Height cycles in the 18th and 19th centuries.

Spectral analysis of the physical stature of Americans and Europeans in the 18th and 19th centuries reveals a cyclical structure similar to the traditional view of the business cycle: a longer cycle with a length of 7-10 years, and a shorter cycle with a length of 3-5 years. The correlation between height cycles and cycles of economic variables such as grain prices indicates an influence of economic cycles on physical stature. The phase shift between the cycles indicates that economic conditions are especially important for growth in infancy. In part, this result is due to a cumulative effect: born into a recessionary period, a child is likely to face several cyclical downturns during the growing years.