Analysis of words used in more than 1.5 million American and British books published between 1800 and 2000 has revealed how cultural values have changed in that time.
Researchers found an increase in the use of words like “choose” and “get” in the past two centuries while words like “obliged” and “give” decreased.
There was also an indication that people in modern society are more in touch with their emotions than they once were – the use of “feel” increased while “act” decreased.
The psychologists behind the study claim the shifts in language indicate how US and British society has grown more selfish as it has grown wealthier and more urban.
Professor Patricia Greenfield, a psychologist at the University of California Los Angeles who conducted the study, said: "This research shows that there has been a two century long historical shift toward individualistic psychological functioning.
"The currently discussed rise in individualism is not something recent but has been going on for centuries as we moved from a predominantly rural, low-tech society to a predominantly urban, high-tech society."
Professor Greenfield, whose work is published in the journal Psychological Science, used Google’s Ngram Viewer to count word frequencies in 1,160,000 books by US authors.
The software allows users to rapidly count the numbers of words in books.
These included novels, non-fiction titles and textbooks.
She then did the same with 350,000 books published in the UK before repeating the tests with synonyms for each target word.
“These replications indicate that the underlying concepts, not just word frequency, have been changing in importance over historical time,” said Professor Greenfield.
She found words that indicate a growing focus on the self, such as “child”, “unique”, “individual”, and “self”, all increased in use.
The use of words like “get” declined between 1940 and the 1960s before rising in the 1970s, perhaps reflected that cooperative feel and lower levels of self-interest during World War II and post war declined.
The importance of religion, obedience and social relationships also seemed to decline over the 200 year period, with words like "authority," "belong" and "pray” becoming less common.
Professor Greenfield is now hoping to replicate the work with books in Spanish, French, Russian and Chinese to look for global patterns in culture shift reflected in literature.
Gray, Richard. 2013. “Language in books shows how we have grown more selfish”. The Telegraph. Posted: August 7, 2013. Available online: http://www.telegraph.co.uk/culture/books/booknews/10229133/Language-in-books-shows-how-we-have-grown-more-selfish.html