The Social Brain by Tracey Camilleri The Psychology of Successful Groups
What's it about?
The Social Brain (2023) investigates how human connection drives team performance, trust, and resilience in modern organizations. Drawing on insights from psychology, anthropology, and organizational design, it offers practical guidance for shaping group dynamics, building strong relationships, and creating environments where people thrive.
When was the last time you felt truly connected at work? Perhaps it was sharing coffee with colleagues during a late-night shift, or finding unexpected common ground with someone from a different department. These moments of connection shape our professional lives in profound ways – influencing everything from our mental health to our creative output.
Research into human relationships reveals striking patterns: like how group size affects our minds, how moving together builds teamwork, and how trust can make or break an organization.
In this lesson, we’ll explore cutting-edge findings on how humans bond and collaborate, offering practical insights for anyone looking to build stronger teams, spark innovation, or foster resilient organizations.
Let’s begin.
How many meaningful relationships can one person maintain? This seemingly simple question has profound implications for how we organize everything from businesses to communities. The answer, it turns out, is surprisingly consistent: about 150 people mark the natural limit of our social world. This cognitive threshold, known as Dunbar's number, was discovered by evolutionary anthropologist Robin Dunbar through decades of research into human social networks. Beyond 150 people, it seems, something fundamental breaks down in human groups.
Dunbar discovered this pattern by studying group sizes across many contexts. These included hunter-gatherer societies, historical villages, military organizations, and even modern corporate structures. The number emerged repeatedly - from the size of English villages listed in 1000 CE to the basic unit size of professional armies throughout history. Even in today's digital age, studies of social media networks show people maintain meaningful interactions with roughly the same number of individuals.
The biological foundation for this limit lies in our brain’s anatomy. Neuroimaging studies reveal that regions like the frontal lobes, temporal lobes, and limbic system – the emotional center of the brain – determine how many social bonds we can maintain. And their capacity is finite. But how does this biological limit play out in real-world settings?
Our social worlds organize themselves in distinct layers, like ripples spreading from a stone dropped in water. At the center lies an intimate circle of about five people - those we trust completely and contact weekly. Beyond them, approximately fifteen people form our sympathy group - those whose death would devastate us. Then comes a layer of fifty - our broader social circle - and finally, that outer ring of 150 meaningful connections.
This layered structure has real implications for organizational design. Small teams of five or fewer members create an environment of intimacy and trust that enables seamless communication and coordination. A study of software development teams revealed that groups of 3-5 members achieved 72% higher productivity than teams of 9 or more, with less communication overhead and decision-making complexity than with larger groups. In the military, special forces units specifically limit team sizes to 4-5 members to ensure the highest levels of trust and efficiency.
Imagine a thriving community suddenly struggling with disputes and dwindling cooperation. This is what happens in Hutterite settlements when their population grows beyond 150 – a vivid example of Dunbar’s number in action.
Members become less willing to contribute to communal efforts, disputes increase, and the sense of shared purpose diminishes. At approximately 167 members, Hutterite communities deliberately split, forming new daughter settlements. Both parent and daughter communities are carefully structured to maintain optimal sizes - around 150 and 50 people respectively – a pattern that has remained remarkably consistent for over 100 years.
For today's organizations, these findings carry profound implications. When groups exceed their natural size limits, productivity and morale suffer. The solution isn't always staying small, but may instead mean organizing in networks of small units. The key is to find ways to preserve intimate working relationships while accommodating necessary growth.
It’s 3 AM, and three railway workers huddle together under dim lights, sharing steaming coffee and swapping stories to keep the cold at bay. Across town, in a sprawling warehouse, a solitary worker follows computerized instructions through an earpiece, passing colleagues like ships in the night. Research in the UK compared these two contrasting work environments. The railway workers, despite harsher conditions, showed significantly better mental health than their warehouse counterparts.
Why? Before we answer, let’s look at another example. Researchers studied heart attack survival rates across 148 studies and 310,000 people. They discovered that the strongest predictor of survival – surpassing traditional factors like diet, exercise, and air quality – was the number and quality of close friendships. Only smoking cessation came close to matching friendship's impact on survival rates. This same principle of connection applies to the workplace, where close bonds can make a surprising difference
These powerful effects stem from what biologists call the "kinship premium" - our innate tendency to help and value those closest to us family members above all others. The human brain processes close relationships through similar neural pathways as family relationships. In workplace settings, this closeness translates into measurable performance gains: Gallup's thirty-year research reveals that 63% of employees who report having a best friend at work demonstrate high engagement, compared to just 23% of those without close workplace bonds.
Microsoft's Work Trend Index reinforces these findings. Employees with strong workplace relationships consistently generate more innovative ideas, demonstrate better strategic thinking, and collaborate more effectively than their isolated counterparts. When the pandemic forced many organizations into remote work, those companies that had cultivated strong social bonds proved more resilient. Their employees maintained productivity and creative output even when physically separated, drawing on established relationships to overcome distance.
In a separate study involving a warehouse, after management redesigned break schedules to allow team members to overlap, employees began spontaneously organizing shared lunch periods. Within six months, cross-team collaboration increased by 27%, and safety incidents dropped by nearly a third - suggesting that when organizations create space for natural human connection, both performance and wellbeing can benefit.
At a corporate gathering, carefully orchestrated groups of four find themselves sharing unexpected common ground. A coder and an accountant discovered their shared passion for Renaissance art, while two managers from different divisions realised they'd grown up in the same small town. These aren’t chance encounters - but the deliberate result of a forward-thinking organisation working to build stronger teams.
Research has identified seven core dimensions that illustrate how people naturally form bonds. These "Seven Pillars of Friendship" are shared dialect, geographical origin, career experiences, hobbies, worldview, sense of humor, and musical tastes. They predict relationship strength with surprising accuracy. When two people share six or more pillars, they typically form close, lasting bonds. Yet innovation often springs from connecting those who share fewer commonalities. The art, then, lies in balancing these forces.
Consider how Gore, the materials science company, structures its 11,000-person organization. Their model pairs each employee with both a formal leader and a "sponsor" - a learning buddy chosen for their complementary perspectives. This approach creates what Gore calls "lattice relationships" - connections that cross-pollinate ideas while maintaining the comfort of close-knit teams.
Other organizations have found creative ways to apply similar principles to foster collaboration and innovation. Some design office spaces with carefully placed coffee stations at intersection points between departments, increasing spontaneous cross-team conversations by 35%.
A global insurance company assembled teams based on the Seven Pillars model. They found that teams composed of members sharing three to four pillars, but differing in others, outperformed both highly similar and highly diverse groups in innovation challenges. They built stronger bonds when they shared just enough common ground to communicate easily, while maintaining enough difference to see problems from multiple angles. Their success stemmed not from maximizing similarities or differences, but from understanding how to leverage both.
When Oxford University researchers conducted a study of rowing crews, they discovered something remarkable about human connection. Athletes rowing in sync with others produced double the endorphins of those rowing alone, despite exerting identical physical effort. This remarkable finding pointed to a deeper truth: our brains are wired to respond powerfully to shared rhythm and coordinated movement.
This mechanism comes from our evolutionary history. Just as primates build trust by grooming each other, humans bond by triggering the brain’s trust-building chemicals. When people move, sing, or even breathe together, their bodies release endorphins. These natural opiates create feelings of trust and wellbeing.
Organizations that understand this principle have found ways to harness its power. In traditional theaters, directors begin new productions by having cast members participate in synchronized games and exercises - not merely to break the ice, but also, it seems, to create the biological conditions for trust. These synchronized activities level status differences and build the foundation for creative risk-taking that great performances require.
Military training provides perhaps the most powerful demonstration of synchronized bonding at work. From countless drills marching in formation, soldiers build trust through coordinated movement and shared rhythm. This deliberately engineered synchrony creates bonds so strong that units can function seamlessly under extreme pressure. As one retired general explains, these bonds become the foundation of operational readiness, and are more crucial than any technical training.
These findings carry profound implications for modern workplaces. When a tech startup introduced daily communal lunches, they weren't just feeding their employees - they were creating opportunities for natural daily synchrony that brought coding specialists and client teams into a shared rhythm. The resulting improvements in collaboration and trust emerged not from formal policies, but from hearts and minds moving in time.
In Amsterdam's diamond district, dealers exchange millions of dollars worth of precious stones on nothing more than a handshake. This centuries-old market exemplifies trust at its purest: a small, interconnected community where one's word truly is their bond. Yet few modern organizations achieve this level of faith, and understanding why reveals crucial insights about human cooperation.
Research shows that trust typically breaks down through predictable mechanisms. Simulations show that trust can break down quickly. Just a few freeriders – people who take without giving back – can cause entire systems to collapse. Indeed, this mirrors observations from the real-world: studies indicate that just 1% of people tell 25% of all lies. A few bad actors, therefore, can poison an entire organization.
When trust erodes, networks fragment in distinctive patterns. During financial crises, banks restrict lending to only their most reliable partners. Similarly, social networks tend to contract into smaller, defensive clusters. Yet a study at Newcastle University revealed how deeply ingrained our trust instincts are: simply posting a picture of watching eyes above a coffee station's honesty box tripled payment compliance, suggesting that even subtle cues of accountability can maintain cooperative behavior.
However, many organizations respond to trust breakdown by implementing rigid controls, assuming workers need constant supervision. This approach often backfires, however. The Harvard Business Review reports that employees at high-trust companies experience 74% less stress, 106% more energy, and 50% higher productivity compared to those at low-trust organizations.
Dutch healthcare company Buurtzorg demonstrates a more effective approach. Founder Jos de Blok recognized that, while administrative tasks could be standardized, patient care demands flexibility. The company organizes nurses in teams of ten, giving them autonomy to make care decisions while maintaining shared records for continuity. By trusting nurses to make decisions, Buurtzorg transformed patient care. One nurse described how this autonomy let her focus fully on her patients, helping them recover in half the time – while cutting costs by a third.
Building organizational trust requires consistent leadership behavior and shared values. But perhaps most importantly, it demands resisting the temptation to micro-manage in response to occasional breaches of trust. As the Buurtzorg case shows, organizations that design their systems around the trustworthy majority rather than the untrustworthy minority often find their faith rewarded with both more solidarity and greater performance.
The main takeaway of this lesson to The Social Brain by Tracey Camilleri, Samantha Rockey, and Robin Dunbar is that human connection forms the bedrock of successful organizations.
From Dunbar's number of 150 meaningful relationships to the power of synchronized activities and the crucial role of trust, our biological wiring for social bonds directly impacts organizational performance.
Remember: small teams foster intimacy, shared experiences build lasting connections, and trust flourishes when we design systems around the majority's goodwill rather than the minority's misconduct. Whether you're leading a team or building a community, prioritize creating spaces for natural human bonds to develop.
The Social Brain (2023) investigates how human connection drives team performance, trust, and resilience in modern organizations. Drawing on insights from psychology, anthropology, and organizational design, it offers practical guidance for shaping group dynamics, building strong relationships, and creating environments where people thrive.
When was the last time you felt truly connected at work? Perhaps it was sharing coffee with colleagues during a late-night shift, or finding unexpected common ground with someone from a different department. These moments of connection shape our professional lives in profound ways – influencing everything from our mental health to our creative output.
Research into human relationships reveals striking patterns: like how group size affects our minds, how moving together builds teamwork, and how trust can make or break an organization.
In this lesson, we’ll explore cutting-edge findings on how humans bond and collaborate, offering practical insights for anyone looking to build stronger teams, spark innovation, or foster resilient organizations.
Let’s begin.
How many meaningful relationships can one person maintain? This seemingly simple question has profound implications for how we organize everything from businesses to communities. The answer, it turns out, is surprisingly consistent: about 150 people mark the natural limit of our social world. This cognitive threshold, known as Dunbar's number, was discovered by evolutionary anthropologist Robin Dunbar through decades of research into human social networks. Beyond 150 people, it seems, something fundamental breaks down in human groups.
Dunbar discovered this pattern by studying group sizes across many contexts. These included hunter-gatherer societies, historical villages, military organizations, and even modern corporate structures. The number emerged repeatedly - from the size of English villages listed in 1000 CE to the basic unit size of professional armies throughout history. Even in today's digital age, studies of social media networks show people maintain meaningful interactions with roughly the same number of individuals.
The biological foundation for this limit lies in our brain’s anatomy. Neuroimaging studies reveal that regions like the frontal lobes, temporal lobes, and limbic system – the emotional center of the brain – determine how many social bonds we can maintain. And their capacity is finite. But how does this biological limit play out in real-world settings?
Our social worlds organize themselves in distinct layers, like ripples spreading from a stone dropped in water. At the center lies an intimate circle of about five people - those we trust completely and contact weekly. Beyond them, approximately fifteen people form our sympathy group - those whose death would devastate us. Then comes a layer of fifty - our broader social circle - and finally, that outer ring of 150 meaningful connections.
This layered structure has real implications for organizational design. Small teams of five or fewer members create an environment of intimacy and trust that enables seamless communication and coordination. A study of software development teams revealed that groups of 3-5 members achieved 72% higher productivity than teams of 9 or more, with less communication overhead and decision-making complexity than with larger groups. In the military, special forces units specifically limit team sizes to 4-5 members to ensure the highest levels of trust and efficiency.
Imagine a thriving community suddenly struggling with disputes and dwindling cooperation. This is what happens in Hutterite settlements when their population grows beyond 150 – a vivid example of Dunbar’s number in action.
Members become less willing to contribute to communal efforts, disputes increase, and the sense of shared purpose diminishes. At approximately 167 members, Hutterite communities deliberately split, forming new daughter settlements. Both parent and daughter communities are carefully structured to maintain optimal sizes - around 150 and 50 people respectively – a pattern that has remained remarkably consistent for over 100 years.
For today's organizations, these findings carry profound implications. When groups exceed their natural size limits, productivity and morale suffer. The solution isn't always staying small, but may instead mean organizing in networks of small units. The key is to find ways to preserve intimate working relationships while accommodating necessary growth.
It’s 3 AM, and three railway workers huddle together under dim lights, sharing steaming coffee and swapping stories to keep the cold at bay. Across town, in a sprawling warehouse, a solitary worker follows computerized instructions through an earpiece, passing colleagues like ships in the night. Research in the UK compared these two contrasting work environments. The railway workers, despite harsher conditions, showed significantly better mental health than their warehouse counterparts.
Why? Before we answer, let’s look at another example. Researchers studied heart attack survival rates across 148 studies and 310,000 people. They discovered that the strongest predictor of survival – surpassing traditional factors like diet, exercise, and air quality – was the number and quality of close friendships. Only smoking cessation came close to matching friendship's impact on survival rates. This same principle of connection applies to the workplace, where close bonds can make a surprising difference
These powerful effects stem from what biologists call the "kinship premium" - our innate tendency to help and value those closest to us family members above all others. The human brain processes close relationships through similar neural pathways as family relationships. In workplace settings, this closeness translates into measurable performance gains: Gallup's thirty-year research reveals that 63% of employees who report having a best friend at work demonstrate high engagement, compared to just 23% of those without close workplace bonds.
Microsoft's Work Trend Index reinforces these findings. Employees with strong workplace relationships consistently generate more innovative ideas, demonstrate better strategic thinking, and collaborate more effectively than their isolated counterparts. When the pandemic forced many organizations into remote work, those companies that had cultivated strong social bonds proved more resilient. Their employees maintained productivity and creative output even when physically separated, drawing on established relationships to overcome distance.
In a separate study involving a warehouse, after management redesigned break schedules to allow team members to overlap, employees began spontaneously organizing shared lunch periods. Within six months, cross-team collaboration increased by 27%, and safety incidents dropped by nearly a third - suggesting that when organizations create space for natural human connection, both performance and wellbeing can benefit.
At a corporate gathering, carefully orchestrated groups of four find themselves sharing unexpected common ground. A coder and an accountant discovered their shared passion for Renaissance art, while two managers from different divisions realised they'd grown up in the same small town. These aren’t chance encounters - but the deliberate result of a forward-thinking organisation working to build stronger teams.
Research has identified seven core dimensions that illustrate how people naturally form bonds. These "Seven Pillars of Friendship" are shared dialect, geographical origin, career experiences, hobbies, worldview, sense of humor, and musical tastes. They predict relationship strength with surprising accuracy. When two people share six or more pillars, they typically form close, lasting bonds. Yet innovation often springs from connecting those who share fewer commonalities. The art, then, lies in balancing these forces.
Consider how Gore, the materials science company, structures its 11,000-person organization. Their model pairs each employee with both a formal leader and a "sponsor" - a learning buddy chosen for their complementary perspectives. This approach creates what Gore calls "lattice relationships" - connections that cross-pollinate ideas while maintaining the comfort of close-knit teams.
Other organizations have found creative ways to apply similar principles to foster collaboration and innovation. Some design office spaces with carefully placed coffee stations at intersection points between departments, increasing spontaneous cross-team conversations by 35%.
A global insurance company assembled teams based on the Seven Pillars model. They found that teams composed of members sharing three to four pillars, but differing in others, outperformed both highly similar and highly diverse groups in innovation challenges. They built stronger bonds when they shared just enough common ground to communicate easily, while maintaining enough difference to see problems from multiple angles. Their success stemmed not from maximizing similarities or differences, but from understanding how to leverage both.
When Oxford University researchers conducted a study of rowing crews, they discovered something remarkable about human connection. Athletes rowing in sync with others produced double the endorphins of those rowing alone, despite exerting identical physical effort. This remarkable finding pointed to a deeper truth: our brains are wired to respond powerfully to shared rhythm and coordinated movement.
This mechanism comes from our evolutionary history. Just as primates build trust by grooming each other, humans bond by triggering the brain’s trust-building chemicals. When people move, sing, or even breathe together, their bodies release endorphins. These natural opiates create feelings of trust and wellbeing.
Organizations that understand this principle have found ways to harness its power. In traditional theaters, directors begin new productions by having cast members participate in synchronized games and exercises - not merely to break the ice, but also, it seems, to create the biological conditions for trust. These synchronized activities level status differences and build the foundation for creative risk-taking that great performances require.
Military training provides perhaps the most powerful demonstration of synchronized bonding at work. From countless drills marching in formation, soldiers build trust through coordinated movement and shared rhythm. This deliberately engineered synchrony creates bonds so strong that units can function seamlessly under extreme pressure. As one retired general explains, these bonds become the foundation of operational readiness, and are more crucial than any technical training.
These findings carry profound implications for modern workplaces. When a tech startup introduced daily communal lunches, they weren't just feeding their employees - they were creating opportunities for natural daily synchrony that brought coding specialists and client teams into a shared rhythm. The resulting improvements in collaboration and trust emerged not from formal policies, but from hearts and minds moving in time.
In Amsterdam's diamond district, dealers exchange millions of dollars worth of precious stones on nothing more than a handshake. This centuries-old market exemplifies trust at its purest: a small, interconnected community where one's word truly is their bond. Yet few modern organizations achieve this level of faith, and understanding why reveals crucial insights about human cooperation.
Research shows that trust typically breaks down through predictable mechanisms. Simulations show that trust can break down quickly. Just a few freeriders – people who take without giving back – can cause entire systems to collapse. Indeed, this mirrors observations from the real-world: studies indicate that just 1% of people tell 25% of all lies. A few bad actors, therefore, can poison an entire organization.
When trust erodes, networks fragment in distinctive patterns. During financial crises, banks restrict lending to only their most reliable partners. Similarly, social networks tend to contract into smaller, defensive clusters. Yet a study at Newcastle University revealed how deeply ingrained our trust instincts are: simply posting a picture of watching eyes above a coffee station's honesty box tripled payment compliance, suggesting that even subtle cues of accountability can maintain cooperative behavior.
However, many organizations respond to trust breakdown by implementing rigid controls, assuming workers need constant supervision. This approach often backfires, however. The Harvard Business Review reports that employees at high-trust companies experience 74% less stress, 106% more energy, and 50% higher productivity compared to those at low-trust organizations.
Dutch healthcare company Buurtzorg demonstrates a more effective approach. Founder Jos de Blok recognized that, while administrative tasks could be standardized, patient care demands flexibility. The company organizes nurses in teams of ten, giving them autonomy to make care decisions while maintaining shared records for continuity. By trusting nurses to make decisions, Buurtzorg transformed patient care. One nurse described how this autonomy let her focus fully on her patients, helping them recover in half the time – while cutting costs by a third.
Building organizational trust requires consistent leadership behavior and shared values. But perhaps most importantly, it demands resisting the temptation to micro-manage in response to occasional breaches of trust. As the Buurtzorg case shows, organizations that design their systems around the trustworthy majority rather than the untrustworthy minority often find their faith rewarded with both more solidarity and greater performance.
The main takeaway of this lesson to The Social Brain by Tracey Camilleri, Samantha Rockey, and Robin Dunbar is that human connection forms the bedrock of successful organizations.
From Dunbar's number of 150 meaningful relationships to the power of synchronized activities and the crucial role of trust, our biological wiring for social bonds directly impacts organizational performance.
Remember: small teams foster intimacy, shared experiences build lasting connections, and trust flourishes when we design systems around the majority's goodwill rather than the minority's misconduct. Whether you're leading a team or building a community, prioritize creating spaces for natural human bonds to develop.
Comments
Post a Comment