In many cultures around the world, play is considered an important part of childhood — but only of childhood. Adults don’t play — at least not in the same way that children do. Parents may experience vicariously the pleasures of play when they see their kids having fun. But they don’t fully partake in their kids’ unmitigated joy. That is the exclusive domain of childhood, irretrievably closed off to grown-ups.

Play for the sake of playing loses its legitimacy quickly as we grow older. We find it harder to give ourselves permission to spend time doing something that serves no particular purpose. Over the course of our lives, we may attempt to regain a sense of being at play — at least once in awhile. We call it a vacation or getaway.

But recreational activities, even favorite sports or hobbies, are not the same as playing. When we play as adults, we typically play competitive games or push ourselves to test our limits. Competing and winning become the focal point of our play — sometimes to the point at which playing feels more like work than fun. “Working hard and playing hard” may be a good formula for a balanced lifestyle, but it will never get us back to the utter bliss of being completely immersed in play as we were when we were little.

It is indeed amazing that we should lose the ability to play despite the fact that most of us cherish our childhood memories and especially with regard to our playful activities. Parents often feel conflicted whether they should let their kids have more fun at play or push them to ever greater achievements at school and at sports. A healthy balance seems hard to find.

One reason for this confusion may lie in the fact that we know so little about the nature of play. Having a good time playing, of course, can make us feel good. But is it beneficial in any other way or is it merely a waste of time that could be used in more productive ways?

It is comforting to think that playing has many benefits, though they cannot be measured as clearly as academic or athletic achievements. They are very real, nevertheless. Play can teach many skills that structured learning cannot; most importantly, perhaps, the skills of building functional human relationships. Play helps prepare kids for life, so goes the argument in comparison to young animals who build up their survival skills by playing with their siblings. There may be some truth to that, but scientists who study “play behavior” are not so sure that that’s the whole story; not with regard to humans, anyway.

In recent years, we have learned a great deal more about the growth and development of the brain in children. Not surprisingly, play seems to have a significant role beyond the acquisition of knowledge and skills. Some clinical studies suggest that playing has direct neurological effects on children and that being deprived of sufficient play time can have negative consequences over time, comparable to extended lack of sleep. There is no clear consensus about whether or not play has a positive stimulating or a positive calming effect on the brain, or perhaps both. But this much seems obvious: Play is an important component for the healthy development of the human brain.

If this is true, then this also has implications for our mental health at any age. Contrary to what they thought in the past, neurologists no longer believe that we only lose brain cells throughout our lifetime, but that we also generate new ones, even at an advanced age. In other words, our brain keeps developing long after the completion of our physical growth. We all know that a sufficient amount of stimulation as well as relaxation are central to our physical and mental well-being. That never changes. We call some people who are no longer young in years “young at heart,” by which we mean that, despite their age, they have not lost their agility, creativity, zest for life or playfulness.

So here is my advice: Don’t deny your children or grandchildren their play, and don’t deny it for yourself. Keep on playing as long as you can. It’s good for your health — in every way.

Timi Gustafson is the author of “The Healthy Diner – How to Eat Right and Still Have Fun.” Her book is available in bookstores and online at www.thehealthydiner.com or at Amazon.com. To receive her free monthly newsletter by e-mail, send a request to tmg@timigustafson.com.