By Joanna Chau

Millennials, the generation of young Americans born after 1982, may not be the caring, socially conscious environmentalists some have portrayed them to be, according to a study described in the new issue of the Journal of Personality and Social Psychology.

The study, which compares the traits of young people in high school and entering college today with those of baby boomers and Gen X’ers at the same age from 1966 to 2009, shows an increasing trend of valuing money, image, and fame more than inherent principles like self-acceptance, affiliation, and community. “The results generally support the ‘Generation Me’ view of generational differences rather than the ‘Generation We,'” the study’s authors write in a report published today, “Generational Differences in Young Adults’ Life Goals, Concern for Others, and Civic Orientation.”

For example, college students in 1971 ranked the importance of being very well off financially No. 8 in their life goals, but since 1989, they have consistently placed it at the top of the list.

The study—by Jean M. Twenge, a professor at San Diego State University; Elise C. Freeman, a graduate research associate at the same university; and W. Keith Campbell, a professor at University of Georgia—is the latest to seek to define the behavior and traits of the millennial generation.

Views on this much-debated topic have varied widely among experts.

In 2000, the popular book Millennials Rising: The Next Great Generation, by Neil Howe and William Strauss, portrayed the group as engaged, high-achieving, and confident, among other “core traits.”

Ms. Twenge, the lead author of the new study, believes otherwise.

She has also published a book on the millennials, Generation Me: Why Today’s Young Americans Are More Confident, Assertive, Entitled—and More Miserable Than Ever Before, in which she writes: “I see no evidence that today’s young people feel much attachment to duty or to group cohesion. Young people have been consistently taught to put their own needs first and to focus on feeling good about themselves.”

That view is apparent in the new study’s findings, such as a steep decline in concern for the environment. The study found that three times more millennials than baby boomers said they made no personal effort at all to practice sustainability. Only 51 percent of millennials said they tried to save energy by cutting down on electricity, compared with 68 percent of baby boomers and 60 percent of Gen X’ers.

The study also found a decline in civic interest, such as political participation and trust in government, as well as in concern for others, including charity donations, and in the importance of having a job worthwhile to society.

The millennial generation has been raised in a culture that places “more focus on the self and less focus on the group, society, and community,” Ms. Twenge says

“The aphorisms have shifted to ‘believe in yourself’ and ‘you’re special,'” she says. “It emphasizes individualism, and this gets reflected in personality traits and attitudes.”

Even community service, the one aspect where millennials’ engagement rose, does not seem to stem from genuine altruism. The study attributes that gain to high schools in recent years requiring volunteer hours to graduate. The number of public high schools with organized community-service programs jumped from 9 percent in 1984 to 46 percent in 1999, according to the study.

Most of the study’s data point toward more individualism and less cohesion. The advantages of individualism are more tolerance, equality, and less prejudice, says Ms. Twenge. But the broader implication, she says, is not good.

“Having a population that is civically involved, is interested in helping others, and interested in the problems in the nation and the world, are generally good things,” she says. But Ms. Twenge does not believe this is happening. People are “more isolated and wrapped up in their own problems,” she says. “It doesn’t bode well for society in general.”