If you become fixated on Peter Sarsgaard’s obviously fake beard in “Experimenter,” that’s all right.

This is a movie that wants you to notice the artifice: it occasionally includes patently false backdrops, an otherwise unexplained elephant, and a protagonist speaking nonchalantly about his own death as he addresses the camera. Writer-director Michael Almereyda has been nothing if not an experimenter himself — his work includes the Gen-X “Hamlet” (2000) and a vampire film partly shot with a toy video camera, “Nadja” (1994).

His approach works beautifully in “Experimenter,” an unexpectedly haunting account of the man who concocted a famous 20th-century psychology study.

If you don’t know the name Stanley Milgram, you know the obedience experiment: At Yale in 1961, Professor Milgram found that two-thirds of his subjects continued administering electric shocks to another participant until they reached the maximum level (the shocks were fake, but the subjects could hear the other person pretending to yelp in pain in the adjacent room).

Milgram’s experiment made his name — and was quickly seized on as an explanation of how the Holocaust could have happened — but was also criticized for its ethically queasy design. Later in life Milgram came up with the six-degrees-of-separation theory, usually credited to Professor Kevin Bacon.

The movie’s Milgram is sincere and self-satisfied — a good role for Peter Sarsgaard, who brings just the right touch of smugness to the part. Winona Ryder plays Sarsgaard’s loyal but subtly uneasy wife, and Jim Gaffigan plays a colleague.

Almereyda deploys his distancing devices liberally, and likes the idea of a movie commenting on itself; at one point Milgram visits the set of a 1970s TV-movie starring William Shatner and Ossie Davis (played by Kellan Lutz and Dennis Haysbert) — a set-up that might make an easy target, but it turns into something more interesting.

Why tell the story this way? Almereyda might be fretting about how blind belief in the movies could be as dangerous as blind obedience to authority — so he never lets us forget that an experiment is going on.

That’s fair. What’s interesting is that “Experimenter” becomes a compelling experience, a film of ideas that is almost a tone poem, too (thanks in part to Bryan Senti’s music).

The seriousness and self-reflection of the mid-20th-century come to life in a really engaging way, all the more so for also including William Shatner and beatnik beards.

“Experimenter” (3½ stars)

This story of psychologist Stanley Milgram (Peter Sarsgaard) and his famous 1961 experiment on obedience is full of distancing devices, yet it becomes a compelling portrait nonetheless. Director Michael Almereyda gets a fascinating lesson going in the costs of blind obedience.

Rating: PG-13, for subject matter

Showing: Seven Gables theater