If you think it's all about you, you're not alone. In fact, you're part of a trend that has been on the rise since the last century, according to a study by University of Michigan researchers.
Although self-interest was low in the 19th century, it rose steadily during the 20th century, peaking just after World War II and again in the 1970s, said William Chopik, a doctoral student in psychology who is the report's principal author. The paper appeared in the peer-reviewed journal Personality and Individual Differences.
Based on this study, Chopik said in an interview that prosperity and heightened competitiveness could explain why people may seem to be more self-centered.
This focus on self appeared to ebb during the recession that began in 2008, possibly reflecting greater concern for other people's needs, the study says.
Chopik and his collaborators, Deepti Joshi and Sara Konrath, gauged the state of the national ego by analyzing presidential State of the Union addresses from 1790 through 2012. They used Linguistic and Inquiry Word Count, a text-analysis software program to assess the prevalence of words related to self-interest.
Although Chopik said there was no way to factor in the presidents' self-interest, "people generally vote for politicians whose traits most resemble their own," he said, "and the content of presidential speeches might well reflect what politicians think the people want to hear."