Question: What's the difference between dinosaurs and family vacations? Answer: Dinosaurs are already extinct.

If there's one thing Americans need more of, it's vacation time. Sure, we've got the Grossest Domestic Product on the planet. But American society is no longer healthy for children and other living things. Consider that in 1980, people in only 10 other countries lived longer than we do. Now, people in 41 other countries live longer. Consider that if you lived in Europe you'd be only a little more than half as likely to suffer from chronic illnesses such as heart disease, hypertension and Type 2 diabetes after age 50.

And why is that? A big reason is time. Europeans work about 300 fewer hours on average each year than Americans. Consequently, they have a lot more free time to exercise, eat slowly and healthily, sleep longer and socialize with friends and family. Each of these does wonders for their health.

This explains a big part of the fact that they only pay a little over half as much as we do for health care.

A big part of the extra free time Europeans enjoy can be attributed to their longer vacations. At a minimum, every European worker is guaranteed four weeks paid vacation by law; most get six or more.

By contrast, a new poll of 1,000 Americans, conducted by the Opinion Research Corporation found that 29 percent of American workers took no paid vacation time last year and another 24 percent took a week off or less.

Have you noticed the number of Europeans on the streets of San Francisco this summer? Or on the trails in Yosemite? It's not only because they have the time to travel. They have the money, too. Their generous paid vacations haven't meant economic ruin. The euro has been soaring relative to the dollar, and U.S. firms have been investing heavily, and profitably, in Europe, earning - contrary to popular knowledge - far more from Germany than from China.

This is not about slacking or laziness. Meaningful labor is an essential element in the pursuit of happiness. But so is free time to enjoy the fruits of that labor. It's about balance, really, and in our zeal to out-produce and out-consume everyone else, America has gotten out of balance.

A recent Pew Research Center survey found that more middle-class Americans (68 percent) responded that having free time was a high priority for themselves and their families than any other goal. By contrast, only 12 percent said becoming wealthy was highly important to them.

If we really want more time, here's a simple place to start: Let's guarantee three weeks of paid vacation to all American workers (prorated for part-timers), a proposal of my nonprofit organization, Take Back Your Time (see www.right2vacation.org). One hundred thirty-seven countries in the world have paid vacation laws; the United States is the only industrial country that doesn't.

The new Opinion Research Corp. poll found that 69 percent of Americans would support a law guaranteeing paid vacation time to all workers, with a plurality favoring a time period of three weeks or more.

Other studies show that men who take regular vacations are 32 percent less likely to die of heart attacks than those who don't. The Framingham Heart Study found that women who don't take vacations are up to eight times more likely to suffer from heart disease than women who take two vacation breaks a year.

We're talking big numbers here - and high costs to our health care system. Another study showed that women who don't take vacations are more than twice as likely to suffer from depression as those who do. It isn't rocket science; vacations make us healthier.

They also make us more productive. An Air New Zealand study found that after vacations, workers got an extra hour of quality sleep and their reaction times were 30-40 percent faster. And the gains lasted for months. This doesn't happen with "daycations" - a day off here and there, usually spent running errands. We need time to unwind. Getting it can reduce workplace stress and burnout dramatically.

Here's a scary statistic: The number of Americans taking family vacations has dropped by a third in the past generation. Yet experts like University of Minnesota family therapy Professor William Doherty say such vacations are a primary source of bonding, and among the family experiences most likely to be remembered by children. With less vacation time, children are also more likely to experience "nature-deficit disorder." Fewer get out in the woods with their families or spend a night there.

Vacations matter for health, family, the environment and productivity. Enlightened businesses recognize that. Many, like Patagonia, offer their employees generous vacation time. But the majority does not. An enlightened United States would protect the right of workers to a block of vacation time each year.

Are you taking a vacation this year? If not, you just might end up with Irritable Growl Syndrome. Ever notice that people seem crankier these days? Been caught in traffic jams when road rage erupts? Slammed down the phone in disgust when an automated answering service cheerfully told you your call would be answered "in approximately 57 minutes" and that if you hung up you'd lose your place in line? Been asked to work overtime one too many times? Snarled at your boss when he or she told you it was too bad you'd prepaid for those airplane tickets but the office couldn't get along without you for a week this summer? Well, you get the idea.

As another summer comes to a close and fewer of us get the real pause that refreshes, it's time to vaccinate America against the scourge of Irritable Growl Syndrome. It's time to guarantee paid vacations for all Americans and restore balance to our hurried lives.