How would you measure the 'evolution' - that is to say, changes - in human culture and psychology over the last 200 years?
Psychologist Patricia Greenfield of the University of California, Los Angeles used the Google Ngram Viewer to examine the frequencies of specific words in a corpus of over 1,160,000 English-language books published in the United States between 1800 and 2000. At least it tells us how linguistics evolved.
The result, says Greenfield, is that people have shifted from rural environment to urban.
She has coined this hypothesis the "Theory of Social Change and Human Development" and believes that the usage of specific words waxes and wanes as a reflection of psychological adaptation to sociocultural change.