JB: Where are you headed in your future research?

SULLOWAY: I consider the findings in Born to Rebel to be just a preliminary outline of the many problems that we are now facing trying to understand personality development. Also, the book provides only a bare introduction to understanding how we can apply Darwinian theory to understanding all of the learned adaptations of childhood. Adaptations in childhood are not just random; they occur for a purpose, and this purpose is to get one's genes into the next generation. There is a whole class of potential future studies that can be done on these issues. These studies are going to require an even stronger interface between evolutionary biology and developmental psychology. I believe this area of research is going to be a very exciting one for the future.

My own future research is going to be more psychological than historical, so that I can answer some of the questions that I could not answer using historical data. In Born to Rebel I developed statistical models that combined the predictive power of birth order, parent-offspring conflict, temperament, and other variables in explaining what historical figures actually did during times of radical social and intellectual change. We can do a far better job in this regard by working with living individuals because we can ask specific questions about developmental history—for example, the nature of strategies employed in dealing with siblings, and to what extent these strategies (and associated personality characteristics) predict adult behavior. The jump to research on living subjects is a bit like moving from a 19th-century locomotive to a 20th-century jet in terms of the sophistication that one can hopefully achieve, and few of these kinds of studies have been done.

In order to achieve the kind of understanding of families that we need to have, we require studies in which all members of the family are studied simultaneously. When psychologists wanted to study an influence such as birth order in the past, they collected data on firstborns and laterborns selected from different families. We miss too much with this approach. I'll give you an example of why we want to study individuals growing up in the same family. Suppose you are a firstborn. Your usual strategy for dominating your younger siblings would be to act like a tough-minded Clint Eastwood (who, incidentally, is a firstborn like most of the other Hollywood macho types—John Wayne, Sylvester Stallone, Bruce Willis, and all of the actors who have played "James Bond"). But suppose a firstborn happens to be shy. Shy people do not generally chose to employ strong-arm tactics—they tend to be retiring and physically timid. And this shy behavioral disposition undermines their ability to occupy the typical firstborn niche. So a shy firstborn is likely to develop a different set of strategies for dealing with siblings. Such individuals might try to keep younger siblings in their place by being moody, or by giving younger siblings who have offended them the cold shoulder. There are many other strategies that people can employ in place of strong-armed tactics. The minute one opts for one set of strategies over another, the door is opened for a younger sibling to adopt some of the strategies that are not being employed. If one is comparing two individuals from different families, one misses these kinds of —coadaptations.— It should be kept in mind that personality development takes place on a kind of chess board. The moves that one family member makes are dictated by the moves that have already been made by other family members on the same board. Extraordinary as it may seem, very few studies have been done of personality development from this perspective. From an intuitive psychological point of view—but also from a Darwinian point of view—this is the best way to study human development.

JB: Will these studies be conducted in Western countries?

SULLOWAY: Since most psychologists live in the Western world, this is where the bulk of these studies will be done. But since psychologists always love to see cross-cultural replications, we will begin to see studies done in places such as Africa or South East Asia. Eventually such studies will be done around the world, and we should definitely expect some interesting twists on the story of human development as we go from one culture to another.

JB: Last words?

SULLOWAY: I have to say that I had no idea what I was getting into when I stumbled onto the project that culminated in Born to Rebel. Looking back 26 years later, it has been one of the most interesting things I possibly could have done. I have never gotten bored trying to understand what makes human beings tick. And to have recognized, two decades into the project, that Darwinian theory was a major player in understanding individual human differences was an exciting insight as well. The mysteries of human development have been a wonderful subject to devote my life to, and I hope to stay interested in these problems, and to continue to make progress in trying to resolve them.