Most of us assume happiness comes from achieving things—money, success, the perfect relationship. And while these things can make us happier, they don’t always create the deep, lasting happiness we expect.
In fact, the longest-running study on happiness proves we’ve been looking in the wrong place all along.
The Harvard Study of Adult Development
The longest running study on happiness started back in 1938. It’s been running for 87 years – longer than the average human lifespan!
The Harvard Study of Adult Development follows two study groups – The Grant Study group of 268 privileged Harvard Graduates at about 19 years old and The Glueck Study group of 456 men from the toughest neighbourhoods of Boston aged between 11 and 16.
The original cohort was not the most diverse – all caucasian males (sigh, roll eyes). But it now includes over 1300 descendants of the original men.
As the men went about their lives – progressing in their careers, getting married, (getting divorced!) having families, retiring – the study tracked them.
They answered questions, shared health records and were interviewed every 5-10 years.
As technology developed, so did the data collection. They now do brain scans, blood tests, DNA samples and even testing hair samples to see how much of the stress hormone cortisol is in there!
Around 60 of the original study group are still alive, now in their 90s.
So what did the Harvard Study discover about happiness?
They found that the single biggest secret to a long and happy life wasn’t money, success, or even genetics—but something much simpler.
People who had strong, warm relationships—whether with family, friends, or a partner—had higher levels of life satisfaction and emotional well-being.
But it wasn’t just about feeling good; it also affected their physical health!
People who felt socially connected had lower blood pressure, stronger immune systems, and even less pain later in life.
We often think of loneliness as just an emotional experience the Harvard study found that it actually has a physical impact on the body.
- Increases levels of cortisol (the stress hormone), which can lead to inflammation and a weakened immune system.
- Raises the risk of heart disease and other chronic illnesses.
- Speeds up aging—in some cases, lonely individuals showed signs of cognitive decline up to two years earlier than those with strong relationships.
Loneliness turns out to be as dangerous as smoking 15 cigarettes a day!
Lonely people even live an average of 8 years less!
The more friends, the happier we’ll be?
Speaking as an introvert, that sounds exhausting to me!
Thankfully, we don’t need a huge social circle to be happy.
The study found that it wasn’t the number of friends that mattered—it was the depth of those relationships.
People who had at least one or two close, reliable friends were much happier than those who had large, superficial social networks.
Being able to turn to someone in times of stress made a bigger difference than simply having people to socialize with.
It also didn’t have to be a romantic relationship—friendships and even positive work relationships had significant benefits.
But this isn’t all sunshine and roses.
Social connections that are toxic or being in high-conflict relationships led people to have higher levels of stress and cognitive decline as they aged.
So while, married people tend to be happier and live longer than unmarried people – this is not necessarily the case if you and your spouse do not get along!
And what about if you prefer being single and you enjoy spending time on your own?
Well the study does acknowledge that being alone is not the same as being lonely.
If you’re anything like me, you love your friends, but only have so much social battery. I need my alone time to recharge.
The difference is-loneliness is an unwanted lack of connection, but solitude can be a choice.
In fact, it’s needed for introverts and it can be fulfilling so long as we maintain a few deep and meaningful relationships.
How do you know if your relationships are deep and meaningful?
Test 1
You could try the often shared test of:
“Who could you call at 3am in a crisis?”
Which is a quick way to check who will be there for you no matter what.
But there’s more to a deep relationship that crisis support.
That’s where this next activity I designed comes in.
Test 2
When I first designed the Supportive Relationships tool, it felt weird, like I was creating Top Trumps cards for people!
But it’s not about ranking them against each other, it’s about looking at where different forms of support come from in your life.
And more importantly you can see which relationships need work, and which areas of your life might need more support.
Get your copy of the the Supportive Relationships Tool here.
By giving each relationship quality a number between 1-10, you’re forced to honestly assess it.
✅ Emotional Support – Can you be vulnerable with this person? Do they listen without judgment?
✅ Reliability – Can you count on them in difficult times? The 3am crisis call, turning up on their doorstep randomly.
✅ Mutual Growth – Do you both encourage each other’s personal growth?
✅ Enjoyment & Ease – Do you genuinely enjoy their company? Does the relationship feel natural, not forced?
✅ Gives or drains energy? – Do you feel energized after hanging out with them? Or exhausted?
✅ Trust & Honesty – Can you share your true thoughts without fear?
✅ Make time for each other – Do you both make time for each other and make an effort?
✅ Share meaningful moments – This could be celebrating successes, or important events like weddings, birthdays or holidays together.
I was surprised when I did this activity that an old friend who I rarely talk to actually had a deeper relationship with than people who I speak to more regularly.
Which brings us to an interesting point.
Developing and building deep relationships
How do you develop your relationships to the point where they become deep and meaningful?
And if you don’t have enough good relationships to start with, how can you meet some more people?
We live in the most connected era in human history—instant messages, video calls, social media.
You can reach anyone, anywhere, in seconds.
And yet… loneliness is at an all-time high.
It’s even been declared an epidemic because of its effects on our health.
The UK and Japan have even appointed ministers for loneliness!
And in 2023, the World Health Organization declared loneliness a global public health concern.
Social media and messaging make it easy to stay in touch with people—but it doesn’t mean we’re actually connecting.
A like, a comment, or a quick “how’s it going?” might feel social, but it’s not the same as real, meaningful connection.
And even worse, it reduces real-life interactions.
The disappearance of free to use third spaces like libraries and community centres aren’t helping either.
Now if you want to meet new people, you have to buy a drink or some food.
So it’s harder than ever to meet new people outside of your job, especially if you’re strapped for cash.
Gone are the days of being a child and going up to someone you didn’t know and asking if they’d be your friend. But it’s actually not hugely different….
When you’re a kid you make friends because you see some kids playing a game that you like and you want to join in, or you always see the same kids at the park.
It’s the same thing as an adult.
It takes spending about 50 hours with an acquaintance before they become a casual friend. But you can speed that up, by doing activities together.
Two years ago, me and my partner relocated to a new town where we didn’t know anyone.
As boardgamers, we needed friends to play games with!
So we joined the local board game group and started working from a co-working space a few days a week.
For you, making new friends might mean, joining an art class, dance group, cooking course or improv troupe.
Or maybe volunteer for a cause you care about.
Or join a local sports team, book club or gaming group.
Something that naturally encourages interaction.
Even just by showing up to the groups regularly, you’ll start to recognize people and will naturally chat to them over time.
The ‘mere exposure effect’ from psychology is at work.
We tend to prefer things we are familiar with.
The more we see someone, the more we are likely to like them even if there’s no other reason to.
While you’re at a group, try being the one to reach out first even if it feels awkward.
A study by the American Psychological Association found that we underestimate how much others appreciate it.
Most people want to connect but are afraid to make the first move.
So if you have a good conversation with someone, suggest something small, like:
“We should grab a coffee sometime!”
“I’m thinking of checking out that new art exhibit—want to come?”
While at the co-working space one day, I was chatting to someone in the kitchen about hobbies and it turns out they liked boardgames too.
So I asked if he and his wife would like to play games in the co-working space one night after work.
I’m happy to say they’re now friends!
After spending another 30-50 hours with a casual friend, they may turn into a friend, and after another 100 hours a good friend.
Of course, it’s not just about you wanting to be friends with someone. They have to want to be your friend too.
To deepen friendships, when it feels right, ask questions that steer the conversation towards more personal stories, dreams and values. More deep talk, less small talk.
Things like:
- “What’s been the highlight of your week?”
- “What’s something you’ve always wanted to try but haven’t yet?”
- “What’s one piece of advice you’d give your younger self?”
- “How do you define success for yourself?”
Research shows that these questions help us develop deep and meaningful relationships and that we tend to overestimate how awkward they will be.
But is that really all we need for a long, happy and healthy life?
Some deep relationships?
Well, not entirely. There are two other things.
The second most important thing for a happy life
The second most important is supported by countless studies and is found to be hugely important in the 5 Blue Zones too – the areas of the world where people live longer than the rest of the world… And that’s exercise.
Even just walking for 15 minutes a day increased longevity by 2 years.
So my dog is helping me live a happier and healthier life every time we go for a walk!
But it’s not the case that the more exercise you do, the longer you live.
Between 500 calories to around 3500 calories per week the more exercise people did, the longer their life expectancy. But doing more than this amount of exercise and the death rates actually increased slightly.
The biggest benefits were seen from social exercise like walking with friends or playing sport, had an even bigger impact.
But there’s one thing that we’ve not looked at at all so far. And this is the one that most people think will give them a long and happy life. And it turns out, it does matter.
Money and happiness
You’ve likely heard the quote –
Money can’t buy happiness.
Well, can’t it? That’s what the famous study by Daniel Kahneman & Angus Deaton (2010) found out.
Using data from a national US survey of 450,000 people, the people were asked to rate their life satisfaction, an overall sense of how their life is going and their emotional well-being (how much positive emotion or happiness they felt the previous day) on a scale of 1-10.
They found that the day to day happiness increased with income but levelled off after a certain income amount. How much? $75,000. That’s around $109,000 today.
Which makes sense. Basic financial security for food, housing, and healthcare will lead to less feelings of stress which will lead to higher happiness.
Reminds me of this quote –
Money can’t buy happiness. But poverty can’t buy anything.
However, even day to day happiness didn’t continue to improve, overall life satisfaction did continued to improve with higher income.
A 2021 study, challenged these findings
It found that happiness actually increases up to $100,000 dollars and it didn’t plateau at this point. It continued to rise! But not for everyone!
For the most unhappy group, happiness rises with income until $100,000 (around $116,500 today) , then stops even as income rises.
For people in the middle range of emotional wellbeing happiness increased along with income, and for those who were already happy before more money, their happiness increased the most!
So if you’re already happy, then more money will help you feel even happier!
But if you’re unhappy, all the money in the world won’t lead to high emotional wellbeing. Perhaps these people in the study can relate to this Spike Milligan quote
“Money can’t buy you happiness but it does bring you a more pleasant form of misery.”
Spike Milligan
So what can we do with this knowledge of money to help us make our lives better?
Earning more is the obvious first answer! There are tons of resources out there on how to start a side hustle around your 9-5 but they do need time to get going.
The good news is, you can work on increasing your happiness before the extra money starts coming in! Then when it does, you’ll be even happier!
As we’ve learned, focus on building and deepening your relationships and get your body moving, even just a little each day makes a big difference.
And this doesn’t need to cost anything, you can have video calls for free. When I go for a walk with a friend I take a thermos and snacks to save us money buying tea and cake.
Even if we don’t increase the amount we earn – research shows that feeling more in control of our finances reduces stress and anxiety.
Mental budgeting can do this.
Start with categories like groceries, gas, entertainment, bills, debt repayments etc. Put spending limits on each one and check in with yourself throughout the month to keep on track.
Remember to include some budget for socializing and deepening relationships 🙂
If money is tight, invite friends round for dinner, or if they live far away plan a virtual night in. Steam a movie together, play some online games and eat together over video call.
A 20 year study by Dr Thomas Gilovich at Cornell University found that our experiences give us more lasting happiness because thanks to our ‘headonic treadmill’, we quickly get used to having new things, like a new phone or a car and return to our baseline of happiness.
Plus, we raise the bar. We want our next phone to be even better than the last one.
And we can fall into the trap of comparing our possessions to others.
We’ll be happy with our new house for a while, until our friend moves into a better one. But there will always be someone with a better one!
The best thing is, that not only do experiences give us longer lasting happiness afterwards, they also make us excited leading up to the experiences.
Whereas, waiting for possessions can lead to impatience and frustration instead.
Then when we do finally get the thing, we experience temporary happiness which Dr Elizabeth Dunn calls the Puddles of Pleasure.
Then we’re left wanting more.
Things may last longer than experiences, but it’s the lasting memories from experiences that truly matter for a happy life.
Even if you have meaningful relationships, exercise regularly and have financial security – you might still feel like there’s something missing. Fulfillment is a very personal thing. To find fulfillment in a way that’s unique to you, check out this video on finding fulfillment and purpose.
Watch the video on YouTube
References
The Harvard Study of Adult Development.
https://www.adultdevelopmentstudy.org
Loneliness and Social Isolation as Risk Factors for Mortality: A Meta-Analytic Review
https://journals.sagepub.com/doi/10.1177/1745691614568352
The power and prevalence of loneliness
https://www.health.harvard.edu/blog/the-power-and-prevalence-of-loneliness-2017011310977
Social isolation contributing to higher rates of morbidity and mortality in older adults
https://pmc.ncbi.nlm.nih.gov/articles/PMC3166409/
How to make friends? Study reveals how many hours it takes
https://news.ku.edu/news/article/2018/03/06/study-reveals-number-hours-it-takes-make-friend#:~:text=In%20a%20new%20report%20published,and%20more%20than%20200%20hours
Getting beyond small talk: Study finds people enjoy deep conversations with strangers
https://www.sciencedaily.com/releases/2021/09/210930101411.htm
Marital Happiness and Psychological Well-Being Across the Life Course
https://pmc.ncbi.nlm.nih.gov/articles/PMC3650717/
UK Campaign to End Loneliness
https://www.campaigntoendloneliness.org/
Social Connection Report: The Ties That Bind and Nurture
https://capita.org/publication/social-connection-report-the-ties-that-bind-and-nurture/
Physical activity, all-cause mortality, and longevity of college alumni
https://pubmed.ncbi.nlm.nih.gov/3945246/
Does more money correlate with greater happiness?
https://penntoday.upenn.edu/news/does-more-money-correlate-greater-happiness-Penn-Princeton-research
Impact of financial literacy, mental budgeting and self control on financial wellbeing: Mediating impact of investment decision making
https://pmc.ncbi.nlm.nih.gov/articles/PMC10645357/#pone.0294466.ref061
Mental budgeting and the management of household finance
https://scholar.google.com/scholar?cluster=18219552878586440093&hl=en&as_sdt=0,5
To Do or to Have? That Is the Question.
https://psycnet.apa.org/record/2003-10055-017
UK Minister for Loneliness
https://www.bbc.co.uk/news/uk-42708507
World Health Organization Declares Loneliness a Global Health Concern
https://www.who.int/news/item/15-11-2023-who-launches-commission-to-foster-social-connection
The Surprise of Reaching Out: Appreciated More Than We Think
https://www.apa.org/pubs/journals/releases/psp-pspi0000402.pdf
Experienced well-being rises with income, even above $75,000 per year
https://www.pnas.org/doi/10.1073/pnas.2016976118