Science is making the world get more and more expensive. When science brings out a new gadget it costs more than the others. People have to earn more to buy it. So science is making the world more difficult, more complex. It makes people run more. What we need is to rest more, talk more, walk more, fuck more and enjoy things in life more. There’s a limit to what Europeans call technological and industrial development. When that limit is achieved society just crumbles. That’s why I see the day Europe, America and Russia will come to a standstill.

So to think about whether we can sustain technological progress, we have to think about whether we can keep exponentially growing the number of researchers. Consider that there are two ways to do this. First, you can increase the share of the population that is devoted to research. Indeed, we’ve been doing a lot of that, so that’s been the source of most of US technological progress in the last few decades. Technology-driven growth of US per-capita incomes has averaged about 1.3 percent per year. A full percentage point of that comes from increasing the fraction of the population doing R&D and from improving the allocation of talent, such as by reducing gender and racial discrimination.

The second way by which you can increase the number of researchers is by increasing the total size of the labour force: that is, you can grow the population. Over the last few decades, population growth has contributed about 0.3 percentage points to the United States’ technologically driven per-capita growth rate.

Here are two reasons why this might happen. First, perhaps, as political economist Benjamin Friedman argues, people are more morally motivated in times of economic growth. When the economy is growing, everyone can be better off than they were in the past. This means, Friedman argues, that citizens will worry less about how their life compares to the lives of people around them and will be more supportive of generous, open, and tolerant social policies. And if you look at the historical record, he claims, countries tend to make moral progress—becoming fairer, more open, and more egalitarian—during higher-growth periods, and they tend to morally regress during periods of stagnation.

A second reason ties back to our earlier discussion of cultural evolution. When technological innovation is possible, there are great economic gains to be had from critical thinking and scientific inquiry; and since economically successful cultures gain more members, cultural evolution currently selects for traits conducive to science. As a side effect, so this argument goes, we apply our critical capacities to moral issues, too, and therefore make moral progress. In a stagnant world, the economic reasons to engage in critical thinking and scientific inquiry would be much weaker. Instead, other values would be selected for, such as those favouring hierarchy and conformity, which have guided so many societies in the past.

It is common, and natural, to tell the history of innovation through the exploits of men of genius, such as Edison and Tesla, and pioneers such as Berners-Lee and the Wright brothers. But if the Wright brothers had not flown in 1903, someone else would have done something very similar in some other location. Collective intelligence develops when the accumulation of collective knowledge reaches a point at which talented people identify problems that this shared knowledge can be employed to solve. And it is also common, and natural, to describe the history of innovation through the introduction of new gadgets, from aeroplanes to iPhones. I have taken running and apples as examples to emphasise that the

growth of collective intelligence has a range and applicability that extends well beyond technology.

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.