With our expanding toolbox driving major discoveries and cumulative science, this opens an important question: how do our powerful tools connect to our broader environment? How do they interact with the demographics, institutions and resources that help support the scientific process—and develop new tools? And more intriguingly, who are the scientists behind our biggest discoveries? By studying science's biggest discoverers and their broader traits, we uncover a unique portrait—a general profile of the greatest scientists in history. This is key for us to tackle our central puzzle: uncovering what consistently drives discoveries across science—and what is only relevant in certain discoveries. Strikingly, we find that interdisciplinary scientists, those with broader method training, are behind about half of all nobel-prize and major non-nobel discoveries over the same period. This highlights the importance of crossing scientific borders and combining methods across disciplines. We also unexpectedly find that younger, more motivated scientists are the ones behind our greatest advances: scientists over 50 made only 7% of all nobel-prize discoveries and 15% of non-nobel discoveries. Surprisingly, those over 60 made only 1% and 3%. And where do discoverers work? Most work at less-known institutions at the time of their discovery: scientists at top 50 ranked universities made up only one third of both nobel-prize and other major discoveries. This is important—it debunks the assumption that only top-tier institutions are where breakthroughs happen. We also dig deeper: exploring the geographic location, gender and wider country conditions of science's greatest discoverers.
So far, we have been unpacking how and when discoveries emerge. In this chapter, we dig deeper and fill in the gap: who makes them and where do they happen? Despite science profoundly shaping the course of human history, we know surprisingly little about who makes science's breakthrough advances. Understanding who D science's great discoverers are—the personal side of science—intrigues both scientists and the general public. Classic work on scientific discoverers goes back at least to Boleslaw Prus in 1873, Florian Znaniecki in 1923, Francis Galton's English men of science: their nature and nurture in 1874, and especially influential has been Harriet Zuckerman's Scientific elite: Nobel laureates in the United States in 1977 (Box 4.1). Researchers often explore a limited sample of discoverers, covering one time period, scientific field or country like the US or UK. While valuable, these snapshots do not allow us to draw broad, general insights about discoverers. A more comprehensive approach is needed—one that spans major discoverers across science, time periods and discoverers' broad traits to uncover the fuller picture. Typically, researchers studying the traits of scientists often also focus their lens on one factor—reflecting the broader trend in today's specialised scientific landscape that adopts a more narrow focus. Here we widen the lens to all nobel-prize and major non-nobel discoverers, exploring the broad range of demographic traits: their age, their education level, their interdisciplinary training, their gender, their country of residence, and their religious affiliation— all at the time of their discoveries. We also investigate their institutions—university ranking—and their broader social and economic features, including income per capita and population size of the country they lived in. By exploring this broader set of supporting factors, we find unique patterns in the background traits of science's eminent discoverers across fields and history—including the wider context they work in. We reveal how science's prominent discoverers have changed over time: they have shifted towards greater interdisciplinary education and method training—going against the common trend to specialise—and they are still making breakthroughs at a young age, though they are not as young as before. We also dig deeper to analyse what shapes discoveries by controlling for the common influencing factors and comparing how important they are (for interested readers, more details on the data are in the online Methods Appendix). Box 4.1 The sociologists of science Harriet Zuckerman and Robert Merton The American sociologist of science Harriet Zuckerman, while working at Columbia University, packed her bags and travelled throughout the US to interview Nobel laureates. She pioneered studying the traits of prominent scientists, asking them about their background, family and research. In her seminal book Scientific elite: Nobel laureates in the United States in 1977, she tells the story of how being 'a Nobel laureate is, for better or for worse, to be firmly placed in the scientific elite' and the history of science. She offers insight into the lives of Nobel laureates, 'as we follow the laureates from their social origins through their formal education and apprenticeships in the craft of science to 102 T HE ENGINE OF SCIENTIFIC DISCOVERY their major contributions at the research front' . One of Zuckerman's core arguments is that discovery is more of a collective effort than an individual enterprise—it is embedded in a social context, with the scientific elite made up of talented individuals influenced by institutions, education, social stratification and mobility. By exploring the experiences of scientists winning the Nobel prize, described as 'the ultimate scientific award' , she observes power, authority and influence in science's award system. Zuckerman argues that the path to these ultra-elite of science can be highly competitive and hierarchical, where only a few can achieve high success. Some Nobel laureates, she found, dedicated their lives to a single breakthrough, often sacrificing personal time and other ambitions along the way— with Nobel laureates achieving a kind of scientific immortality after they pass away. Yet Zuckerman's study only focused on a small sample of American Nobel laureates. In this chapter, we explore the broader spectrum of demographic traits for all nobel-prize and other major discoverers. Robert Merton—Zuckerman's main inspiration and later her collaborator— was another pioneering sociologist of science. He argues that discoveries take place within a scientific community with shared norms, values and institutions. Perhaps his most famous insight is the influential finding of the 'Matthew effect' in science—the idea that prominent scientists receive disproportionately more credit for their research than less prominent scientists with equally important contributions that often go unnoticed. The social structure of science generates a self-perpetuating cycle, where recognition breeds more recognition, solidifying the status of elite scientists. At 83, Merton married Zuckerman, with the duo leaving behind a large mark in the sociology of science. In short, sociologists of science focus on the interesting social conditions in which scientists work. They make valuable insights about science just like historians, scientists, psychologists and philosophers (Chapters 1–3). But while they explore the environment and traits surrounding discovery, they leave the key question unanswered: what actually drives science's breakthroughs—the common force we are unpacking as we progress through the book.
in broader methods to make breakthroughs With new tools driving new discoveries, what factors and traits can support scientists in getting their hands on and creating new tools to advance science? We begin by exploring education—a natural starting point in scientists' training. We find that 88% of science's major discoveries since 1600—when doctoral awards began to spread— have been made by researchers with a PhD at the time of their breakthrough. The figure rises to 96% for all nobel-prize discoveries (awarded since 1901). In other words, most discoverers are highly trained. As science has expanded, a paradox has D emerged: the more complex the world we study, the more sophisticated our tools must be to study the ever greater complexity. The two move closely in parallel. Today, to trigger new discoveries demands training in ever more advanced tools, from cutting-edge statistical methods to high-resolution electron microscopes, along with acquiring extensive bodies of knowledge. Truly mastering our best tools takes time, but is key. Over the history of science, dozens of great discoverers—including Faraday, Tesla and Dalton—completed at most only secondary schooling. Yet by mastering newly developed tools on their own, such as the galvanometer, electric generator and eudiometer, including mathematical methods, these scientists were able to spark groundbreaking discoveries. While universities offer structured training and greater access to cutting-edge methods, they have not always been necessary for achieving discoveries. Yet since the 18th century, discoverers have been more and more likely to hold a PhD and work as professors (as we see in Figure 4.1a). But what about interdisciplinarily education? Today, scientists typically specialise and work in one field—a common norm of science. Yet we find a unique pattern here: most nobel-prize discoveries—54%—have come from scientists with two or more degrees in different fields by the time of their breakthrough. The figure is 42% for major non-nobel discoveries over the same period—serving as an independent benchmark or control. Some fields rely on interdisciplinary training more than others: in medicine and biology, discoverers are most likely (69%) to receive degrees in multiple fields, compared to physics (39%), where specialisation is much more common (Figure 4.1d). Interdisciplinary education is on the rise, with over 70% of major discoveries since 2000 made by scientists who completed (at least) two different degrees. Simply put, discoverers are trained more broadly than their peers, and not necessarily more deeply. The National Research Council in the US argues that challenges at the frontiers of science can often require the intersection of disciplines. Deeply complex problems in both science and society can demand crossing scientific borders. So advances can arise at the edges and boundaries between fields. Scanning science's biggest discoveries, we find that innovation at times comes from combining methods across fields or harnessing a method from one field in another. Interdisciplinary training expands our toolkit: equipping us with skills in tools from different fields. It enables us to overcome rigid disciplinary constraints, merge seemingly unrelated methods in innovative ways and develop entirely new integrated methods. In short: it allows us to bridge gaps between disciplines by adopting a completely new approach to a complex problem that would otherwise remain isolated. Take the German Max Delbrück for example. Trained in physics at the University of Göttingen, he turned to biology in the 1930s, bringing with him cutting-edge tools from physics—including advanced statistical methods. With these unconventional tools, he was able to tackle unanswered questions in genetics and reveal that bacteria develop through mutations. His breakthrough 1943 paper Mutations of bacteria from virus sensitivity to virus resistance helped open molecular genetics. Similarly, the German Konrad Bloch's unique educational path— completing degrees in chemical engineering at the Technical University of Munich and biochemistry at Columbia University—gave him a special edge. It enabled him 59 3 21 3 14 14 5 9 23 23 27 18 29 9 9 15 21 6 944 21 57 251 27 65 21 30 67 100 0 20 40 60 80 100 Percentage of all discoverers Evolution of science: all major discoveries over time No formal edu. completed <1600 1600–1699 1700–1799 1800–1899 1900–1949 1950–1999 2000–2022 <1600 1600–1699 1700–1799 1800–1899 1900–1949 1950–1999 2000–2022 Secondary school Bachelors Masters PhD/Postdoc (MD) Professor 33 26 68 11 22 75 40 60 43 14 79 6 18 76 0 20 40 60 80 100 Percentage of all nobel-prize discoverers physics chemistry medicine/biol econ/social astronomy Contemporary science: all nobel-prize discoveries - by field Bachelors Masters PhD/Postdoc (MD) Professor 0.07 0.18 0.15 0.22 0.43 0.63 0.72 0 .2 .4 .6 .8 1 Percentage of all discoverers Evolution of science: all major discoveries over time Has 2+ degrees Has 2+ degrees 0.39 0.47 0.53 0.58 0.69 0 .2 .4 .6 .8 1 Percentage of all nobel-prize discoverers physics astronomy chemistry econ/social medicine/biol Contemporary science: all nobel-prize discoveries - by field Figure 4.1 A sharp rise in education and interdisciplinary training of discoverers—across time and fields The data show science's 761 major discoveries (including all nobel-prize discoveries) (Figure a and c)—and all 533 nobel-prize discoveries (Figure b and d). All professors have a PhD. A discoverer is defined as having interdisciplinary degrees if they earned two or more degrees in different fields. Universities were founded in the late 14th century, offering formal education and degrees since then. When combining all nobel-prize and other major discoveries over the same time period across these five fields in Figure d, we find that for example the share of discoverers with two or more degrees is 38%, 58%, 51%, 56% and 65%. D to apply new isotopic labelling methods to discover the mechanism and regulation of cholesterol. He uncovered how cholesterol and fatty acids are converted in our body. The British Frederick Sanger studied natural science, biochemistry and medicine at Cambridge, and combined his methodological training to apply new gel electrophoresis methods and pioneer one of the most influential techniques in the history of genetics: DNA sequencing. Not only have these powerful sequencing methods catalysed multiple discoveries, but Sanger himself also won two Nobel prizes for his breakthroughs. The Swedish Svante Pääbo first studied humanities, including history of science and then medicine at Uppsala University, before later pursuing postdoctoral studies in molecular biology and then becoming the director of the Max Planck Institute for Evolutionary Anthropology in Leipzig. His diverse background enabled leveraging the new DNA sequencing methods to explore ancient DNA, leading to the groundbreaking discovery of the Neanderthal genome and rewriting how we understand human evolution. The Canadian Donna Strickland, trained in engineering physics and optics at McMaster University, worked together with the French Gérard Mourou, trained in physics at the Sorbonne. Together, they employed new laser technology to develop a new breakthrough technique: the method of ultrashort high-intensity laser pulses. Their breakthrough method paved the way for laser eye surgery. The German Hermann von Helmholtz received a PhD in medicine and also studied physics and mathematics at the Humboldt University of Berlin. This allowed him to apply new mathematical principles and physical analysis that other physiologists did not. He could then make—at just 26—a foundational discovery that transformed part of physiology and physics: the principle of the conservation of energy. Then there is the British Rosalind Franklin, who studied physical chemistry at Cambridge and then turned to biology, ultimately applying x-ray crystallography methods developed in physics to capture the first remarkable image of the double-helix structure of DNA. History makes it clear: some of our greatest discoveries happen when we step outside our field and adopt powerful tools in other fields. Yet delayed discoveries are pervasive in science—often occurring when researchers are unaware of powerful tools outside their own field to tackle the very problems they seek to solve with less effective conventional tools (Chapter 1). There is a trade-off at play: as our knowledge and the methods we use to generate that knowledge expand over time, researchers have specialised into evernarrower fields. Yet making unexpected connections commonly relies on harnessing unexpected methods across domains. While the universal scholar is an ideal of the past, the small share of researchers who push the frontier are more likely to defy the trend towards specialisation and venture beyond their own domain. Although breakthrough research is often interdisciplinary, the very structure of scientific institutions—universities, academic journals and even prestigious awards like the Nobel prize—reinforces traditional disciplinary borders. To foster discoveries, we need to challenge and rethink these outdated disciplinary divisions and how we can promote and reward interdisciplinary research, including the 106 T HE ENGINE OF SCIENTIFIC DISCOVERY Nobel Prize. Independent of disciplines, we need to reward the best research. Beyond education and training, there is another closely linked factor here: researchers' age.