This is a follow-up from this question over on Movies/TV Stack Exchange.

In my answer to that question, I speculate that it's not a stretch to imagine that sensors sophisticated enough to be capable of detecting life signs (which itself is just a convenient plot device anyway) are also capable of detecting biological sex of those life signs.

Now of course, not all species have the same concept of biological sex, which has been shown in canon. So the sensors are only going to be able to make a best guess, based on some sort of probability determination, which could also include failing to make a determination whatsoever.

I feel like I remember hearing dialog reminiscent of "I'm detecting male life signs", or "I'm detecting female life signs", etc in the past. But it's possible I'm just confusing it with species life signs ("Human" vs "Klingon" life signs, etc).

Prior to Vis à Vis, has it been established in canon that sensors can distinguish, or at least guess at, the biological sex of a life sign? Even an example post that episode would be useful, if we could infer that the technology would have existed in Voyager's time.

Supplementary information from sources like the Technical Manuals would also be acceptable.

  • We have many ways of detecting life signs in the real world, and yet detecting biological sex outside of cultural identifiers is often challenging in humans. In some species of pet reptile, owners often don't know the sex of their pet, as sexing those creatures takes DNA testing. Detecting life signs is way easier than detecting biological sex.
    – prosfilaes
    Sep 8, 2022 at 20:22

2 Answers 2


In a word, yes. We've seen at least one other occasion when the sensors are used to pick out a particular gender

JANEWAY: On screen.

KIM: Showing one life sign, adult Kazon male. He's in critical condition.

JANEWAY: Janeway to Sickbay. Prepare to receive an emergency transport.

VOY: Basics, Part 1

As to the capacity of the sensors, we're told in the TNG Technical Manual that they can ascertain the 'gross' structure of a bioform. I'd assume that if you're particularly close that it's possible that an adult male or female is sufficiently different to allow them to be distinguished.

Remote lifeform analysis. A sophisticated array of charged cluster quark resonance scanners provide detailed biological data across orbital distances. When used in conjunction with optical and chemical analysis sensors, the lifeform analysis software is typically able to extrapolate a bioform's gross structure and deduce the basic chemical composition.

Additionally, we have multiple instances within the Extended Universe novels where the sensors have picked out a particular individual by their sex

"O’Brien looked at Sloan for confirmation. The lean, fair-haired man checked his console, then nodded at O’Brien. “One life sign, Cardassian female. The ship’s clean"

ST - Mirror Universe: Rise Like Lions


It’d been more than five years, but Miles O’Brien worked the Defiant’s console like he hadn’t missed a day. “In the chamber adjacent to you, I’m reading nine Bajorans, three Cardassians, and two humans—one child, one adult female —but I can’t get a lock on them. There’s some kind of force field around them preventing transport.”

Strange New Worlds (2016)

That all being said, we also have a couple of instances where someone has been detected by sensors and it's then assumed by the crew that they're male, for example in VOY: Vis à Vis, but also in TNG: Lower Decks.

TAURIK: Bio readings indicate that passenger's humanoid. Attempting life form identification.

LAFORGE: No one told you to do that, Ensign. Let's just get him aboard safely. There, that should do it.

TNG: Lower Decks

In this case Geordi is making an assumption about the identity of the occupant but doesn't have proof-positive that it's who he thinks it is. You need to refer to them as something, and it's as good one way as the other.

  • One little gap here, maybe: there must also be a premise that the gross structure differences between each species' male and female variants somehow are consistent across a large variety of species. I think there was an episode that explained some pan-spermia kind of origin, but I'm not sure how widely that explains the species' similarities.
    – user152192
    Sep 8, 2022 at 21:26
  • 2
    I believe the "pan-spermia" episode I believe you are referring to is TNG: The Chase, which reveals an common origin species for many life forms in the Milky Way Galaxy.
    – Tronman
    Sep 9, 2022 at 12:13
  • 2
    "Let's just get him aboard safely" could simply be using the common and traditional constructs of the English language referring to a single entity, sex unknown. Unless, of course, there is more to it than was quoted here. Like Scotty telling Kirk, "She can' take anamore, Cap'n", referring to the Enterprise as "she". Of course, it's modern Hollywood writing, so all political correctness is in full effect, so maybe not.
    – FreeMan
    Sep 9, 2022 at 16:37
  • 1
    Regarding Lower Decks, LaForge already knew who was in the escape pod which explains why he referred to the occupant as "him".
    – Xantec
    Sep 10, 2022 at 5:21
  • 1
    Ahhh... thank you. Yes, I was confused by the two.
    – FreeMan
    Sep 10, 2022 at 15:27

I think it is safe to depend on the sensor. I would expect a tricorder can tell you roughly what is nearby and a ship's a near range can identify individuals if necessary.

Note the transcript of Star Trek: The Enterprise Incident (Season 3, Episode 2).

Chekov: You're alive!

Uhura: They said you'd been killed, sir.

Kirk: The report was premature.

Chekov: Captain, your ears. What happened?

Kirk: We'll discuss it later. Mister Sulu, lay in a course for home. Mister Chekov, take the sensors. Mister Spock is still aboard the Romulan flagship. I want his body readings pinpointed and isolated. That was not a request, gentlemen.

Chekov: Aye, sir.


Kirk: Mister Chekov, there's only one Vulcan aboard that ship. He should be easy enough to locate.

Chekov: Romulans and Vulcans appear to read almost exactly alike. There is just a slight difference which. Got him, sir.

Kirk: Feed the co-ordinates to the transporter room on the double. Have them prepare to beam him aboard on my signal.

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