musingly breaking the fourth wall in the opening title credits, “Monkey Business” introduces Dr. Barnaby Fulton (Cary Grant), a thoroughly air-headed chemist who can’t seem to remember simple instructions (perhaps a precursor to “The Nutty Professor”). He’s either completely distracted or an extraordinary imbecile. “We’re going to a dance!” exclaims his outrageously patient wife Edwina (Ginger Rogers) when she tells him to turn on the porch light, lock the door, and meet her at the car – all steps he’s unable to accomplish without his mind wandering. His preoccupations are so severe that he’s basically unable to function – especially socially. “The genius at work again …”

Experimentations with monkeys (including 84-year-old chimpanzee Rudolph) at his laboratory have been fruitless of late; his work on a regenerative formula (the B-4 vitamin [or X-58], touted as a fountain-of-youth drug) has stagnated. But when he accidentally thinks about using heat in the process, a breakthrough is made at the Oxly Chemical Company, owned by magnate Oliver Oxly (Charles Coburn): a miraculous anti-aging serum (perhaps extreme cellular revival) is born – though it’s actually a simian experimenter that whips up the magic combination. “It’s the greatest thing in modern science!”

After Barnaby inadvertently ingests the formula, he instantly begins behaving as if 20 years old. He has an unlikely spring in his step and an uncommon swagger and adventurousness in his attitude. With Howard Hawks in the director’s chair, “Monkey Business” proceeds to embrace typical screwball antics, with Grant getting to act like a chipper lunatic. Of course, of immediate note is Oxly’s absentminded secretary Lois Laurel (Marilyn Monroe), who manages to show off her legs and don a bathing suit during her early sequences, with the camera making no qualms about soaking up her visual appeal. For this particular role, she’s quite perfectly cast. “By George, he’s taken it again!”

Hilariously, Rogers gets to join in on the flamboyance, too, going from sweet and serious to juvenile and energetic; this film offers a fun opportunity for these stars to act irrational and over-the-top. In Rogers’ case, she also gets to dance a little, leading to some of the goofier scenes. In its best minutes, “Monkey Business” musters some laugh-out-loud gags, though the periods between scientific experiments tend to drag a touch. Slapstick components and comical mixups full of rapid-fire conversations with overlapping dialogue help to spice up the proceedings, but the lulls when the formula wears off are apparent. “This proves there are no boundaries to science!”

With a swifter runtime, which would arrive at psychological transformations sooner, the film could have been better balanced and paced. Additionally, it’s not so much an age-reversing concept as it is an age-reducing one, which has the takers becoming infantile, resorting to childish hysterics and plenty of shouting, which are less enticing than something like a love potion or an inhibition-blocking one. Plus, the use of a monkey actor fails to add anything innovative; rarely does it do anything beyond jumping around and throwing objects (a stone-faced, monotonic kid is far funnier). Ultimately, while the production contains several memorable, significant jokes – ranging from the ambushing of an unsuspecting man by a horde of child savages to a rather mirthful switcheroo with a baby – the story just isn’t assembled cleverly enough to enable the whole to be as satisfying as the parts.

– Mike Massie