In Blade Runner, Deckard says that it takes 20-30 questions to identify a replicant (and a hundred for Rachel).

However, when I saw the movie yesterday, I realised that even after the first question or two it becomes blindingly obvious that the respondents think and act like machines ("I'd kill it!").

The only explanation I can come up with why it then would take dozens of questions, would be that the human population has gone cynical from the apocalypse and all come off as non-empathic.

I can't remember the detail at which the novel describes the Voight-Kampff test, but the logical flaw could possibly have been introduced during the screenwriting process.

Any other explanations or comments?

  • 5
    Really? You'd blow someone away after two questions just because they weren't empathetic enough for you? The point is to be sure. It's about asking the same question in muliple forms that enables one to tell the difference between a less empathetic human and a replicant faking it,
    – Paulie_D
    Commented Mar 17, 2017 at 12:36
  • 2
    The test doesn't care about the verbal answer, it looks for non verbal, involuntary reactions, pupil changes, blushing, etc.
    – cde
    Commented Mar 17, 2017 at 13:26
  • There's absolutely nothing in the first few questions shown on screen (for either Rachel or Leon) which makes it a dead giveaway that they're replicants. The only reason you're so "sure" is because you - as the viewer - already know the answer outside the movie's universe.
    – Steve-O
    Commented Mar 17, 2017 at 13:27
  • 1
    Sociopaths should beware the Voight-Kampff test! Commented Mar 17, 2017 at 13:49
  • Very good points both from Paulie_D and cde! As for Steve-O, I partially agree, but I did find their responses curious even the first time I saw the movie.
    – forthrin
    Commented Feb 28, 2018 at 16:41

1 Answer 1


From the Blade Runner Wikia, the machine:

...measures contractions of the iris muscle and the presence of invisible airborne particles emitted from the body... [The test] is used primarily by Blade Runners to determine if a suspect is truly human by measuring the degree of his empathic response through carefully worded questions and statements.

So it seems it takes more than a few answers to determine if someone is actually human. A human being could just be bored and answer sarcastically, and a replicant could very well fake answering empathically (up to a certain point), so the combination of the answers and the machine analysis would give a definitive answer.

  • 2
    Regarding the Wiki: the wording of the questions is actually irrelevant, the test is measuring latency in reflexive responses which, in the androids, takes pre-processing. Their reactions are sincere as opposed to simulated, but there was a delay that was measurable. Whether or not they possess empathy is not even important, just that the question provoke emotional responses of any sort. Dick actually takes time to cover this in the book and there is some discussion about the problem of "flattening of affect" in actual humans and how narrow the distinction was becoming.
    – Yorik
    Commented Mar 17, 2017 at 16:32

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .