Did you know there are more than 2,000 definitions of happiness in academic literature?

Two thousand. Spanning thousands of years of philosophy, psychology, biology, and cross-cultural study, and the world's greatest thinkers still haven't fully agreed on what the thing actually is.

In recent years the science of happiness has exploded and some things do show up consistently across large studies. Close relationships. Physical activity. Gratitude. Acts of kindness. These tend to support wellbeing across many thousands of participants and the research behind them is solid and worth taking seriously.

But with all of this, there’s a catch.

Scientists report something called the N number in their studies. The number of participants. A study with ten thousand people carries a lot of weight. But when it comes to your actual life, the most important experiment has an N of one. Just you. And what works for most people most of the time may not work for you specifically, in your specific life, with your specific nervous system and history and preferences and the particular way you happen to be wired.

My wife and I are a good example of this.

I love a cold shower. Not lukewarm. Not refreshing. Cold. The kind that makes you gasp a little when you step in and then, about thirty seconds later, produces a feeling I can only describe as emerging from the water like a majestic unicorn.

My wife, on the other hand, sees nothing appealing about the idea of being cold. In fact, after she has me place fleece socks on her delicate, chilled little toes, she wraps herself up in a heated blanket, transforming it into a makeshift thermos for her body. The idea of a fleece sauna does not appeal to me… at all.

When it comes to things that make us feel better, this is one space where we’re both correct.

Cold showers have real, documented benefits for mood and energy. So does warmth, comfort, and the particular kind of cozy that comes from being wrapped in multiple blankets while the heat runs in August. Different inputs, similar outputs. Both of us are doing something that works for our nervous systems even though what we're doing looks nothing alike.

The point is that no one approach to feeling better is superior. It's that we're all different. And treating wellbeing advice like commandments handed down from a mountain is a reliable way to end up doing things that don't actually help you while feeling guilty that they're not helping.

What I've learned to do instead is treat happiness advice like a set of hypotheses worth testing. I also see happiness as a kind of creative tinkering. It’s the same instinct that goes into storytelling and figuring out what works on the page. You try something. You observe what happens. You ask whether it's actually making a difference. And then you keep it if it does and let it go if it doesn't.

That's the happiness experiment. And the most important thing about it is that you're the only one who can run it.

Here's your one thing for this week.

Pick one wellbeing practice you've been meaning to try or one you've been doing out of obligation rather than because it actually helps. Or, if you need some starters, go back through any of the previous 75 newsletters to find something ;)

Run it as an experiment for seven days. Notice what happens. Be honest about whether it's working. And then make a decision based on your own evidence rather than someone else's study.

You are the N of one. Act accordingly.

That's Volume 076. Here's to cold showers that feel like emerging as a majestic unicorn, heated blankets stacked two deep, and the permission to stop following the happiness rulebook and start running your own experiment instead.

Until next time: breathe deep, test your hypothesis, and chill the duck out.

Jason

Academic literature contains more than 2,000 definitions of happiness, reflecting thousands of years of philosophical, psychological, biological, and cross-cultural study without a single agreed upon definition. Large scale happiness research consistently identifies close relationships, regular physical activity, gratitude practices, and acts of kindness as the most reliable contributors to wellbeing across diverse populations. The concept of N number in research refers to the number of study participants, with larger N producing more generalizable findings but never eliminating individual variation. Research on cold water immersion shows measurable benefits for mood, energy, and stress regulation. Research on warmth, comfort, and physical coziness shows parallel benefits through different physiological pathways, supporting the conclusion that different inputs can produce similar positive outcomes depending on individual wiring. Positive psychology researchers including Sonja Lyubomirsky have written extensively on the importance of person-activity fit, the idea that the effectiveness of any happiness practice depends significantly on the individual engaging in it.