I was recently listening to one of my favorite podcasts—Hidden Brain, with Shankar Vidanthum. As usually happens when I listen to this podcast, it snatched an idea that had been quietly resting undeveloped in the back of my memory file, pushed it into my conscious brain and then injected clarity. The question posed on this October 1, 2018 podcast, Man Up, was why, when there are millions of jobs that need to be filled in the US, are there also millions of men—approximately seven million–who have left the workforce, have permanently stopped looking for employment.

These are primarily men ages 25-54, so certainly individuals you would expect to be working in this economy. To put this into perspective: In 1954, the rate of participation by this group in the labor market was 98%. In 2017 it had dropped to around 88 percent. In 1940, 14.6% of men in this category were unemployed, primarily because the US was coming out of a ten-year depression when many job searches proved futile. But in 2015, the work rate for this group was slightly lower than in 1940.

The unemployment rate, at 3.9%, doesn’t include people who have essentially given up on re-entering the workforce. And when you include these individuals, the unemployment rate doubles. So what is going on? If employers are desperate for workers, and these people need work, why are they not moving into these job markets?

A significant contributing factor, it appears, is that many of the jobs available—nursing, physical therapy, other healthcare jobs—have traditionally been held by women, and men don’t want ‘women’s work.’ I can see you rolling your eyes and thinking, ‘Oh c’mon, get over yourself, it’s a job.’ But the simple answer and the impatient response do not take seriously the core issues at the heart of this conundrum for men. Disclaimer: I do not usually spend much time trying to figure out the reasons men do things, but this just grabbed my attention.

It isn’t just that these jobs are usually inhabited by females; it is that taking such a job presents an existential challenge for men, and causes them to question whether they can be ‘real men’ if they work in historically female professions. And to add a bit of irony, men are the ones who created the definition of ‘real man’ and continue to draw the boundaries around what is acceptable male behavior. They have, in essence, painted themselves into a corner. Their definition of manliness is so narrow as to offer few options when confronted with a choice between supporting themselves and their families—a cornerstone of approved male behavior—and retaining a self-image that rejects behaviors that have come to be called ‘pussified.’

Women today have access to a far greater range of acceptable behaviors than males, because what is considered feminine now encompasses whatever a woman needs to accomplish in order to fulfill her role as mother and community member. If she is a single parent, or a mother in a two-parent household, who manages to secure training in carpentry in order to provide a better future for her family, this is acceptable, perhaps even applauded. At the same time, she retains her roles as nurturer and community builder. One does not foreclose the other; in today’s society they are viewed as complementary. Necessity dictates it.

It’s not as easy for men, because their male friends do not make it easy. Think about the response from a group of guys who learn that one of them is in training to become a nurse. We all know the response. It is predictable, because men have made it difficult for other men to expand the definition of ‘real man.’ Turns out men are more afraid than women to color outside the lines.