Excerpt from The Human Age by Diane Ackerman, plus links to reviews, author biography & more

And like their human counterparts, orangs enjoy playing with iPads. But they're not addicted to them. They're just not as enthralled by technology as we are.

"Like, I have a seven-year-old son," Matt tells me. "He's on it all the time. Not Budi."

This kid likes the luminous screen, but he wouldn't sit for cramped hours just staring at it.

"How are we so enamored of this thing that's so unnatural and takes you away from everything?" Matt asks. "In one way, you'd like to have your own kids occupied at times, but when you see that the orangs are never going to get obsessed with it, knowing their huge intelligence, it gets me thinking: How smart are we to spend all this time staring at this thing? Like, even myself, you know, I don't test my memory anymore. I go . . . dee deedle dee dee." He demo-types on the screen. "I've become almost totally dependent on these machines. So am I weakening my brain?"

"Strawberry," a woman's voice says as Budi taps the strawberry on the screen. "Strawberry," she repeats when he finds a match. Matt rewards him with tidbits of fresh strawberries, apples, and pears. The lush tropical rainforests of Sumatra offer a cornucopia of hundreds of exotic fruits, the orangutan's favorite fare. Another app—of pooling water—fascinates Budi. It looks like water, ripples like water, and when he touches it, it plashes and burbles. But it doesn't feel wet. And when he lifts his fingers to his nose, he doesn't smell water. From his sensory perspective, it's strange. Not as strange, though, as interacting with humans and other orangutans via Skype.

The first time Budi saw Richard Zimmerman, the director of Orangutan Outreach, calling to him in a halo of light, he touched the screen, as if thinking, He's talking to me. Then, puzzled, he reached over and touched Matt's face. On the screen, a talking human, who knew him by name, was looking right at him and smiling, calling to him in a friendly voice. Why was Richard's face flat and Matt's face three-dimensional? He'd watched television lots of times, his favorite being nature films with orangutans. Matt sometimes showed him YouTube videos of adult male orangutans issuing their grown-up long calls, which always drew a fascinated stare. Yet the screen had never spoken to him. Hobnobbing with humans, rubbing shoulders with other orangs, meeting amiable strangers, playing with iPads, all had become staples of daily life. But this was an altogether different kind of socializing, and, although he didn't realize it, a step leading him deeper into the Human Age.

Parents today worry about the toll of screen time on their children's brains; the American Medical Association recommends none at all before the age of two. Yet a tech-enthused parent can even buy a child's "iPotty for iPad," a potty-training seat with built-in iPad holder, and find potty-training apps and interactive books at the iPad app store. Matt isn't concerned about Budi's iPad play, because unlike his own boys, Budi is a casual iPad user, and no one has studied the effect of screen time on the brains of orangutans. Would it make their senses and our own more alike? Anyway, because Budi is growing up surrounded by zoo life, human technology and culture will influence his brain in myriad ways, just as it does the brains of children. For good or bad, we use our rich imaginations to transfigure the world for ourselves and other creatures, banishing some critters we regard as "pests," while inviting others to share the curiosities we've invented (medicine, complex tools, food, special lingo, digital toys), urging them to blur the line with us between natural and unnatural. imagine, if you like, Budi holding an iPad whose apps and games are chapters in this book. By touching the screen, he opens one, then another, merely listening to the story as human voices stream past, or watching colorful faces and vistas intently. In some he even catches a glimpse of himself, iPad in hand, as either an ape kid at play or a vital ambassador for his dwindling species. Both roles are his real-life destiny. Lifting one hairy orange finger over the screen, Budi hesitates a moment, then touches the first chapter. When he does, a snowstorm opens up, with college students dashing between buildings, books clutched inside their parkas . . .

Excerpted from The Human Age: The World Shaped By Us by Diane Ackerman. Copyright © 2014 by Diane Ackerman. With permission of the publisher, W. W. Norton & Company, Inc. All rights reserved