Annual Rhythms in Man (IN: Handbook of Behavioral Neurobiology: Biological Rhythms v.4, edited by J Aschoff)

This international study spanning 5 continents between 1850 & 1980 concerns long term biorhythm trends in general mortality, suicides, and conception rates as influenced by sunshine, seasonal temperature & latitude. Other topics include growth rates in children & hormone levels. In conclusion there were definite seasonal rhthyms in suicides, conception rates & mortality. Deseasonilization may be related to industrialization, environmental and sociocultural factors that produce the phenomenon of “biological equator” evidenced by conception rates which are inversely correlated with socioeconomic status.