In this time of global anxiety, it might be reassuring to know there is a group of people on Earth who do not worry. In fact, this group -- which lives deep in the shrinking Amazon rain forest -- does not even have a word that conveys worry. The happy-go-lucky Pirahã also do not accumulate possessions, do not create art, are sexually open and are immune to 300 years of lectures by hectoring Christians who promise an even better life.

But before you get too envious, this small community has customs that would rattle our Western sensibilities. They will let a woman die miserably from a breech birth, and they occasionally kill orphaned babies. Simple quality-of-life chores such as clearing brush and garbage from around their open-air huts to control vermin appear to escape them.

These are just a few of the observations that author, linguist and fallen Christian missionary Daniel Everett reveals in his intriguing if inconsistent book, "Don't Sleep, There Are Snakes." Everett, the chair of Languages, Literatures and Cultures at Illinois State University -- with his wife, Keren, and three children in tow -- spent 30 years with the Pirahã, studying their one-of-a-kind language.

While the second half of the book reads like a dense university lecture parsing Everett's controversial dissection of the unique Pirahã language, the first half is punctuated by more readable, narrative snapshots. The most compelling of these stories occurs in 1977, at the beginning of Everett's stay, when he rushes his deathly ill malarial wife and daughter from the isolated village to medical care.

The harrowing experience showed Everett that the Pirahã do not express empathy in the way we might. Death is a constant and, unlike us, the Pirahã have no expectation of long lives. They do not feel "obligated to suspend normal daily activities just because someone is sick or dying," Everett writes. "This is not callousness. This is practicality."

White guys mucking around in the jungle with journals and tape recorders is an old and mostly exploitative story. Western romanticism often surfaces and, despite the best of intentions, Everett displays a bit of this too. By the end, Everett, who has renounced his religion and lost his family as a result, is gushing with the same fervor he once used to try to win the natives over to Jesus. The Pirahã, he announces, are "happier, fitter, and better adjusted to their environment than any other Christian or other religious person I have ever known."

Stephen J. Lyons is the author of "Landscape of the Heart" and "A View From the Inland Northwest." He lives in Monticello, Ill.