lateness (when compared with Caucasian norms) and, as with Dennis' study, cradleboarding appears to make no difference.
All this sounds like a maturationist (sociobiologist?) reasserting his case, and that is of course a correct reading. In my opinion, the bulk of the evidence now available gives precious little reason to plan schedules for helping along normal growth patterns. Certainly there is ample evidence that practice and reinforcement make a difference, but perhaps working among the Indians of the Southwest chastens one's hubris, and engineering better humans--or even better sheep--seems a nasty thing even to contemplate. Any wise Navajo can tell you that Nature knows best, so let her be. Otherwise you may unloose more than you bargained for. I know that many of us in universities earn our keep by figuring out new ways to "therapize" and produce better humans, better crops and better sheep, so perhaps I had best end by wishing such efforts well. However, Mother Nature has been in the business of changing organisms a long time, and I should look to her for any real changes.
Dennis, W. The Hopi child. New York: Appleton-Century, 1940.
Freedman, D. G. Human infancy: An evolutionary perspective. Lawrence Erlbaum Associates, 1974.
Leiderman, P. H., Babu, B., Dagia, J., Kraemer, C., & Leiderman, G. F. "African infant precocity and some social influences in the first year". Nature ( London), 1973, 242, 247-249.
Warren, N. "African infant precocity". Psychological Bulletin, 1972, 78, 353-367.