Kuzawa and his collaborators applied the same framework in this study and found evidence that male characteristics -- such as height, muscle mass and testosterone levels as opposed to disease characteristics -- also relate back to early life developmental plasticity.
"Another way to look at it is that the differences between the sexes are not hard wired, but are responsive to the environment, and in particular to nutrition," Kuzawa said.
Testosterone has long been known to increase muscle mass and puts a person on a higher growth trajectory to be taller. The Northwestern study suggests that the age of puberty also is influenced by events in the first six months of life.
The study, which was funded by the National Science Foundation and the Wenner Gren Foundation, was conducted among a group of 770 Filipino males aged 20 to 22 who have been followed their entire lives. Since 1983 a team of researchers in the United States and the Philippines (including Kuzawa for about the last 10 years) has been working to understand how early life nutrition influences adult health, such as risk for cardiovascular disease and diabetes.
"Rapid Weight Gain After Birth Predicts Life History and Reproductive Strategy in Filipino Males" was published Sept. 13 in the Proceedings of the National Academy of Sciences. The study's co-authors are Thomas W. McDade, associate professor of anthropology, Northwestern University, Linda S. Adair, University of North Carolina at Chapel Hill, and Nanette Lee, University of San Carlos of the Office of Population Studies in Cebu City, Philippin
|Contact: Hilary Hurd Anyaso|