The linguist G. K. Zipf discovered that the frequencies of words in a language are distributed according to a power-law. They fall into an L-shaped curve with a tall spine containing a large number of rare words (like deliquesce, kankedort, and apotropaic) and a long tail containing a small number of extremely common ones (like the, be, and of). In any corpus of language, a small number of the most common words account for a large proportion of word tokens. 

The physicist and psychologist Lewis F. Richardson discovered that the frequencies of wars between 1815 and 1952 are distributed according to a power-law.