Have fun with biology in ‘Totally Human’

The other day, you were outside playing and you hit your head.

Ouch! It hurt so much that you started to cry, both eyes watering. Your ears rang and you cried so hard, you started to hiccup. But you were fine, you felt better later and you even managed a laugh when your dad tickled you a little.

Did you ever wonder why you cry when you're hurt, hiccup sometimes or laugh? Why can't you tickle yourself? Find out those questions and more in the new book "Totally Human" by Cynthia Pratt Nicolson, illustrated by Dianne Eastman.

There is nobody else like you in the whole universe. But in some ways, you're just like everybody else on the planet.

You inherited genes from both your parents, who got genes from their parents, who got well, you get the picture. We're all related, which means you and every human on the planet have a little bit of genetic material in common. And by the way, chimpanzees share 98 percent of our genes, too!

And if you think that's odd but cool, then consider this: hiccups, farts, burps, throwing up, crying, yawning, playing, getting tickled and laughing are all pretty weird, too. But your totally human body needs them all.

Scientists think that hiccupping may be something you share with baby frogs and their developing lungs. The food you eat is digested by bacteria that live in your body (eeuww), which makes gases, and those have to come out somehow (double eeuww). Tossing your cookies is an evolutionary way for your brain to rid your stomach of cookies or other foods it thinks are toxic.

Crying and yawning are both ways of making our totally human bonds stronger, say scientists. Playing is the same, and it's a way for youngsters -- both totally human and animal -- to learn skills they'll need later in life.

Tickling, scientists believe, has to do with the element of surprise and danger, which is why you can't tickle yourself (and why it's hard for a kid to tickle an adult). And if you laugh when you're tickled, that's another thing you share with animals. One scientist was surprised when he recorded the quiet sounds of rats being tickled. He heard tiny little giggles! Gitchee, gitchee.

Have a kid who's full of why? Then grab this fun, wonderfully illustrated book that will teach the Whys One a thing or two.

"Totally Human" takes a good look at the icky, interesting things our bodies do, the quirks we possess (and share with other mammals), the fascinating reasons scientists think we are the way we are and boils it all down in short, just-right, kid-friendly language. Nicolson's mini-chapters are lively, and they'll make kids laugh as they learn. The collage-like illustrations by Eastman will keep them turning the pages.

Though this book is meant for a 7- to 12-year-old, you might be tickled at what you learn here, too. For you and your child, "Totally Human" is totally cool.

Terri Schlichenmeyer's children's book reviews appear weekly in View.