Language is constantly evolving and is affected by a number of factors, including geography, ethnic background, and cultural values. Our words have indeed changed as we have become more reliant on technology and marked by growing urbanization.

A psychologist from University of California, Los Angeles (UCLA) wanted to find out exactly how language can be linked to cultural values, and how our societal development – and changing psychology – can be measured to some extent by the words we use.

Patricia Greenfield, author of the study and professor of psychology at UCLA, analyzed words used in over 1.5 million American and British books published between 1800 and 2000, and believes language shows how cultural values have developed and changed over 200 years.

Greenfield’s theoretical interest lies in the connection between culture and human development, according to her faculty biography.

In her study, she noted that words like “get,” “choose,” “feel,” and “individual” were used more frequently as the years went on. These words have more to do with materialism and the individualistic values that became more prevalent in the modern age, she noted.

"This research shows that there has been a two-century–long historical shift toward individualistic psychological functioning adapted to an urban environment and away from psychological functioning adapted to a rural environment," Greenfield said.

The use of words like “obliged,” “give,” “obedience,” and “pray” has decreased, the study notes, suggesting that the once-important values of obedience to authority and religion in everyday life have diminished. Frequency of the use of words like "act," "belong," and "authority" has also waned, in comparison to that of "child" and "unique," which has increased.

Greenfield measured the frequencies of these words in about 1,160,000 American books and about 350,000 books published in the UK. The similarities between the results for American books and for British books, Greenfield said, show a pattern that indicates "the underlying concepts, not just word frequencies, have been changing in importance over historical time."

Greenfield used a tool called Google Ngram Viewer, which measures and charts the frequency of words in millions of books. She notes that anyone can use this tool to replicate her results.