WASHINGTON—With unemployment at its highest level in decades, the U.S. Department of Labor issued a report Tuesday suggesting the crisis is primarily the result of millions of Americans just completely blowing their job interviews.

According to the findings, seven out of 10 Americans could have landed their dream job last month if they had known where they see themselves in five years, and the number of unemployed could be reduced from 14.6 million to 5 million if everyone simply greeted potential employers with firmer handshakes, maintained eye contact, and stopped fiddling with their hair and face so much.

"This economy will not recover until job candidates learn how to put their best foot forward," said Labor Secretary Hilda Solis, warning that even a small increase in stuttering among applicants who are asked to describe their weaknesses could cause the entire labor market to collapse. "If we're going to dig ourselves out of this mess, Americans need to stop wearing blue jeans to interviews, even if they're nice blue jeans, and even if that particular office happens to have a relaxed dress code."

"They also need to start bringing extra copies of their resumés, as it will show they are prepared and serious," Solis added. "And, by the way, how hard is it to send a hand-written thank-you note afterward? Anyone can dash off an e-mail."

A federal survey of employers found that nearly half of job-seeking Americans botched their interviews by responding no when asked, "So, do you have any questions for me?" Among candidates strongly qualified to perform the jobs they were applying for, 36 percent didn't bring a notepad or pen to the interview, and 16 percent were thrown off guard when the interviewer broached topics unrelated to work, such as the weather, sports, or personal hobbies.

Twelve percent, employers said, did this kind of nervous throat-clearing thing.

"If applicants would just say yes when asked if they played softball or liked golf, we could add 350,000 jobs to the private sector," Deputy Labor Secretary Seth Harris said. "The fact is, right now, today, approximately a third of the country's manufacturing positions are vacant. Auto plants across the country, especially in Detroit, are sitting there just waiting for people to come in and build cars."

"You may be a qualified candidate, but none of that matters if you walk into that interview lacking confidence," he added. "Don't act too confident, though. And don't joke around too much. And don't be overly friendly or ask too many questions. But be yourself."

The Labor Department confirmed their statistics don't take into account the estimated 20 million citizens who were unable to get interiews in the first place because of formatting errors in their resumés, or cover letters that slightly exceeded one page.

"At this point, hiring someone who doesn't use bulleted lists, strong action verbs, or boldfaced keywords is completely out of the question," said public relations executive Max Werner, who has been looking for office managers and a CFO since 2008. "And if you're going to end your cover letter with 'best wishes' instead of 'sincerely,' I don't care how experienced you are—you won't be working for me."

President Obama, who last week signed a law extending unemployment benefits, said the legislation would also address joblessness by creating a $1.2 billion program aimed at training Americans to use firm but approachable body language to make a great first impression.

"My administration remains fully committed to putting citizens back to work by making sure they show up at least 15 minutes early to their interview and never badmouth a previous boss," said Obama, flanked by unemployed Americans during an address from the White House Rose Garden. "Our new 'Nail the Interview, Score the Job' initiative will help regular Americans like Paul and Tracy here remember that they should prep ahead of time by learning a few things about the company they want to work for."

"And that little things," he continued, "like making sure your socks match, matter."