IN "INSTINCT," psychiatrist Theo Caulder (Cuba Gooding Jr.) practically flips in the air when he hears about Ethan Powell (Anthony Hopkins), a primatologist currently manacled and medicated at a prison for the criminally insane.

Powell, who spent much of his adult career studying gorillas in the Rwandan mountains, has turned a little too animalistic for his own good.

After a tragic incident in Africa, he's charged with several murders. He has stopped speaking. He's prone to sudden violence. When he's escorted back to the United States and catches a glimpse of his daughter (Maura Tierney) at the airport, he goes berserk.

Caulder smells something more alluring than an interesting case. He smells a bestseller.

"I'm ready for this, Ben," he tells his mentor, Dr. Ben Hillard (Donald Sutherland).

Receiving Hillard's blessing, Caulder heads to the rundown Harmony Bay Correctional Facility, tape recorder in hand, ready to take on the big, silent, shaggy one.

Let's see: He's going up against a character played by Hopkins, a brilliant yet ruthless individual capable of mind games with anyone who dares to question him. Hopkins can root out your deepest, darkest secrets. He also loves fava beans, a nice chianti and . . . . Well, no, he doesn't. But you could be forgiven for thinking -- occasionally -- that you just stumbled into "The Silence of the Apes."

Will Caulder ever get Powell to talk? And if so, what hope is there of pulling him back into the ranks of humankind? It doesn't look as though the psychiatrist will get help from the one-dimensionally evil prison warden (John Aylward) or Dr. John Murray (George Dzundza), a staff doctor who has become defeated by this inhumane institution where guards use intimidation games to control the prisoners.

Eventually, Caulder has to reach out to Powell's daughter, who may help explain why, in 21 trips to Africa over 12 years, he never took his family with him.

"Instinct," produced by the team that made "Phenomenon" -- including director Jon Turteltaub and screenwriter Gerald DiPego -- has some thought-provoking moments. But they're couched in the formulaic strictures of a Walt Disney adult picture. You always know you're being subtly instructed.

In Africa, for instance, Powell learns to avert his eyes so as not to challenge gorillas. Cut to Harmony Bay, where prison guards routinely challenge cowering inmates for staring at them. And if Caulder really wants to understand Powell, he's going to have to realize humans are basically opposable- thumbed alpha males who exploit the world in the name of power, civilization and success.

The movie's most compelling element is the Cuba-Tony show. This is about Caulder's desperate desire to reach Powell at any cost, and his patient's equally determined resistance. Both are perfectly up to the task. Hopkins's skills need little reiteration. This is another effortless display of endearing intimidation. It's a pleasure to watch Gooding, as well. Athletic, quick on his feet and agonizingly intense, he pushes as far into this jungle of cliches as acting allows. But beyond that point, the movie's impenetrable without a machete.

INSTINCT (R, 126 minutes) -- Contains profanity and violence. Area theaters.

CAPTION: Cuba Gooding Jr. and Anthony Hopkins spar in the film "Instinct."