A generation of Americans could enter the workforce with an unfounded sense of entitlement.

THE GIST:

- Data shows a significant increase in narcissism among Americans in the last 15 years.

- Narcissism is characterized by an unfounded and undeserved sense of entitlement.

- A generation of narcissists could lead to problems in the workplace, as well as risky business and political decisions.

Do you check yourself out in every reflective surface that crosses your path? Are you constantly using your cell phone to snap photos of yourself? Are you flexing your biceps while reading this sentence? You're not alone.

Narcissism has increased among Americans over the past 15 years, a joint study from San Diego State University (SDSU) and the University of South Alabama has concluded. The results suggest that the United States is poised to experience social problems as younger narcissists age and move into positions of power.

The study, led by SDSU psychologist Jean Twenge, sought to settle a hot debate in psychology over mixed results of studies examining the prevalence of narcissistic personality traits among tens of thousands of American college students. These traits include an unfounded sense of entitlement and overly high self-regard.

This rise could prove problematic for American society in the near future and may have already had a negative impact. Some researchers believe that the current credit bubble plaguing the American economy and the global financial crisis are the result of the risky decision-making and sense of entitlement associated with narcissism. As the number of narcissists grows, the United States could experience even more social problems as a result.

"What this means is that we have generations of people entering the workforce that expect special treatment, are demanding of others and making risky decisions -- ones that could be quite costly when you consider recent business fiascoes," says Amy Brunell, an Ohio State researcher unaffiliated with the study.

There is debate about the underlying causes of any increase in narcissism. Theories implicate parents, teachers and the media, which either allow or celebrate overly permissive attitudes toward individualism, and lead to an inflated and unwarranted sense of self-importance.

To measure narcissism, researchers use the narcissistic personality inventory (NPI), a standardized test with the 40 paired statements. Respondents must choose between, for example, "I insist upon getting the respect that is due me," or, "I usually get the respect I deserve." Scores are based on points attached to specific answers, so choosing the first statement over the second would add a point.

A score of 21 reflects high narcissism, says Twenge, who also points out that the NPI isn't intended to diagnose narcissistic personality disorder. Since it's a standardized test, however, it does serve as a useful tool for tracking changes in narcissism in a large population, which she's done in her recent study.

In their paper published in the January 2010 issue of the journal Social Psychology and Personality Science, Twenge and her colleague, social psychologist Joshua D. Foster, re-evaluated the data used in prior research. They found that a large sample from University of California at Davis, which has experienced less of an increase in narcissism prevalence than other campuses across the country, skewed the results.

Twenge and Foster also examined data nationwide among various age groups and data taken over 15 years at the University of South Alabama. They found the school's student population experienced a surge in narcissistic personality traits from 1994 to 2009. In 1994, 18 percent of students scored 21 or higher on the NPI. By 2009, 34 percent of students at South Alabama scored within that range.

"I'm extremely confident," Twenge told Discovery News of her findings. "I think these analyses end the debate completely. It's clear narcissism is rising."

However, others do not perceive these findings as making an open-and-shut case.

"So much depends on what is to be made of the NPI," said University of Notre Dame psychology department chair Daniel Lapsey, who is unaffiliated with the study. "This is like the old bromide about how to define intelligence; it's whatever is being measured by IQ tests."

Josh Clark is a writer for HowStuffWorks.com.