To most people, Jane Goodall, who has spent four decades studying chimpanzees in Tanzania, is the world's leading primatologist.

But Goodall, 65, also reveals her spiritual side with a book published in September, "Reason for Hope: A Spiritual Journey," and a PBS documentary airing Wednesday at 8 on WETA and Thursday at 11 on MPT.

The one-hour portrait from producer-director Emily Goldberg, who co-wrote the script, is narrated by Harrison Ford and features music by Bobby McFerrin and cellist Yo-Yo Ma. Phillip L. Berman, co-author of Goodall's book and a graduate of Harvard Divinity School, is the film's co-executive producer.

The documentary traces Goodall's life from her childhood in Bournemouth, England, to her current mission, traveling nearly 300 days a year to promote Roots & Shoots, an organization for students, and the Jane Goodall Institute for Wildlife Research, Education and Conservation.

Goodall also is seen walking around Gombe Stream Research Centre in Tanzania, her home and workplace, which she calls "my spiritual anchor."

Not surprisingly, the scientist says she believes in Darwinian evolution, but she also says she believes "in a spiritual force" in which "organisms are evolving a more and more complex brain and . . . can develop a new style of living that is dictated by culture rather than instinct."

The documentary recounts a period at Gombe when the chimps Goodall was observing suddenly turned warlike. Yet, as warlike as both man and chimp seem to be, she is still optimistic: "I have one absolute belief: that there is an all-powerful spirit that humans are moving towards, a destiny which is moving away from cruelty and destruction and towards love and compassion. This is our moral evolution, and we are just at the beginning. I just pray we don't destroy the planet before we reach it."

The elder of two daughters, Goodall grew up fascinated by sciences and a fan of Hugh Lofting's "Dr. Dolittle" stories and "Tarzan" (she calls the fictional Jane a "wretched woman . . . I would have made a much better mate for Tarzan").

But her family's finances were modest, and she didn't attend college, instead working as a secretary and waitress to pay for her passage to visit a friend in Kenya in 1957. It was a turning point: There she met anthropologist-paleontologist Louis Leakey, who, impressed by her serious interest, chose her to work on a pioneering study of chimpanzees.

A decade later, Goodall was named scientific director of Gombe. Her study of chimps occupied the next 30 years and documented similarities between chimps and humans, including the ability to make and use tools -- a skill previously thought to separate humans from other animals.

In 1964, a year before she finished her PhD at Cambridge University, Goodall married Baron Hugo van Lawick, a photographer sent by the National Geographic Society to document her Gombe chimp project. Their son, Hugh Jr. (called Grub), was born in 1967, but the marriage ended after 10 years.

In 1975 she married Derek Bryceson, director of Tanzania's national parks and a member of parliament. His death from cancer four years later shook her faith, but also was the catalyst for the spiritual renewal she discusses in her book.

Goodall's "The Chimpanzees of Gombe: Patterns of Behavior" was published in 1986, followed by five more books for adults and several for children. Named a Commander of the British Empire in 1995, she holds many awards and is the only non-Tanzanian to be awarded the Kilimanjaro Medal.

On Earth Day 1991, concerned about the rapid disappearance of the chimpanzees' habitat, Goodall founded Roots & Shoots to educate young people about the environment. Beginning with 16 secondary-school students who met on her veranda in Dar es Salaam, the organization now has more than 1,000 registered groups in 50 countries. Members ranging from kindergartners to college students are involved in projects caring for the environment, animals and their local communities.

"This kind of thinking and feeling of responsibility towards the environment or towards animals and people is something which, unless it's ingrained in children, is a very hard thing to do," she said. Roots & Shoots is "about making the world around you a better place."