“I hate it.” That’s the immediate reaction from neuroscientist Ben Rein when I ask how he feels about the flood of junk neuroscience online—the “dopamine fasts,” “serotonin boosts,” and talk of “regulating your nervous system.” He was up early with his newborn daughter at his home in Buffalo, New York, but on our video call he looks fresh and energetic, quickly clarifying his blunt statement. “Let me be clear: I don’t hate it when it’s accurate, but it rarely is.”
He points to a recent social media reel where a man claimed that reframing pain as “neurofeedback, not punishment” activates the anterior cingulate cortex, a brain region involved in processing pain. “That has genuinely never been studied; you’re just making it up,” Rein says. He posted a sharp response on Instagram, urging content creators to “leave neuroscience out of it.” “That’s why I think it’s especially important for real scientists to be online,” he adds. “We need to show the public what it means to talk about science responsibly and accurately.”
Rein has made this his mission. He is very much a “real scientist,” having published in peer-reviewed journals and completed a post-doctoral fellowship at Stanford, where he still teaches. But he’s also a communicator, breaking down the complex and often murky science of the brain into simple, engaging terms. With 755,000 followers on TikTok and frequent podcast appearances, he tackles audience-friendly, sometimes controversial topics: the causes of autism, empathy, recreational drug use, and now the subject of his first book, Why Brains Need Friends: The Neuroscience of Social Connection.
Could there be a more timely theme? We’re finally waking up to what Rein calls a “post-interaction world.” For anyone wondering about the recent embrace of JOMO (the joy of missing out) or the pandemic-fueled turn toward introversion, Rein’s book offers stark answers. It relentlessly presents evidence that isolation is harmful. Reading it, I felt an urge to gather all my friends and acquaintances immediately.
Research vividly shows how isolation affects our health and wellbeing. “The study on strokes in mice always shocks me,” Rein says, describing how mice given identical strokes fared much worse if they lived alone. “They had more brain damage, were less likely to recover, and more likely to die.” I remember another study cited in his book, which found that among over 300,000 people, those with weaker social ties were 50% more likely to die over seven and a half years. “It’s horrifying,” he agrees. “But it also makes you ask: why? How is that even possible? I like to use the mouse study to help explain it.”
This is Rein’s specialty and a key reason he wrote the book: to “pop the hood” on our social brains by examining what drives us at a biochemical level. He promises to use “no big words” because, as he notes, “I’ve noticed that people who don’t understand science often use big words to sound like they do.” So why is isolation so bad for mice, and what does it mean for us? “When we’re isolated, it triggers a stress response,” Rein explains. This happens in both mice and humans—it’s evolutionary. “The body’s alarm goes off, saying, ‘Hey, why are you alone? This is dangerous. Find your community.'”He explains that the stress response triggers the release of cortisol. “Your body prepares for a challenge, and one effect is that cortisol suppresses inflammation, since inflammation isn’t helpful when you’re trying to escape a saber-toothed tiger.” The issue is that, unlike saber-toothed tigers, isolation persists: the stress becomes chronic, and cortisol loses its effectiveness at controlling inflammation. “With this long-term stress response, inflammation can build up.”
Inflammation is one of the body’s defenses against injury, illness, and stress. It becomes problematic when it lasts too long or occurs in inappropriate situations. Rein admits he dislikes discussing it because it’s often misused as a buzzword online. “Every time I mention it, I worry the audience will think I’m some kind of fraud. But in this context, it’s real—a serious consequence of chronic stress that harms our organs.” Inflammation was identified as the key factor in a mouse study: lonely mice no longer experienced worse strokes than their social counterparts once researchers suppressed the inflammation caused by their loneliness.
A similar process occurs in lonely humans. “Isolated people develop chronic inflammation that likely strains their organs and hinders healing,” says Rein. One study found that stroke patients who reported high levels of emotional support showed “dramatic improvement” in their functional capacity. Another revealed that heart attack patients living alone were twice as likely to die within three years compared to those living with others.
The opposite is also true: being around others prompts the brain to release oxytocin, which Rein calls “the MVP of social bonding” in his book. Oxytocin reduces inflammation, alleviates stress, and aids wound healing. A 2013 study showed that married people, who tend to have higher oxytocin levels, have better cancer survival rates.
The good feeling we get from connecting with others has evolutionary benefits. “Our brains have evolved to make us seek social bonds because they enhance survival,” Rein explains. When we interact with others and release oxytocin, it “triggers a downstream effect, stimulating two powerful neurotransmitters simultaneously: serotonin and dopamine.” Dopamine, he says, “is the brain’s way of reinforcing beneficial behaviors,” while serotonin “is linked to mood.” Together, they are “incredibly effective at making us feel good.”
If connecting feels so rewarding, why don’t we do it more often? Our brains, while helpful in many ways, can also hold us back. “Humans are very poor at predicting how social interactions will go and how they’ll make us feel,” Rein notes. Psychological research shows that we tend to underestimate how much we’ll enjoy socializing, undervalue our social skills, and believe others like us less than they actually do—a phenomenon known as the “liking gap.” Rein traces this inherent social anxiety back to our prehistoric past. “In ancient times, social bonds were delicate—you needed strong connections within your group and deep wariness of outsiders. This caution is meant to make us tread carefully to avoid alienation from our own community.”
Adding to this is the modern challenge of the internet. While online socializing—from WhatsApp groups to video calls—has grown since the pandemic, it’s a poor substitute for in-person interaction in terms of activating the brain’s social reward systems. “When you see facial expressions…”When you interact with someone in person, you hear their tone of voice, see their body language, pick up on social scents, and make eye contact. All of these cues send signals to your brain that you’re truly engaging with another person.
Rein points out that social media users tend to be more anxious, depressed, and lonely—the opposite of what we see in people who socialize more often. He proposes a “virtual disengagement” hypothesis: social cues like facial expressions and body language help our brains interpret others’ emotions. Without these cues online, how can we understand what someone else is feeling? Rein believes this lack of cues contributes significantly to online hostility and division. One way to help, he suggests, is to use more emojis, as evidence shows they trigger brain responses similar to seeing real human faces.
So how can you make the most of in-person interactions? Alcohol, often seen as a social lubricant, might not be as helpful as it seems. Rein explains that alcohol is a depressant because it slows nervous system activity, making neurons less active and reducing thoughtfulness. It also dulls fear and anxiety responses, which can impair empathy and our ability to process social cues—not exactly a recipe for successful socializing.
In contrast, illegal drugs like psilocybin mushrooms and MDMA (ecstasy) have the opposite effect. Lab studies on mice given MDMA showed it “seems to enable a totally unprecedented level of empathy by driving serotonin levels to newfound heights.”
Rein isn’t advocating for illegal drug use. Instead, he notes that getting a dog can have similar positive effects: when dogs and owners look at each other, both experience a significant rise in oxytocin levels. Dog owners also tend to have lower cortisol levels and reduced cardiovascular risks. Rein’s simplest advice is to “upgrade” your interactions whenever possible. Choose options that offer greater social rewards: if you were going to text, call instead; if you were going to call, try a video call; or better yet, meet in person.
While Rein admits he’s “definitely an extrovert,” he emphasizes that there’s no one-size-fits-all approach to socializing. Extroverts and introverts have different social needs. However, everyone benefits from some level of social interaction and suffers without it. This can create a vicious cycle: research shows that isolated people don’t experience neurochemical social rewards as strongly as those who are well-connected.
The neuroscience of connection reveals a fascinating mix of selfish and selfless motives. We’re individually motivated by neurochemical rewards to act socially or even altruistically. Seeing someone in pain—including social pain like embarrassment or exclusion—activates the same brain areas linked to pain in ourselves, which can drive us to help. Rein mentions a striking study where rats given benzodiazepines (which reduce anxiety and unease) were much less likely to free a trapped companion.
This interplay is reflected in Rein’s book. His arguments for socializing can seem practical, functional, or even self-interested: connection is good for us, like getting enough vitamin D or sleep. He presents socializing as a longevity hack, similar to how fitness is promoted. Rein compares it to exercise: “You have such a clear incentive where you can look in the mirror and say, ‘I look pretty fit, and I want that to continue, so I’m going to do it.’ With socializing, people don’t have that visible incentive.”
By highlighting the health benefits, Rein hopes to give people a personal reason to reach out. But his goal is actually much more idealistic. “I worry about the way our societies are fracturing. If this continues…”If this book can show people that talking to strangers, giving compliments, and fostering positive connections in your life is beneficial, it gives them a reason to do something that also helps humanity. Sleeping well or going to the gym might not make the world a better place, but being kind to those in your community truly does.
Why Brains Need Friends: The Neuroscience of Social Connection is available now from Quercus. To support the Guardian, you can order a copy at guardianbookshop.com. Delivery charges may apply.
Frequently Asked Questions
Of course Here is a list of FAQs about the connection between friendship and longevity designed to sound like questions real people ask
General Beginner Questions
1 Is there really a link between friends and living longer
Yes strong scientific studies consistently show that people with robust social connections tend to live longer healthier lives compared to those who are lonely or isolated
2 How does being social actually add years to my life
It works in several ways it reduces chronic stress encourages healthier behaviors and provides emotional support that helps you cope with challenges
3 What counts as a social connection Does it have to be a best friend
Not just best friends Meaningful connections include family close friends neighbors community group members or even regular friendly interactions with people at a club gym or volunteer organization
4 Im an introvert Does this mean Im at a health disadvantage
Not at all Its about the quality not just the quantity of connections A few deep fulfilling relationships can be just as powerful as having a wide circle The risk comes from feeling chronically lonely or disconnected not from enjoying solitude
Benefits Science
5 Whats the physical effect of loneliness on the body
Chronic loneliness can trigger sustained stress responses leading to higher inflammation increased blood pressure and a weakened immune systemall factors linked to heart disease dementia and other agerelated illnesses
6 Are the health benefits of friendship comparable to things like diet and exercise
Research suggests the impact is similar Some studies indicate that strong social ties can be as beneficial for longevity as quitting smoking and may have a greater effect than wellknown factors like obesity or physical inactivity
7 Can online friendships provide the same longevity boost
They can be a valuable supplement especially for maintaining longdistance ties However inperson interactions typically offer more robust benefits due to physical presence nonverbal cues and the greater likelihood of shared activities A balanced mix is ideal
8 Does marriage or having a partner replace the need for friends
While a supportive partner is hugely beneficial its generally not enough on its own Friends provide a unique and diverse support network Relying solely on one person can also put strain on that relationship
Common Problems Practical Tips
