thereof) might contribute to the overall functioning of human groups. Does inter-brain synchrony provide insight into why some corporate teams collaborate effectively while others languish, or why some societies are relatively harmonious while others are mired in political and military conflict?

E Recent work in social neuroscience provides an interesting lens with which to view these phenomena. Consider the Prisoner’s Dilemma, a two-person game that is used to model competitive interaction. Here, each player has to decide whether to cooperate with the other person and share a reward, or defect, which means they get a chance to steal the entire reward, or lose it completely. For example, in one real instance of the game from a study, members of each duo had an opportunity to win $100, by “defecting” and competing against their partner in a game or some other predetermined task. If the duo decided to collaborate rather than compete for the winnings, they had a better chance to “win” the game, but each person would only walk away with $50. The study showed that the brains of players who choose to cooperate were in sync, and the brains of players who choose to defect were not. Some argue that when people cooperate, they are focused on the other person. They might ask, “What are they thinking? Can I trust them?” Both people are doing this, so their brains are in sync. Defectors, on the other hand, are focused on themselves, on how to get away with stealing the reward. This game is used for research, but has wide-ranging implications. For one, it offers a partial explanation for the neurological mechanisms behind cooperation. Brains are synced up when people work together and they are mismatched when they are selfish.

F Humans are quite good at interacting with each other, but for the longest time, scientists couldn’t explain why that’s the case. Now with this new data about inter-brain synchrony, some argue that an answer is taking shape. Neuroscience has tended to focus on thinking, memory, and attention in one brain. We know where vision, hearing, and even emotions are processed, but what about social interaction? How does what one can see, hear, and feel work together to help people connect with and understand others? Some feel that social behavior is so deeply hardwired within human brains that they have put forth what is known as the “social brain hypothesis.” This theory suggests that all brain systems, from basic functions like vision and memory all the way up to self-awareness and higher-order cognition, help humans to be social. Individual humans are meant to live in social groups, and their brains are fine-tuned to connect with friends, families, and communities. These results also help explain why social isolation can lead to mental and physical health issues. Though there is still much left to be discovered, it is clear that social interaction is fundamental to human biology and behavior.