The Order of Innovation

What do Charles Darwin, Nicholas Copernicus and Frank J. Sulloway have in common? The first two, of course, were revolutionary scientific thinkers: Copernicus established that the Earth revolves around the sun; Darwin discovered natural selection. And Sulloway? He’s a historian of science at Massachusetts Institute of Technology who has discovered something else these two men — and indeed, most of the major innovators in science over the last 400 years — have in common: they were, like Sulloway himself, preceded in birth by at least one other sibling. Birth order, he found, is the most reliable indicator of whether a scientist will embrace or attack radical innovations.

The third of four children, Sulloway has spent 20 years — the last five of them in a windowless room in Cambridge, Massachusetts — searching out the birth order of 2,784 scientists who were on one side or the other of 28 scientific revolutions since the 16th century. With the aid of a grant from the MacArthur Foundation of Chicago, which subsidizes unusual research projects, he discovered that 23 of the 28 revolutions were led by later-borns.

You don’t have to be a social scientist to join this debate. Every parent and every child has an opinion about the effect of birth order — his, hers and all of ours. But social scientists want to measure effects. And in recent years, several prominent scholars have argued that the birth-order impact on behaviour is a myth. In 1983, for instance, Swiss psychologists Cecile Ernst and Jules Angst published Birth Order, a body in which they examined all existing studies on birth order and concluded that it has no effect on behaviour. And last year UCLA sociologist Judith Blake concluded that birth order is significant only in families with more than seven children.

Sulloway’s study took a different approach. He focused on the male-dominated world of science and the sole issue he measured was willingness to challenge established opinions. Those least likely to accept new theories were first-borns with younger siblings. They were followed by only children; next come later-born eldest sons (those with one or more older sisters and at least one younger brother) and later-born only sons. The most radical were younger sons with at least one older brother. “My data was drawn from all of the eminent people who spoke out on every innovation in science,” says Sulloway. “There’s no way that anyone can refute the data.”

Sulloway’s operative theory, which seems common-sensical enough, is that first-born children identify more readily with parental authority because, among other things, they are often put in charge of younger siblings. Through this identification, first-borns absorb the norms and values of society in ways that subsequent children do not. “The older child gets responsibility — he’s the company man," says University of Michigan psychologist Robert Zajonc, who agrees with Sulloway. In contrast, Zajonc observes, “the younger one tests the limits, tries to see what he can get away with.”

NOVEL PUZZLE: Applying the theory to scientific revolutionaries, however, can be tricky. Albert Einstein, a first-born, is clearly an exception to Sulloway’s rule, although he says that most of Einstein’s early acolytes were later-borns. But what of James Watson and Francis Crick, the pair, of first-borns who won the Nobel Prize for explaining the make-up of DNA? “Nobel Prizes are given for solving clever puzzles," says Sulloway — something first-borns are good at. First-borns, he contends, tackle officially sanctioned puzzles while later-borns flock to the untried and the novel.

Sulloway reckons Darwin (fifth among six children) as a true revolutionary because his theories were not only novel but considered heretical by Victorian churchmen. But Sigmund Freud, about whom Sulloway has written a book, proved too complicated to categorize according to birth order. The father of psychoanalysis was raised as a first-born because his two stepbrothers no longer lived at home when he was born. However, in his first three years, he was inseparable from his stepbrother’s son, who was actually older; for that period Freud was a later-born. Freud’s theory, too, is a hybrid: it is first-born oriented, says Sulloway, because it focuses on the parent-child relationship, but is later-born in its revolutionary impact.

Despite such conundrums, Harvard psychologist Jerome Kagan calls Sulloway’s work “a brilliant study” and especially useful in studying extremes in behaviour. Indeed, Sulloway interprets the Reformation as a conflict between first-borns supporting Rome and later-born Protestants. John Calvin was a younger child, he notes, and so were most of the Anabaptists. And Martin Luther, though first-born, fits the pattern, Sulloway insists, because he resented his strict father. The conclusion, though yet to be verified, is already evident: life is a struggle, as Darwin argued, between children and parental figures, as Freud suggested. It’s first-borns against everybody else, and the former are outnumbered.