Worried college student looking at piggy bank © Alys Tomlinson, Cultura, Getty Images

Many U.S. high school students may be headed for trouble in college because they plan to major in a subject that doesn't match their interests.

Only one out of three students who took a recent ACT college assessment test intended to major in a subject that was a good fit for their strengths and preferences, according to the organization that administers the exam.

Nearly as many choose majors that are a poor fit, according to College Choice Report: Preferences and Prospects, a report by ACT, the Iowa City, Iowa, testing and research organization.

Picking the wrong major can be an expensive mistake. College students whose majors don't reflect their interests are less likely to graduate on time and more likely to drop out, said Steve Kappler, ACT assistant vice president and head of postsecondary strategy.

"If I change my major two or three times, it's going to take longer to get my degree," said Kappler, citing studies by ACT researchers. "A significant number don't complete, for a variety of reasons."

College consultant Lynn O'Shaughnessy said she frequently hears from families who are dead set on a college major that doesn't match the student's interests or abilities. One student, for example, planned to major in engineering even though he wasn't great at math. Another was told by her parents that her education would be paid for only if she majored in accounting. She did, O'Shaughnessy said, and she's employed -- but she's miserable.

"Parents and students are increasingly focused on pursuing majors that will provide a great salary," O'Shaughnessy said. "Their greatest fear is they will invest all this money and the kid will wind up working at Starbucks."

Career assessment tools, including the ACT Interest Inventory used in the study, aren't crystal balls. Many people discover interests in college, and future careers, that they never would have imagined in high school, college experts said.

Most students take the ACT in the spring of their junior year, although about 25 percent take the exam in their senior year.

Trying out different subjects should be a part of the college experience, said Northwestern University political science professor Andrew Roberts, author of "The Thinking Student's Guide to College."

"It always seems strange that a first semester freshman will take chemistry, history, English, and math when that is exactly what they took in high school," Roberts said. "Why not try linguistics or psychology or art history, to mention just a few subjects not offered in most high schools?"

Sidetracked by financial aid

Blindly pursuing a degree solely for financial reasons can backfire if a student washes out because of lack of ability or switches majors, or schools, because of a lack of interest, O'Shaughnessy said.

The misalignment of majors and interests is a big deal, said David Hawkins, director of public policy and research for the National Association for College Admission Counseling. "ACT has touched on something we've seen as a problem for a while."

Ideally, high school counselors would help students sort through their educational and occupational options. Three out of five students in the ACT study said they would welcome such help.

Many high schools don't offer that kind of assistance, however, so it may be up to parents to help uncover their children's strengths and figure out a career path, Hawkins said.

"Parents should check their own assumptions and prejudices at the door," Hawkins said. "It shouldn't be about what school bumper sticker you want on your car ... It should be helping the student understand and flesh out what they're passionate about, what lights their fire."

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Once parents are clear about their children's academic strengths and interests, they can help tidentifyhem identity potential majors and professions - which will in turn help them pick colleges that support those goals.

The good news, ACT's Kappler said, is that these conversations are much easier and more fun than parents' usual lectures about the importance of getting good grades.

"I've had this conversation with all three of my daughters," said Kappler, whose children are now in college. "It's a very easy conversation to have ... it's something teenagers want to talk about."