Have you ever had that sense of “I just really need some bro time right now!”? Or “Let’s go grab a beer with my buddies.” Well, stop feeling bad for those beers because science has shown that you’re really just doing yourself a favour.

Science has shown that for guys a beer out with their buddies once or twice a week is an essential part of bonding, supporting both social relationships and personal health. Not surprisingly, the news spread quickly on major newspapers after Robin Dunbar, acclaimed evolutionary psychologist at the University of Oxford published the findings of his study.

For instance the Business Insider titled “Men need to get drunk to stay healthy” or the Vancouver Sun wrote “Boys night twice a week keeps guys healthy, study says”. Now naturally my inner scientist has its trouble with such simplified, mainstream newspapers that live more on headlines and ads than quality journalism and accuracy of their content.

So I decided to dig into the relevant scientific articles myself – I went right to the journal papers – to look at the real data. What has science shown about reasons, effects and benefits of your “beer with buddies” or “weekly bro time”?

Meet The Man: Robin Dunbar

Before we look at the findings, let’s take some time to introduce the lead researcher of these studies, a man by the name of Robin Dunbar. He is one of the world’s most famous evolutionary psychologists. Taking a look at this list of publications you will be sure to find some amazing research he has done.

You might be wondering…

What is evolutionary psychology?

A definition comes from one of the most prominent researchers in this scientific discipline not older than 20 years at most:


[stextbox=”info” caption=”Evolutionary Psychology – a definition”]

“The term evolutionary psychology can be defined as the scientific study of human thought and behavior from an evolutionary perspective and focuses on four big questions (Buss, 1999):

  1. Why is the human mind designed the way it is and how did it come to take its current form?
  2. How is the human mind designed, that is, what are its parts and current structure?
  3. What function do the parts of the mind have and what is it designed to do?
  4. How do the evolved mind and current environment interact to shape human behavior?”[/stextbox]

Dunbar himself researches social bonding from a perspective of evolutionary psychology. He likes to understand

“insights how humans have managed to create large scale societies using a form of psychological that is evolutionarily adapted to very small scale societies, and why these mechanisms are less than perfect in the modern world.”

He is probably most famous for the finding that across all countries, continents and cultures the typical size of our social circle including inner and outer circles is approximately 150 people – or what has become famous as “Dunbar’s number”.

If you want to learn more about my currently favorite subdiscipline of psychology, I can highly recommend you the following introduction – written by Dunbar himself and a few of his colleagues.

Now science has found that it is not only beneficial, but in fact it is absolutely essential for men’s health to get their boys’ night out. How come? Dunbar says that it is essential to get together regularly in person in order to build and maintain good relationships with other men.

I’m Sorry, BUT…It’s Not The Beer

First of all, to all of you who wanted to cheer to these news with a third or fourth pint, hold it right there! I have to disappoint you. Looking at the actual research, the published papers, there is NOT ONE SINGLE WORD about the role that beer might play in supporting the benefits for men.

In fact…it seems that all these big news about the beer come out of a simple comment Dunbar gave when interviewed by the Daily Mail back in 2012 when the study was published (only a few weeks ago newspapers re-discovered this 4-year-old-story…). Dunbar said in summarizing the findings

“Bonds can be formed through a range of activities from team sports to male banter – or simply having a pint with your pals on a Friday night. However, the key to maintaining strong friendships is to meet up twice a week and do stuff with the four people closest to you.”

The second part of his quote – which is way more important in my opinion – was largely lost by mainstream media unfortunately, but I’m sure the first part allows for more clicks on their advertising sponsors…well, you see it right there.

Beer is only one possibility, but why not engage in healthier ways like doing sports together or just having a good time discussing over healthy food?

Okay, so let’s look at the real facts. What Dunbar and colleagues actually found will make you perfectly justify and reason the next pub evening, but it might also allow you to build more positive and empowering rituals into your weeks – to maintain and build your closest friendships and come out a more balanced men on top of that…

And LADIES, there are some huge benefits in all of this for you too, so keep on reading…

Here are the real facts:

a) Male friendships improve by doing things together.

How do men and women maintain and cultivate their same-gender-friendships (male friendships/female friendships) even when geographically separated for a longer amount of time? This was the question Dunbar and colleagues researched in a 18-month-study back in 2011.

Differences in how men & women maintain and deepen friendships

The quality of the relationships was measured by the construct of “emotional closeness”. Study participants were asked to think of the other person and their relationship and then rate the degree of emotional closeness present.

There were some expected, but also some SURPRISING findings. First of all, the hypotheses that the longer they had not seen each other or not talked to each other, the less emotional closeness would be reported was confirmed.

Yet this finding wasn’t really surprising. A more interesting finding however occured when they checked for gender differences.

Male friendships do not really improve or become closer when they talk longer, but they do improve strongly when doing things together. Women on the other hand generally come closer by talking for long amounts of time with one another. As Dunbar explains in his TED Talk

“If girls keep conversation up and talk to each other a lot, it helps to prevent decay on the relationship.
What prevents boys relationships decaying is doing stuff together.” 

So the inspiration for boys night out is the following: guys need to meet physically and hang out together in the real world to maintain their close friendships. And what could be better than a night out with the boys and pubbing, maybe clubbing?

Facebook, WhatsApp, and phone conversations won’t cut it for men – this was another finding of their study. While women can maintain their relationships quite well this way, for men this is not the case. Dunbar summarizes this in the interview with the Daily Mail

“There is a big sex difference though … girls are much better at maintaining relationships just by talking to each other.”

b) The ideal group size for laughter and bonding is 4 people.

In 2012, Dunbar finished a study observing social groups in bars in London, Calais, Paris, and Berlin, where he studied the average size of groups in bars and how they interacted with one another. Depending on the groups they say, they distinguished between “social groups”, “interaction groups” and “laughter groups”. The key findings were that

  • most groups (so called “interaction groups”) consisted of around 4 people – the average was 4.21 people
  • laughter groups were significantly smaller than interaction groups, the average 3.35 people – in these groups LAUGHTER WAS MOST LIKELY TO OCCUR.

Dunbar reasons in the paper that “there may be an optimal group size for laughter to occur.” And once the group grew beyond these 3.35 people on average, the likelyhood of laughter decreased.

Why Laughter Matters

Laughter matters because it promotes the release of endorphines, that induce feelings of excitement and euphoria and amongst others an increased pain threshold in individuals. This release of endorphines does not occur if we engage just in normal conversation.

In other words: the recommendation for guys is to go out in groups of no more than 4 people in order to maximize their chances of having a good time and lots of laughs.

As Dunbar observed, in groups larger than four on the other hand, people tend to just go into more normal conversations – therefore the name “interaction group”.

The reasons for this may be that it is hard for everyone to understand each other in loud settings or could also be the more intimate nature of humor over normal, socially accepted interactions.

c) Males bond over laughter and doing stuff together

And while our ancestors and closest mammal colleagues, the apes, got this endorphine release from physical touch and what is called grooming, we humans are part of larger social groups in complex societies, so we developed laughter as a way of bonding and “grooming-at-a-distance” as Dunbar calls it.

Male chimpanzees engaging in social grooming

In short: I am not able to groom 3 to 4 people at the same time, and we don’t have the time to all groom each other, so we tell jokes in order to “groom” more people at the same time.

While this may sound a little bit weird, it makes perfect sense once you dig deeper into evolutionary psychology…the branch of psychology that promises deepest levels of understanding of modern societies…if you aren’t afraid to go into a bit of Darwinian theories.

Once again, therefore my book recommendation to you:



So let’s summarize these findings and put them into a conclusion that goes well beyond the “guys need to get drunk with friends twice a week” mumbo-jumbo that mainstream, headline-dependent media put together.

We started off by saying that male friendships are maintained and develop more closeness differently than women do. While women bond well by regularly talking with each other (phone, Skype, in person…), men bond best by doing things together.

This could be doing sports together, something like cart racing, or of course a regular boys night out which typically includes a pub and bar or other forms of alcohol consumed.

This serves to justify the pub of course.

Another piece of evidence for the boys night out is that it tends to be a group size that is optimal for laughter to occur, which accelerates and intensifies social bonding through the release of endorphines.

If groups get larger than 4 people however, the amount of laughter tends to decrease strongly, causing the positive endorphines effect to disappear. Hence other social gatherings with larger groups are suboptimal –> +1 for the boys night out.

Moreover: social networks, or Skyping won’t cut it for men, as they need to meet in person, face-to-face, and engage in physical activities in the real world. +1 for the weekly or twice-weekly pub meeting.

Men need to meet in the real world

Now, having said all of this, guys, listen up: NOBODY said it has to be the pub and the beer. However, it must be real world, physical activities, regular and in groups of up to four. My ideas: why not go hiking, biing or playing a tennis game together?

You can still grab the after-game-drink, laughter will occur during and after the activities, and you exercised your body along the way.



WOMEN, in the hope that you too have been reading up to this point…here is how you can benefit from this too. The regular boys night out will make your man happier, more relaxed and balanced – as the endorphines ensure a more pleasing and positive partner around you.

So while guys now have science to support their argumentation for the BNO, so you too trust these findings and send your man out – he will be better company once he comes back 🙂

So to summarize this: boys night out – with the 3 best and closest friends is a perfect situation for bonding, releasing endorphines, and enjoyment along the way. Whether you drink beer or something else is up to you, Dunbar summarizes the findings best in the quote I will repeat:

“Bonds can be formed through a range of activities from team sports to male banter – or simply having a pint with your pals on a Friday night. However, the key to maintaining strong friendships is to meet up twice a week and do stuff with the four people closest to you.

[stextbox=”info” caption=”Sources”]


Dezecache, G., & Dunbar, R. I. (2012). Sharing the joke: the size of natural laughter groups. Evolution and Human Behavior, 33(6), 775-779.

Dunbar, R. I., Baron, R., Frangou, A., Pearce, E., van Leeuwin, E. J., Stow, J., … & Van Vugt, M. (2011). Social laughter is correlated with an elevated pain threshold. Proceedings of the Royal Society of London B: Biological Sciences, rspb20111373.

Roberts, S. G., & Dunbar, R. I. (2011). Communication in social networks: Effects of kinship, network size, and emotional closeness. Personal Relationships, 18(3), 439-452.