Do you know the happiness pie chart? If you’ve read a book or listened to a talk about happiness in the past 15 years, there’s a good chance you heard that 50 per cent of our happiness is determined by our genes, 40 per cent by our activities, and 10 per cent by our life circumstances.
Neat and tidy, the pie chart—originally proposed in a 2005 paper by researchers Sonja Lyubomirsky, Kennon M. Sheldon, and David Schkade—painted a clear picture of what contributes to our well-being. Unfortunately for some of us, the chart suggested, the genes we got from our parents play a big role in how fulfilled we feel. But it also contained good news: By engaging in healthy mental and physical habits, we can still exert a lot of control over our own happiness.
In recent years, critics have raised questions about this simple formula—one that many summaries (including mine above) misreport anyway. And now, a decade and a half after the pie was baked, two of the authors are coming out to say that they agree with many of the criticisms. Even so, they add, their broader message still holds: It’s possible to take deliberate steps to get happier and to stay happier in life.
The proof in the pie
“When you are given a graph that is this clean, it seems reasonable to be skeptical,” warns George Mason University professor Todd Kashdan in his blog post critiquing the pie chart. While the pie has separate slices, he argues, our genes, our life circumstances, and our activities aren’t three isolated factors that influence our happiness directly. They can also influence each other, muddying those distinctions.
For example, Kashdan writes, you may have a gene for leadership, but you won’t necessarily turn into an adept leader unless you find yourself in the right life circumstances (for starters, a supportive social environment). Or, as the University of Groningen’s Nicholas Brown and the University of Leipzig’s Julia M. Rohrer write in their 2019 paper, perhaps you have a genetic disposition toward anxiety—activated by the circumstances of your stressful childhood—that is putting a damper on your happiness in life.
As these examples illustrate, and new studies are showing, genes may be expressed or not depending on what happens in our lives (both what happens to us—our circumstances—and what we choose to do—our intentional activities). In the other direction, genes can influence our tendency to engage in activities that will make us happier, such as exercise, acts of kindness, or pursuing goals.
Even assuming these three factors could be totally separated, critics argue that the 50 per cent for genes and 10 per cent for life circumstances are underestimates—making the 40 per cent figure too high. For example, Brown and Rohrer cite recent research suggesting that the heritability of happiness is 70 to 80 per cent.
The 10 per cent figure was based on studies mainly measuring demographics—like age, income, education, race, and sex, they point out. But the term “life circumstances” is extremely broad and includes (as Lyubomirsky and her colleagues noted in 2005) “the national, geographical, and cultural region in which a person resides.” But studies were done in a single country probably won’t capture the widest possible variation in life circumstances like these, which may explain why the 10 per cent slice is too small.
“Happiness can be successfully pursued, but it is not ‘easy’”―Sonja Lyubomirsky and Kennon M. Sheldon
Finally, even assuming the 50/40/10 was right, there is that crucial misunderstanding that countless speakers and publications have perpetuated: These numbers don’t represent how much of our individual happiness comes from various sources, but how much of the differences among people (in general) do.