Twins (1988), a comedy where the goofily paired Arnold Schwarzenegger and Danny DeVito play the eponymous siblings, is a lot less silly than you might expect it to be; it can even be surprisingly sweet. What this mostly-just-amusing movie lacks in laughs is made up for in Schwarzenegger and DeVito’s chemistry, which really does come to feel brotherly the better their characters get to know each other. 

The pair starts Twins not knowing about the other. They’re the result of a 1950s scientific experiment where the sperm of six men were implanted into a young woman (Heather Graham) in the hopes of creating a perfect specimen. Greek statue-like Julius (Schwarzenegger) was the desired outcome. Unplanned Vincent (DeVito) is, as a character mid-movie indelicately puts it, a collection of all the leftover “crap.” Both boys were told in childhood that their mother died after giving birth; they spend their upbringings separately. Julius has been raised by one of the experiment’s guiding scientists, Werner (Tony Jay), on a South Pacific Island, where he’s learned to speak 12 languages and has gobbled so many books on every subject that he’s practically a genius. Vincent spent a few years in an orphanage before prematurely ditching it to forge his own path. It hasn’t led to anything great. He’s a minor grifter indebted a scary amount to various loan sharks and to the city, to whom he owes a sky-high amount in parking tickets.

Julius decides to travel to Los Angeles to find Vincent when he finally learns of his existence on his 35th birthday. He bails him out of jail, which is where they first meet, and though Vincent at first tries to keep running away from the imposingly brawny man he struggles to buy is his long-lost twin, they eventually start to bond, Julius giving some insights into conflict de-escalation and Vincent sharing the best way to elevate a microwavable eggplant parmesan. DeVito is scabrously funny throughout Twins, but Schwarzenneger is the movie’s true comic gift. Hulking around in a man-child outfit — a too-big blazer, baggy knee-length shorts, and black high-tops — he leans into his character’s disarming innocence and general deference without resorting to a caricatured portrayal of sheltered arrested development.

Twins is able to coast a decent amount just on how good DeVito and Schwarzenegger are together. When it tries to pad things out — there emerges an action movie-esque subplot where Vincent stumbles upon a technology that’s worth a lot and decides it’s necessary to travel cross-country to sell it, and the duo is given love interests in the proportionally charming Kelly Preston and Chloe Webb — there’s a crowded, too-many-cooks feeling that makes it not that big a shock that there are four credited screenwriters: William Davies, Timothy Harris, William Osborne, and Herschel Weingrod. But it never gets so busy that you lose interest. Producer and director Ivan Reitman maintains such warm pleasantness that if one is to have any ill will toward Twins, it might have more to do with it not mining the absurdity of its premise for more jokes.