The Reality-Based Community

 Born to regress

Ten years after it came out, I've finally got round to reading Frank Sulloway's Born to Rebel( (1996). This bestseller advanced the proposition that much of human character and history can be explained by birth order. Scientific, political and religious revolutionaries are, he claims, typically laterborns; their conservative opponents, firstborns. The different characters of the two groups can be explained in Darwinian term as the results of different optimal strategies for securing parental care. Firstborn children conform to parents' wishes, laterborn children do their own thing.

Sulloway worked on his own for two decades on the book, like his hero Charles Darwin, and clearly intended it as a magnum opus of the ev.psych. revolution. It has 280 pages of end-material, an overwhelming display of alpha-male scholarship. It's a monument, but a flawed one. After an initially favourable reception, the book ran into heavy and serious critical flak (see Townsend and Harris). SFIK it's neither been discredited nor accepted. So what should the non-specialist "common blogger" make of it?

We feel intuitively from our own experience that birth order matters in life, and are predisposed to believe. The book is certainly a good read as a group biography, "early lives of the scientists". But anecdotes, however numerous, can't prove Sulloway's thesis, and the rub must lie in the dry statistical models and tests.

There are two separate issues. The first is the historical examples: the leadership and reception of scientific revolutions, the Reformation, and the French Revolution, plus less systematic treatments of feminism and abolitionism. Sulloway, using his own massive biographical database, finds large birth-order effects here. For evolution before Darwin, the correlation of laterborn support vs. firstborn rejection runs to 0.43, the odds ratio (a measure which corrects for the greater numbers of laterborns) is 9.7 to 1. For the vote of members of the French Convention on the execution of Louis XVIII, the correlation is a more modest but non-trivial 0.15.

The critics score a few points here. The categorisation of mesmerism seems to change to improve the results. (And why, I would ask, leave out Marxism as a failed radical scientific revolution, or electromagnetism as as a successful one?) Gary Johnson, the angry editor of an academic journal Sulloway threatened with legal action (he's all for iconoclasm, but not against himself) got his own back by showing that Sulloway's table on Reformation martyrs is wrong. He also points out that birth orders in the sixteenth century are just too iffy for statistical analysis, except for royalty. The sort of detailed parish records on which family historians like Laslett rely were a result of the Reformation; and anyway families mutated then at Tinseltown rates as a result of maternal and child death and remarriage. However, all told the criticisms I've seen or can make myself or pretty minor. I give Sulloway the provisional win here, at least on science and the French Revolution. There really is something to be explained.

This isn't to defend all of Sulloway's biography and history. Some is superficial or cranky: W.E.B. du Bois is rated as more radical than the fanatical John Brown; the milksop Louis XVIII is described as a "tyrant"; French Revolutionary politicians are rated on a scale of "liberalism", which is like asking what sort of Tory Julius Caesar was; fascism, a doctrine with both radical and reactionary elements(cf. Gregor Strasser ) shares the bad-guy quadrant in a diagram with ultra-royalism (cf. Joseph de Maistre ), as forms of tough-minded conservatism; and, hilariously, Sulloway gives posthumous advice to Henry VIII on his poor choice of wives - he should have gone for more firstborns. The tone of these sections is triumphalist, even a mite obsessive. you wouldn't guess from the text that on his own model 85% of the variance in the vote of the French Convention on the king's execution wasn't due to birth order.

Sulloway next tries to show that these contextual effects result from general psychological effects of birth order, the second major issue raised by his book. However, the firm CW in psychology is that such effects are null or tiny, such as a single point of IQ. Sulloway went through the previous large book on this by Ernst and Angst (1983), whose survey of the literature found null results. He reanalysed their data, and came up with massive correlations - up to 0.4 for extraversion - in line with his large historical results.

This is where the critics (Modell, Harris and Townsend) score. Sulloway won't, it seems, share crucial data with these unsympathetic scholars; on their own they can't reproduce his findings; he didn't take adequate precautions against experimenter bias in his rating of individuals on various scales; he rejects the (unfavourable) self-testing results on flimsy grounds. A new psychological meta-analysis by Turkheimer and Waldron, and a big study by Reiss, confirm the null result (cited by Harris). Sulloway's own new study (cited in this defence) of sibling pairs comes up with correlations of 0.2 or less, and only 0.08 for "openness to experience", the crucial one for receptivity to scientific revolutions.

On a technical matter like this, I think (as I've said before) that non-experts have to go with the CW. At the theoretical level, the critics point out that ev.psych. predicts that birth order will produce strong differences in behaviour within the family, as we observe; but not necessarily outside, as the Darwinian interests of parents and children differ. Sulloway simply assumes that childhood differences in learned personality will carry over to adulthood, which isn't good enough. So on general differences, Sulloway hasn't made his point.

That leaves a big puzzle, which he can't address because he's stuck defending his weaker ground, and his critics won't because they think he's plain wrong. If birth order doesn't produce significant differences in general personality, where do the quite large specific historical patterns come from?

Here's my pennyworth. Let's just cut out the middle man of "general personality traits", as identified in psychologists' questionnaire tests. The resulting scales bear the same relation to character (how people are likely to behave) as IQ does to intelligence (how good people are at thinking). They measure some aspects of the concepts reliably and stably, but far from everything important we mean by the terms. The "personality" so measured may not count for very much in daily life, compared to contextual learned habits like the toddler's whine and the doctor's bedside manner. BTW, the meaning of persona has undergone a strange U-turn: initially the actor's mask of Greco-Roman theatre, and figuratively the masks we display in different roles, it has now become the stable core behind these roles. That is, if there is one. As Browning's cynical Venetian says in A Toccata of Galuppi's :

The soul doubtless is immortal - where a soul can be discerned.

Could learned childhood behaviour carry over more directly into adult lives? Judith Harris thinks not:

The reason birth order does not affect adult personality is that children discover at an early age that many of the behaviors they acquired at home are irrelevant or counterproductive in other social contexts. Fortunately, they are not compelled to retain these behaviors -- they are free to acquire new patterns of social behavior, better suited to their outside-the-family contexts.

This is oversell. Just how free are young people to slough off their familial skin? In practice they take many decisions in childhood and adolescence about schoolwork, interests, friends, sex, drugs, lawbreaking, that have long-range and sometimes irreversible effects. If you run away to go to sea, you can't swim back. Scientists in particular are often precocious, and develop their career interests early. All these choices are swayed by the family environment and its strong birth order ecology. Birth order plainly has considerable effects on what people become in life without going through allegedly fixed personality traits. Religious orientation also, though it can change throughout life, is largely settled in youth - this alone could account for much of the variance Sulloway detects in support for the Reformation.

This form of continuity doesn't fully explain how people behave in crises that arise only later in adulthood. Here's a pop-Adlerian idea. Most adult roles go along with stereotyped behaviours : dentists have to be conscientious and finicky whatever they did as toddlers on the potty. There's a kit of formal rules and informal rules of thumb that make up the tradecraft of professions and other roles. Much the same holds for status assignments: pecking orders in jobs and marriages change slowly. Science and politics are however neotenous : they prolong certain features of childhood, as humans prolong features of infant chimpanzees. Scientists carry over into their adult careers the childhood trait of curiosity; politicians the insecurity about status, and constant jockeying for it, of the schoolyard and family dinner-table. (Scientists minor in insecurity and politicians in curiosity).

Both professions have of course, like others, their tradecraft, which most of the time provides sensible guidance over the decisions to be made. But rarely there arise situations for which tradecraft offers no answer - revolutionary situations: a totally new theory that invalidates a longstanding CW and has upsetting social implications, the collapse of a political order such as monarchy. In such circumstances, as Sulloway says, people rely on "gut instinct". Where does this come from? The only psychic recourse may be to revert to the strategies of childhood and adolescence, especially for a group who are neotenous anyway and in that sense exceptionally bound to their past.

This mechanism is a hypothesis and looks testable, though not by me. It predicts that birth order will affect life-histories and adult roles a lot, but only small - though important - subsets of adult decisions within those roles, which seems plausible (see the mixed results reported by the neutrals Somit and Petersen here). It predicts that birth-order will matter for the reception of artistic revolutions like perspective, Impressionism, and Cubism/abstractionism, since artistic creativity is also neotenous. (Dig out Vasari, analyse the exhibitors in the 1863 Salon des Refusés vs, the establishment Salon). It may well be wrong. But you don't have to be much of a Freudian to think that one important dimension of character not captured by personality-trait scales is how far each of us is bound by memory.