In 2010 Angus Deaton and Daniel Kahneman at Princeton University tried to quantify the relationship of money to happiness using a year-long Gallup survey that resulted in a massive dataset of 450,000 daily responses from a nationally representative sample of one thousand people.

Deaton and Kahneman showed that in the United States, $75,000 seemed to be a kind of magic number at that time. Once a household income was more than $75,000 per year, which was close to the average family income in the U.S. at the time of the study, the amount of money that people earned showed no clear relationship to daily reports of enjoyment and laughter, which were used as indicators of emotional well-being.

For some people in the study, making the economics work proved relatively easy, whereas for others it proved much more difficult. Family wealth served as a significant means to pursue a hedgehog in only six of the 34 lives we studied, whereas in ten of 34 cases people endured at least one significant phase of scarcity while in pursuit of a hedgehog. Yet whether easy or difficult (or somewhere in between), they committed to focus their inner fire in line with their encodings and they figured out how to make the economics work.

The crucial question is, Does the inner fire for what you’re doing far exceed the tax you have to pay to be able to do it? If not, can you change some aspect of it to lower the tax rate? Recall Barbara McClintock leaving the University of Missouri to find a more suitable home at Cold Spring Harbor, thereby lowering her tax rate to a more sustainable level. There might be a point when the tax rate becomes too large to pay, and you decide it is time to leave behind the activity that you love to do. Though the dominant pattern in our study is that so long as they were in frame with their encodings and full of fire for what they were doing, our subjects largely made changes and adjustments to be able to stay in hedgehog mode.

We found scant evidence that the people in our study had an explicit goal of working until a target retirement age to be followed by a life dominated by leisure. The vast majority of people in this study remained engaged in some permutation of a hedgehog well past the age of 60, in some cases into their 70s, 80s, even 90s. That said, nearly half the people in our study had a “retirement” from one hedgehog partway through their lives and faced the challenge of transitioning to the next one. Sometimes these were relatively smooth transitions, such as Tenley Albright’s shift from skating to surgery.

All of which brings us to one of the most important points of this entire book: the difference between finding “the” hedgehog and finding “a” hedgehog. If we hold to the idea that each of us has only one hedgehog and much of life depends on whether we find it, then this would be a very depressing study. But if we embrace the view that each of us has many possibilities to potentially discover— that the constellation of encodings within each of us is vast and largely undiscovered— then the challenge changes dramatically from the low odds of finding that one elusive unicorn hedgehog to finding just one out of many possibilities.