Lieber (1979) published a collection of many studies purporting to show a reliable lunar influence on various areas of human behaviour, although Rotton and Kelly (1985), using meta-analysis, have fiercely contested this claim. However whereas studies of social behaviour can be easily criticized for neglecting a variety of contributing variables, biochemical studies, like those of Rounds (1975), who has found a lunar periodicity in the concentration of neurotransmitter-like substances from human blood, are more difficult to refute.
One of the first researchers to study the effect of solar activity on mankind was a historian in Russia, Professor Aleksandr Chizhevsky (1897-1964), who is considered by many as the father of heliobiology. Chizhevsky’s main interest was sunspots, which he correlated with human activity.