The Marching Order : Frank Sulloway has spent the last 26 years working on his book about birth order and its effects on personality and behavior. But some experts say it’s bunk.

We’re born to the same parents, raised in the same house with the same values. So what makes one brother a criminal and the other a priest? Why does one sister pierce her tongue and dance the night away while the other stays home doing needlepoint on the plastic-covered couch?

So far, neither nature nor nurture has provided a completely satisfactory explanation. Over the past three decades, another theory--birth order--has crept into the breach, captivating the pop psych audience but dividing academic researchers. Now, as scientific revelations continue to pinpoint genetic roots for many personality traits, a controversial book is affirming the effects of birth order not merely on individual behavior but also on the whole of human history.

“Born to Rebel” (Pantheon Books, 1996) has hit a nerve, tapping into the public’s fascination with family position as a way of understanding ourselves. While proponents have applied it to everything from parenting to sales techniques, critics say birth order has about as much validity as astrology.

Now in its fourth printing, the book has sold more than 50,000 copies and hit the bestseller lists in Boston and San Francisco despite a technical approach by author Frank Sulloway, a visiting scholar at the Massachusetts Institute of Technology. Sulloway has spent the last 26 years researching and honing his 368-page argument, which includes an additional 285 pages of academic appendixes.

“It’s really a book about family dynamics,” Sulloway said in a telephone interview from his home in Cambridge, Mass. In his view, siblings carve out distinct niches for themselves in the family through a Darwinian struggle for their parents’ love and attention. In studying 5,500 historical biographies, he found that other family factors influenced their behavior (he controlled for an exhaustive 256 variables), but nothing else, he said, “packs the wallop” of birth order.

According to Sulloway, firstborns, secure in their position and remaining close to parental values, tend to be the most conservative. Later-borns, who must develop an array of strategies to distinguish themselves, tend to be more creative, sympathetic to underdogs and rebellious.

Praised for his “interesting melding” of scientific method and historical anecdote, Sulloway has also been criticized as a talented amateur with an overly proud and unscientific “attitude.”

Writing in the New Republic, Alan Wolfe called Sulloway “immodest, bombastic, ambitious, combative, defensive”--qualities that are the opposite of those needed for scientific testing. Wolfe also contends that Sulloway was culturally biased by assuming all families throughout history have had the same structure.

Sulloway said he’s “not too bothered” by the critics, whom he described as people with axes to grind who were more than likely “born angry.”

Back in 1970 when Sulloway was a graduate student at Harvard University, birth order was a fashionable subject among psychology students. For many, the basic idea, advanced by psychologist Alfred Adler in the early 20th century, was seductively simple and practically self-evident: Your place in the family determines your personality.

Few can deny that firstborns bask in the full sun of their parents’ attention, get more photographs taken, have more baby books filled out. But more is also expected of them and, as the popular theory goes, they become authoritarian, perfectionist, hard-driving and responsible.

Last-borns, the babies of the family, can be pampered and spoiled. They tend to be more easy going and popular, and take more risks, but can remain insecure and vulnerable.

Those in the middle, it is said, feel squeezed out of any privileged or significant position and may either learn to become negotiators or remain troubled finding their own place.

Skeptical at first, Sulloway said he was intrigued by one of his professor’s pet theories, namely that the reason Charles Darwin supported evolution and Charles Lyell, a 19th century naturalist, opposed it was that Darwin was a later-born and Lyell a firstborn. He decided to seek proof. “I have a penchant for wanting to test things,” Sulloway explained.

But as Sulloway was plugging away, other scientists were busy debunking birth order. In 1983, two Swiss psychiatrists, Drs. Jules Angst and Cecile Ernst, published a survey of all the birth order research from 1946 to 1980. Citing “methodological fallacies,” they concluded that birth order influences on personality and IQ had been widely overrated. The finding was powerful and, Sulloway said, “It shut down respect for the field. People concluded most birth order research was just bunk.”

Meanwhile, pop psychologists like Kevin Leman picked up the theory and ran with it--all the way to the bank.

Leman, a Tucson-based psychologist and talk show host, has published four birth order books, including “The Birth Order Book” (Dell, 1985), which offers advice on marriage, career choices and parenting techniques suited to each child’s niche. His latest book, “Winning the Rat Race Without Becoming a Rat” (Thomas Nelson, 1996), advises salespeople how to use their birth order and the birth order of customers and employees to “get to the top and stay there.”

“The babies of the family are your best sales people,” he said in an interview. “They could sell dead rats for a living. They make a living knowing how to get around people. They have had to. They’re always looking up.”

When he first heard about birth order as a graduate student in 1966 at the University of Arizona, Leman recalled, “I never saw anything so descriptive of personality. All I could think of was my [firstborn] sister Sally. When I go to her home in Jamestown, N.Y., she always has a clear vinyl runner. She ties bows on garbage bags. She puts newspaper under the cuckoo clock. Her kids were color-coordinated from birth on up.”

Leman said he was a typical last-born, a showoff and class clown who was “written off early in life.” His brother was a “rough-and-tumble” middle child but because he was the first boy, also had firstborn traits, he said. “In most families, there are two firstborns.”

Birth order theory is laced with such permutations, depending on the number, gender and spacing of children. If more than five years separate children, for instance, subgroups of birth order may form, many psychologists believe. One child’s position may be seized by another child under certain circumstances, such as an older child’s death or conflict with parents. Children can either capitalize on an assigned role or resist it, depending on inborn temperaments such as shyness.

Even Sulloway admitted, “You can find an exception to any statement about birth order.”

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Some psychologists still view birth order as one of the attractive quick-fix theories that appeal to so many Americans.

Concerned over the public’s fascination with birth order, some also caution parents and grandparents that such labels can interfere with children’s natural development. “Labeling a child as very neat is not such a bad label, but it puts a lot of pressure on someone to be like that all the time and doesn’t give them the flexibility and freedom to be other ways,” said Laura L. Mee, a child psychologist at Eggleston Children’s Hospital in Atlanta.

But at least one researcher said the pop psychologists are intuitively on target even if their theories are naive and lack empirical support. “I think people who have denied birth order effects are, too, very often naive,” said Robert Zajonc, professor of psychology at Stanford University.

Zajonc said he hopes to settle the dispute later this year when he publishes the results of a long-term study of 800,000 SAT scores proving that firstborns indeed have higher IQs. Not only do they have more time with the adult parents, but they also gain intellectually from serving as teachers to their younger siblings, he said.

One of the problems with past studies--even Ernst and Angst’s study of studies--is that they sought correlations between birth order and certain traits for individuals, Zajonc said. “These differences only emerge in the aggregate, when thousands and thousands are studied,” he said. For example, the fact that his younger sister is much smarter than he is, Zajonc said, doesn’t mean birth order has no effect on IQ.

What’s more, he said testing needs to be done at the same age because effects of birth order are rarely apparent in children younger than 11. “When you ignore the age of testing, it looks like there are no correlations at all and people throw up their arms in the air and say there’s nothing there.”

Zajonc believes Sulloway has been unfairly attacked--mostly by historians of science. “They don’t like to see the history of science depending on factors of personality. They like to see the history of science progressing intellectually by ideas. One of the things they would not like to do is give up the history of science to psychologists.”

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In addition to affirming the effects of birth order, Sulloway said he hopes his book pioneers a new kind of scholarship, a labor-intensive use of empirical testing to understand human behavior in history.

He said he plans to continue his testing and update the book when appropriate. Perhaps that’s inevitable since, with two older brothers and one much younger half brother, he is a “functional” last-born.

“People who test are people who challenge authority,” he said. Sulloway denied that his own birth order had anything to do with his conclusions, although after all this time, he admitted to some emotional involvement with his work.

“It’s not a book in which one group comes out on top. Firstborns win more Nobel Prizes, they’re good at puzzle solving and have higher IQs,” he said.

“But I confess this: I have a soft spot in my heart for later-borns in history. They freed the slaves and got rid of dictators. Tyrants are more likely to be firstborns. All of us, hopefully, hate tyrants.”

Twenty years from now, he said he hoped people would say, “He was basically right. And the others were on the wrong track.”

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The Marching Order

Firstborn

Lucy (Linus Van Pelt’s older sister)

A typically bossy, domineering firstborn.

Catherine Parr

The sixth wife of Henry VIII, she was the only firstborn and the only one to outlive him. The wives who lost their heads tended to be later-borns and outspoken.

Courtney Love

A punk provocateur, she nonetheless calls herself, a la author Frank Sulloway, a “classic firstborn--very conservative, a real traditionalist.”

Supreme Court Justices

Voting records analyzed by Sulloway since 1946 show that the 12 firstborn justices voted more conservatively than the 11 middle-borns, who in turn were more conservative than the nine last-borns.

Others

Bill Clinton, Mao Tse Tung, Phyllis Schlafly, Ayn Rand, George Washington, Margaret Mead.

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Last-Born

Ross Perot

Spoiled, popular, risk-taking and insecure are some traits of this group. Any resemblance here?

Benjamin Franklin

The youngest son of the youngest son for five generations; a rebel who earned fame as printer, scientist, statesman. Not allowed to draft Declaration of Independence “for fear he would conceal a joke in the middle of it.”

Others

Ronald Reagan, John Candy, George Carlin, Eddie Murphy, Billy Crystal, Katie Couric, Goldie Hawn, Mahatma Gandhi.

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Middle-Born

Jan Brady

Stuck in the middle between beautiful perfect firstborn Marcia and cute lovable last-born Cindy.

Richard Nixon

A middle child who became known for diplomacy in foreign affairs, among other things.

Others

Donald Trump, George Bush, Fidel Castro, Barbara Walters, Michael J. Fox.

Martin Luther King Jr.

The second of three children, he often intervened on behalf of his older sister, who was teased to the point of tears by their younger brother Arthur.

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Only Children

They can have characteristics of firstborns, (perfectionist, reliable, conscientious, well-organized, critical, serious, scholarly) but sometimes feel inferior, shooting for parents’ high standards.

Elvis Presley, Leonardo da Vinci, Franklin D. Roosevelt, Nancy Reagan, Ted Koppel, Brooke Shields, T. Boone Pickens, Joe Montana, Lucille Ball.