The journal Economics and Human Biology has an obituary (in press) describing the life of James M. Tanner, and his singular contributions to the development of the study of human growth. In his memorial, Roderick Floud quotes David Barker as saying “Jim was the God” of growth studies.
I had missed news of Tanner’s passing, which occurred in August, and was sad to learn of it. His work has been invaluable to many people, including my own teaching and research, from formulating growth charts to a comparative look at how people grow in different parts of the world. But it’s important to reflect not just on his contributions to science, but also the person behind them. One gets a sense of his compassion from the way he referred to childhood growth as a mirror for “the material and moral condition” of a society (1986: 3). Floud quotes an oft-cited passage by Tanner:
A child’s growth rate reflects, better than any other single index, his state of health and nutrition, and often indeed his psychological situation also. Similarly, the average value of children’s heights and weights reflect accurately the state of a nation’s public health and the average nutritional status of its citizens. . . . Thus a well- designed growth study is a powerful tool with which to monitor the health of a population, or to pinpoint subgroups of a population whose share in economic or social benefits is less than it might be.”
Eveleth, Phyllis B. and Tanner, James M. 1990. Worldwide Variation in Human Growth (second edition). Cambridge: Cambridge University Press.
Tanner, James M. 1986. Growth as a mirror for the conditions of society: secular trends and class distinctions. In Human Growth: A Multidisciplinary Review. Arto Demirjian and Micheline Brault Dubuc, eds. Pp. 3-34. London: Taylor and Francis.
Tanner, James M. 1990. Fetus into Man: Physical Growth from Conception to Maturity. Cambridge, MA: Harvard University Press.
On the surface, it may not be so clear where war, health, and evolution intersect. From the perspective of biological anthropology, many have called for a holistic, transdisciplinary approach to human biology and health which considers the environment as the totality of its evolutionary, ecological, and social components, including social inequality (Little and Haas 1989; Thomas et al. 1989; Wiley 2004).
Girl in Darfur refugee camp (source: Colin Finlay)
More than a decade ago, Leatherman and Goodman (1998) suggested that biological anthropologists put more effort toward better understanding what they termed the ‘biology of poverty.’ In this sense, poverty is an ‘environment’ that may induce consistent, but obviously varying, biological responses depending upon local circumstances. Similarly, war can be conceived as a biological environment. At least in the short term from an evolutionary point of view, wartime conditions may be as biologically challenging as some of the classic ecologically extreme environments faced by humans (circumpolar, tropical, high-altitude, desert, etc.) (Clarkin 2010).
At the population level, childhood growth is often seen as a marker of health and the quality of the environment. When populations get taller in a few generations, this is likely due to some improvement in local conditions (better nutrition, less infection, cleaner water supply, etc.). Conversely, when linear growth declines, it is usually because local conditions (ecological, economic, political) have deteriorated. Two recent working papers illustrate how this pattern applies to war conditions.
As social animals, we need to be around others. Virtually everything we do is social – trade, eating meals, watching sports in stadiums or movies in theaters, religious services, education, the internet, etc. Even war is a social activity. No human being on the planet is completely self-sufficient. Being social is more than utilitarian, however; it is also biologically and psychologically necessary. For example, one of the most severe forms of punishment in prisons is solitary confinement.
A recent study on child obesity by researchers at Harvard has received a good deal of media attention lately. In the NY Times, a synopsis of the study was one of the most emailed articles in the country (“Baby Fat May Not Be So Cute After All,” March 22). The key sentence from that article:
“More and more evidence points to pivotal events very early in life — during the toddler years, infancy and even before birth, in the womb — that can set young children on an obesity trajectory that is hard to alter by the time they’re in kindergarten.”
Harvard researchers are reporting in the journal Obstetrics & Gynecology that the average birth weight in the U.S. has actually dropped over the past 15 years. The study looked at more than 36 million full-term births between 1990 and 2005. After controlling for confounding variables, it was found that birth weight had decreased by 52 grams. This trend ran counter to that found previously, which was that birth weights had been steadily increasing over the last century. A secondary analysis suggested that the drop was not due to a change in maternal demographics, as the trend was also found in a subset of white, well-educated non-smoking women as well.