Scientists at the Yerkes Regional Primate Research Center in Atlanta, Ga., are sewing the eyelids of infant primates shut to see how that affects their behavior. At the New England Regional Primate Research Center, a database is maintained of self-inflicted wounds -- fingers bitten off, holes chewed in arms -- among populations of normally social monkeys kept in solitary confinement.

Welcome to the world of primate behavioral science!

We hopped aboard an Air Lanka jet to see if there might be a viable alternative way to investigate simian behavior. A way of learning about our closest biological relatives without having to resort to the kind of experiments that -- when applied to human subjects -- incurred some stiff penalties at the end of World War II.