For years, soft-headed types have looked at highly productive work groups and noticed something. Workers in the top performing groups also had higher morale than workers in other groups.

"Aha!" thought the soft-heads, "happiness causes productivity." Never mind that there's no good research to support that. Never mind that the fields of business are littered with the dead bones of companies that believed it.

Take the example of a small, regional air carrier from some time ago. Company management believed that if they made their workers happy, productivity and profitability would follow. They set about doing the things they thought would make their people happy.

They paid their people very well, much more than other airlines. They gave them lots of perks on the job. And they gave employees lots and lots and lots of paid time off.

Workers got paid time off for just about every holiday on anyone's calendar. They got paid time off for their birthday, unless they worked. Then they got triple time. There was lots of paid family leave. You get the idea.

Productivity didn't go up. The airline was no more productive than the competition. But it was a lot less profitable because it was paying a whole lot more than competitors for the same amount of work. Eventually the airline went out of business. Then the employees were very sad.

"Ok," you're thinking, "If top performing groups are filled with workers who are both happy and productive, and if happiness doesn't cause productivity, it must be the other way around." Nope. It turns out that some slave ships make pretty good time.

Consider the early years of the Ford Motor Company. Henry Ford's vaunted assembly line set the pace of work and it was a brisk pace indeed. Workers and their families were scrutinized by Ford security and those of "poor moral character" were let go.

The Ford assembly line wasn't a happy place to work then. But it was very productive. It was so productive, in fact, that Ford was able to buy vast holdings all over the world without borrowing a penny. The profits from the Model T were enough.

If you're starting to despair, don't. Stay with me. Because we know what it takes to grow work groups that are both productive and happy.

To be productive and happy, people need to feel like they're being treated fairly. They want to make enough money. They want their salary and benefit package to be comparable to other people doing similar work within the company and in other companies.

After that, though, monetary rewards don't make a lot of difference. If people are being treated fairly and paid enough by the company, it's their boss that makes the big difference.

Jeff Immelt is now the CEO of General Electric (GE). But his dad worked on the line for GE while Jeff was growing up. Here's what Jeff Immelt says.

"When I would sit around the kitchen table with my dad, I never knew who the CEO of GE was. I knew my dad's boss.. .. [when he had a bad boss] He came home in a bad mood, uncertain about the future. And when he had a good boss, he was pumped."

That's the secret to a happy and productive workforce. Give them good bosses up and down the line.

Don't concentrate on making your workers happy or on making them productive. Instead concentrate on making your bosses good.

Select your bosses, the people responsible for group performance, from a pool of qualified and engaged workers. Give them the training they need to be a good boss. Give them regular and usable feedback on how they're doing their job.

Then, help your new bosses become good, experienced bosses. Keep training in basic one-on-one leadership skills, but go beyond the training room. Help your bosses get development opportunities where they can develop both skills and vision. Help them connect with other bosses to discuss leadership situations and issues.

It's no mystery, but it's not easy. It takes time and resources. But building a cadre of great bosses is the way you build workgroups with high morale and high productivity. And those workgroups help you build a profitable company for the ages.