The words people use are like fingerprints that can reveal their relationships, honesty or their status in a group, according to research by University of Texas at Austin social psychologist James W. Pennebaker.
"Using computerized text analyses on hundreds of thousands of letters, poems, books, blogs, Tweets, conversations and other texts, it is possible to begin to read people's hearts and minds in ways they can't do themselves," says Pennebaker, the Liberal Arts Foundation Centennial Professor and Psychology Department chair. Pennebaker will publish his findings in his new book, "The Secret Life of Pronouns: What Our Words Say About Us" (Bloomsbury Press, August 2011), which is based on a large-scale research project that links natural language use to social and psychological processes.
Watch Dr. James Pennebaker discuss this topic and more in a Knowledge Matters five-part video series on YouTube.
Pennebaker uses his groundbreaking research in computational linguistics to analyze pronouns, articles, prepositions and a handful of other small function words.
"On their own, function words have very little meaning," Pennebaker says. "In English, there are fewer than 500 function words yet they account for more than half of the words we speak, hear and read every day. Who would have guessed that words like I, you, the, to, but, and and could say so much about us."
He even delves into politics, discovering why President Barack Obama uses "I" less than any modern president of the United States.
"People across the board think that Obama uses the word 'I' at incredibly high rates, but if you do an analysis he uses the word 'I' at lower rates than any modern president, by a lot," Pennebaker says.
Comparably, former Presidents Bill Clinton and George W. Bush used "I" at very high rates. Pennebaker finds that people who use "I" at higher rates tend to come across as more personal, warm and honest. While people who use "I" at lower rates come across as more self-confident. He attributes people thinking of Obama using "I" at such high rates, due to his self confidence and the misconception that confident people must use "I" all the time. He also finds that the highest status person in a relationship tends to use "I" the least, and the person who is the lowest status tends to use the word "I" the most.
In other studies, Pennebaker has helped to develop a linguistic lie detector. Within a group of college students, half were prompted to lie. According to the study, people who are telling the truth demonstrate a different language profile than those who are lying. Detection was much better than chance, with 67 percent accuracy.
"One way you can tell if people are telling the truth, they use 'I' more. They use more complex language," Pennebaker says. "People who are lying tend to not use the word 'I.' They are psychologically distancing themselves. And they also avoid markers of complexity such as conjunctions and prepositions."
Pennebaker applies some of his language findings to love. Using a speed dating study, he and his team looked at language style matching, which is how function words are being used at a comparable rate between a couple. According to the study, those people whose language styles most frequently matched were much more likely to go on a subsequent date.
"We did a better job predicting if they would go on a date than they did themselves," Pennebaker says. "This style-matching statistic tells use how the two are clicking with one another. The more likely they were to match in future text messages and instant messages, the more likely they were to still be dating several months later."