The child who insists on running up the slide at the playground is doing it for a good reason.

Chances are he's uninspired and trying to create more of a challenge for himself. And if the child is 9 or 10 years old, he is likely fully bored by the swings, slides and climbing gear.

Some child-development experts and parents say decades of dumbed-down playgrounds, fueled by fears of litigation, concerns about injury and worrywart helicopter parents, have led to cookie-cutter equipment that offers little thrill. The result, they say, is that children are less compelled to play outside, potentially stunting emotional and physical development and exacerbating a nationwide epidemic of childhood obesity.

Some psychologists suggest that not exposing children to risk can result in increases in anxiety and other phobias. Children who never climb trees, for example, are more likely to develop a fear of heights, according to a study in Norway. And encouraging free play, in an age of structured activities and computer games, is believed to be important in helping children develop physical and cognitive competencies, creativity and self-worth.

"We don't give our children enough roaming space to help them test their limits or to help them become confident in their physical skills," says Kathryn Hirsh-Pasek, a professor in the department of psychology at Philadelphia's Temple University. "Sometimes when we protect people too much they never learn to take healthy risks."