When Harriet Smith fell in love with triplet monkey babies 34 years ago, little did she know they would shape her ideas about parenting her own kids and give her an unusual perspective in counseling patients and result in a book deal. The psychologist's first book, "Parenting for Primates" (Harvard, $29.95), chronicles her experiences as the "Monkey La-dy," who has raised more than 50 cotton-top tamarins.

Smith wrote the book to help parents realize that they don't automatically know how to raise children, and that their instincts sometimes need to be developed.

Smith's story dates back to her graduate work in primatology at the University of Arizona. As part of a research project, she volunteered to keep the tiny triplets in a cage by her bed and set an alarm for every two hours so she could bottle-feed them.

Soon, however, the monkeys' usefulness as research subjects ended, and Smith adopted them, along with three others from the school's lab.

The fun started when one pair became parents, Smith says.

"I was awakened to this screaming," she recalls. "I ran into the living room, and there were two tiny babies clinging to the mom's back, and she was frantically trying to flick (them) off of herself."

Smith was able to calm the adults and clean up and feed the infants, but in the days to come, it became clear the parents not only had no interest in caring for their young, they were hostile toward the babies, sticking out their tongues and making threatening gestures. However, Rachel, a tamarin who'd been captured in Colombia as an adult and had been raised in a normal family group, became interested in the babies and took over as foster mother. For years, Rachel continued adopting babies birthed by Smith's other tamarins. Through Rachel's care, those monkeys grew up to become good parents, and even the original tamarin parents eventually learned parenting skills.

While all this monkey business was happening, Smith had two children of her own and noticed in her psychology practice that parents would beat themselves up over not knowing how to raise their kids.

"Parenting isn't automatic for people any more than it is for monkeys," she says. "Mothers say to me, 'I don't have that maternal instinct — what do I do?' A lot of couples I've worked with feel so inadequate."

In her book, Smith describes normal and abnormal parenting behavior in humans and nonhuman primates. Chapters deal with the roles of mothers and fathers, weaning, baby sitters, independence, single parenting and the empty nest.

Smith expects criticism from those who think she has blurred the lines between monkeys and people. "I'm not advocating that we become chimpanzees," she says. "I'm just saying, 'Let's see what are some things that have stood the test of time that our kids could benefit from.' "