There is evidence that natural occurrences can impact human behavior whether it is the full moon that fills up emergency rooms or sunspots that are said to impact the economy.
Michael Mandeville wrote an interesting paper about the impact of sunspots on tumultuous times in our history. He writes:
A. L. Tchijevsky, a Russian professor of Astronomy and Biological Physics, noticed during World War I that particularly severe battles followed solar flares. Since the sunspots were in a peak period during 1916-17, no doubt the war and its various battles were heavily stimulated by the energies which are boiling off the Sun.
Intrigued by the connection of human behavior to solar physics, Tchijevsky constructed an “Index of Mass Human Excitability”. He compiled the histories of 72 countries from 500 BC to 1922 AD to provide a strong database to articulate his correlations. After rating the most significant events, Tchijevsky found that fully 80% of the most significant human events, mostly related to war and violence, occurred during the 5 years or so of maximum sunspot activity.
Is it possible to ascertain historical times of tumult by using sun spots? Read more here.