At a recent dinner in Washington, D.C., with representatives from major American manufacturing companies, I listened as the talk turned to how hard it is to find qualified applicants for jobs.

"What exactly are the skills you can't find?" I asked, imagining that openings for high-tech positions went begging because, as we hear so often, the training of the U.S. workforce doesn't match up well with current corporate needs.

One of the representatives looked sheepishly around the room and responded: "To be perfectly honest . . . we have a hard time finding people who can pass the drug test." Several other reps gave a knowing nod. Applicants were often so underqualified, they said, that simply finding someone who could properly answer the telephone was sometimes a challenge.

More than 600,000 jobs in manufacturing went unfilled in 2011 due to a skills shortage, according to a survey conducted by the consultancy Deloitte.

The problem seems soluble: Equip workers with the skills they need to match them with employers who are hiring. That explains the emphasis that policy makers of both parties place on science, technology, engineering and math degrees—it is such a mantra that they're known by shorthand as STEM degrees.

"But considerable evidence suggests that many employers would be happy just to find job applicants who have the sort of "soft" skills that used to be almost taken for granted." -Nick SchulzAmerican manufacturing has become more advanced, we're told, and requires computer aptitude, intricate problem solving, and greater dexterity with complex tasks. Surely if Americans were getting STEM education, they would have the skills they need to get jobs in our modern, high-tech economy.

But considerable evidence suggests that many employers would be happy just to find job applicants who have the sort of "soft" skills that used to be almost taken for granted. In the Manpower Group's 2012 Talent Shortage Survey, nearly 20% of employers cited a lack of soft skills as a key reason they couldn't hire needed employees. "Interpersonal skills and enthusiasm/motivation" were among the most commonly identified soft skills that employers found lacking.

Employers also mention a lack of elementary command of the English language. A survey in April of human-resources professionals conducted by the Society for Human Resource Management and the AARP compared the skills gap between older workers who were nearing retirement and younger workers coming into the labor pool. More than half of the organizations surveyed reported that simple grammar and spelling were the top "basic" skills among older workers that are not readily present among younger workers.

The SHRM/AARP survey also found that "professionalism" or "work ethic" is the top "applied" skill that younger workers lack. This finding is bolstered by the Empire Manufacturing Survey for April, published by the Federal Reserve Bank of New York. It said that manufacturers were finding it harder to find punctual, reliable workers today than in 2007, "an interesting result given that New York State's unemployment rate was more than 4 percentage points lower in early 2007 than in early 2012."

The skills shortage is not just an absence of workers who can write computer code, operate complex graphics software or manipulate cultures in a biotech lab—as real as that scarcity is. Many people lack what the writer R.R. Reno has called "forms of social discipline" that are indispensable components of a person's human capital and that are needed for economic success.

This is not an exercise in blaming the victim. There's plenty of fault to go around, from America's inadequate K-12 education system to the collapse of intact families and the resultant erosion of human and social capital in many communities. But we shouldn't delude ourselves about the nature of the problem facing many of the millions of Americans who can't find work.

Mr. Schulz is DeWitt Wallace Fellow at the American Enterprise Institute and editor of American.com.