Historian Links Birth Order To Innovation
Charles Darwin, whose theory of natural selection overturned traditional views of the creation and evolution
of life, was the fifth child of six and Alfred Russell Wallace, the co-discoverer of the theory, was the last of six children.
But George Cuvier, an upholder of the creationist view, was the first child of four, as was Louis Agassiz, another opponent
Frank Sulloway, a historian of science who proposes that birth order makes a startling difference in the progress
of science, is himself the third of four children.
Dr. Sulloway cites the roles played by these and thousands of other scientists as prime evidence for a provocative
theory: researchers who challenge established views tend to be born later in their families while those who support the status
quo tend to be firstborns.
His proposal comes at a time when the idea that birth order makes any difference in behavior is under fierce
attack by social scientists. Despite the attacks, the birth order concept is an idea that will not die. Dr. Sulloway's study
is perhaps the most elaborate among the continuing efforts of dozens of researchers to find a link between birth order and
such things as managerial ability, drug abuse, criminality, and teen-age pregnancies. In 1988 and 1989 there were 45 scientific
reports on birth order, more than a third of which found it had no effect.
Dr. Sulloway, who is now a visiting scholar at the Massachusetts Institute of Technology, may be living proof
of his own theory. His first major work, ''Freud: The Mind of a Biologist,'' in 1979 scandalized orthodox psychoanalysts by
saying that Freud borrowed much of his theory from the biological thinking of the period.
Now Dr. Sulloway has done it again. After years of research, he has proposed that firstborns are more likely
to defend current theories and those born later are more likely to attack them. In the process, he is resurrecting the notion
that birth order can to some degree steer personality in later life, an idea that most social scientists have come to reject.
''I'm skeptical of any reported effect for birth order,'' said Judith Blake, a sociologist at the University
of California at Los Angeles. '' People get excited by the idea of birth order, but when you look at it scientifically, it
Support From Some Psychologists
But Dr. Sulloway's studies are finding support among some eminent psychologists.
''He has solid data,'' said Robert Zajonc, a psychologist at the University of Michigan. ''I can't argue with
what he's found.'' Jerome Kagan, a psychologist at Harvard, called Dr. Sulloway's work ''the most extraordinary birth-order
effect I've ever seen.''
Dr. Sulloway, a recipient of a MacArthur Foundation award, came to his view through the diligence of 19 years'
labor and the assistance of scores of colleagues. For the last five of those years he squirreled himself away in a small,
windowless office at Harvard.
There Dr. Sulloway finished his analysis of 2,784 participants in 28 major scientific controversies in the
last 400 years. He included the 20 or so great revolutions of science, as well as some obscure controversies like the debate
over phrenology. The main criterion was whether enough remained in the historical record about the scientific debate to evaluate
the main participants.
Though he largely worked alone, he turned to nearly a hundred colleagues in the history of science, asking
them to nominate the scientists to be studied. The historians judged the stands each scientist took, as well as as the scientist's
political and religious views, family size and 40 other variables.
Birth Order and Innovation
Birth order was by far the strongest predictor of whether a scientist would accept or reject radically innovative
Of the 28 scientific revolutions, 23 were led by later borns. And in those with a firstborn as the leader
- Einstein and Newton, for example - their prominent allies were for the most part later borns.
Of the 2,784 participants studied, 37 were siblings who joined in the same scientific controversy. Of the
7 firstborns among them, 6 opposed the radical new ideas being debated. And of the 30 younger siblings of these firstborns,
27 were supporters of the innovation.
''The overall probability that a firstborn will suppport a scientific revolution is 34 percent; the odds that
a later born will do so are almost double: 64 percent,'' Dr. Sulloway said.
Dr. Sulloway reported the findings at the meeting of the American Association for the Advancement of Science
in February. Since he announced his findings, they have sparked continuing controversy even though they are yet to be published.
Reformers Likely to Be Born Later
In studies currently underway, Dr. Sulloway is finding the same birth order effect at work among social reformers
in historical movements like the abolition of slavery, civil rights, union organizing and women's rights.
''Later borns have a greater tendency to be reformers of all kinds,'' he said. ''For instance, the Protestant
Reformation largely split noble families by birth order.''
Dr. Sulloway explains the conservatism of firstborns by their relationship with their parents. ''As the eldest,
firstborns identify more closely with parents, and through them, with other authorities,'' he said. ''And they play the role
of parental surrogate to later children. They end up more conforming, conscientious, and conventional than later siblings.''
On the other hand, he said, later siblings tend to rebel against the firstborn's authority.
''For the firstborn, it's taking over for daddy, being a responsible member of the establishment,'' said Dr.
Zajonc. ''The younger ones grow up testing the limits, seeing what they can get away with.''
Despite a handful of influential defenders like Dr. Zajonc, Dr. Sulloway's theory is encountering a scientific
attitude that is skeptical of any birth order studies.
Family Size Seen as More Important
Last July, Dr. Blake published data in Science showing that for 113,000 people, the order of birth made no
difference in how far they went in school or how intelligent they were, despite earlier studies suggesting that firstborns
had an advantage.
''What matters instead,'' Dr. Blake said, ''is how large a family one comes from. What had seemed to be birth
order effects were artifacts. The real effect was due to parents' characteristics - the lower the social class and the less
educated the parents, the bigger the family.''
Whatever small differences had been found, Dr. Blake said, were due to the statistical weight of those born
seventh or later in families of poorer, less educated parents. Thus what seems to be an effect of birth order actually reflects
the family's economic and educational status, Dr. Blake said.
Dr. Blake's attack on birth order theory came on the heels of a 1983 book ''Birth Order,'' written by two
Swiss psychologists, Cecile Ernst and Jules Angst. A massive review of scientific studies, their work came to much the same
conclusions as Dr. Blake: on closer scrutiny, virtually all the hundreds of findings about birth order are due to other factors
like family size and economic status.
That includes the well-known findings, first proposed by Sir Francis Galton in 1874, that firstborns tend
to rise to positions of eminence more than later borns.
But Mr. Sulloway used statistical methods that corrected for the influence of family size. He also pointed
out that in their devastating critique of the birth order literature, Dr. Ernst and Dr. Angst found that one of the few ideas
supported by well-done studies is that firstborns are more accepting of parental authority and identify more with their values
than do those born later.
But, they noted, that has been shown only in studies with children and adolescents. Dr. Sulloway's is among
the first to show it with adults.
Birth Order and Personality
Dr. Blake could not comment directly on Dr. Sulloway's study. ''I haven't seen his data,'' she said. But,
she added that in a project now underway, she is analyzing data from almost 10,000 people to see if there is any relationship
between any personality trait and birth order.
''I don't get anything for either birth order or family size on any personality variable, including conformity,
sociability, anxiety and assertiveness,'' Dr. Blake said.
But some other recent findings fit well with Dr. Sulloway's theory. For instance, a study of 835 accountants
published in 1988 found that firstborns scored higher than those born later on tests of dominance and leadership ability,
of wanting to make a good impression and of achievement through conformity rather than through independence.
''The firstborns are more conformist because of their parents' expectations,'' said Arthur Bedeian, a professor
of management at Louisiana State University and one of those who conducted the study. ''They're put in a leadership position
from their early years, standing in for their parents in caring for the younger ones. The younger children, though, are freer
to be independent, to define themselves by other standards.''
Some recent studies, like Dr. Sulloway's, are generally designed to overcome the objections of Dr. Blake and
other critics. From some of the studies have come entirely new twists to the birth order concept.
For example, data from 7,018 children rated from birth to age seven showed that there was a direct relationship
between birth position and the child's activity level. Firstborns were the most active, second children more active than third
and so on.
''The finding surprised us,'' said Dr. Judith Chipperfield, a psychologist at the University of Manitoba and
one of those who did the study. ''Children who are more active early in life learn more from their environment; they're more
Another new perspective holds that it is not birth order at play as much as the age of the child's mother.
That position is taken by Stanley Coren, a neuropsychologist at St. Lawrence University in British Columbia. Noting that later
born children have a greater chance than firstborns of being left-handed, Dr. Coren has proposed that is due to the mother's
Children born to mothers in their early 30's are a third again more likely to be left-handed than children
born to mothers between 17 and 24 years of age, while children born to mothers older than 40 are more than twice as likely
to be left-handed.
The finding is of significance, Dr. Coren said, because about half of left-handed children have neurological
indicators of problems in brain development, like dyslexia and other difficulties in problem-solving. Left-handed children
also have more auto-immune diseases like allergies.
For her part, Dr. Blake remains skeptical of all the birth-order findings. ''I can't think of a domain where
there's a genuine birth-order effect. Every time you look hard at it, it turns out to be an artifact, usually of family size.''
Other researchers feel that birth order still has effects, though not nearly so widespread as had once been
thought. ''The psychology of birth order has a tiny effect, if any, on things like intelligence,'' said Dr. Zajonc. ''But
it may be far more important in areas of life such as upholding traditional values and conventions or questioning them.''