# Aside from humanoid, what shape would otherworldly sentient life likely have? **URL:** \ **Category:** In My Humble Opinion\ **Created:** [August 3, 2012, 9:59am UTC](https://boards.straightdope.com/t/aside-from-humanoid-what-shape-would-otherworldly-sentient-life-likely-have/630276 "2012-08-03T09:59:42Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![s0meguy](https://avatars.discourse-cdn.com/v4/letter/s/a3d4f5/32.png) [@s0meguy](https://boards.straightdope.com/u/s0meguy)\ **Post date:** [August 3, 2012, 9:59am UTC](https://boards.straightdope.com/t/aside-from-humanoid-what-shape-would-otherworldly-sentient-life-likely-have/630276/1 "2012-08-03T09:59:42Z")
I guess the question can be rephrased as: what shape of creature would be the most likely to evolve intelligence on the level of humans, aside from humanoid? Or do you think that any shape as long as they are large enough to support some kind of brain (and have the other necessary infrastructure) would be just as likely to develop such intelligence, given the right evolutionary stimulus? Please give your reasons. Just throw some ideas around, they don’t have to be well thought out. Do you think this shape of sentient life could be more common than the humanoid shape? Would sentient life likely be biped? or on 4 legs? Would it likely have a similar system of organs (as in, they perform pretty much the same functions)? Thank you. ---
**Author:** ![jackdavinci](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jackdavinci/32/3259_2.png) [@jackdavinci](https://boards.straightdope.com/u/jackdavinci)\ **Post date:** [August 3, 2012, 10:09am UTC](https://boards.straightdope.com/t/aside-from-humanoid-what-shape-would-otherworldly-sentient-life-likely-have/630276/2 "2012-08-03T10:09:27Z")
I think they need to use tools or at least be in the habit of manipulating their environment, to stimulate advanced cognition, so having something like opposable fingers is likely. Perhaps tentacles or pincers or fancy mouth parts of some kind would do. Otherwise it’s a crapshoot. ---
**Author:** ![grude](https://avatars.discourse-cdn.com/v4/letter/g/e47774/32.png) [@grude](https://boards.straightdope.com/u/grude)\ **Post date:** [August 3, 2012, 10:13am UTC](https://boards.straightdope.com/t/aside-from-humanoid-what-shape-would-otherworldly-sentient-life-likely-have/630276/3 "2012-08-03T10:13:33Z")
There is no real answer to this question without more detail, like what kind of planet and environment they inhabit. Also I think if first contact ever does happen we’ll rethink what it means to be sentient, imagine a species that has only chemical receptors for sense organs and remains in constant contact with other by the release and uptake of chemical signals constantly. ---
**Author:** ![s0meguy](https://avatars.discourse-cdn.com/v4/letter/s/a3d4f5/32.png) [@s0meguy](https://boards.straightdope.com/u/s0meguy)\ **Post date:** [August 3, 2012, 10:19am UTC](https://boards.straightdope.com/t/aside-from-humanoid-what-shape-would-otherworldly-sentient-life-likely-have/630276/4 "2012-08-03T10:19:05Z")
> [@grude](#): > > There is no real answer to this question without more detail, like what kind of planet and environment they inhabit. > > Also I think if first contact ever does happen we’ll rethink what it means to be sentient, imagine a species that has only chemical receptors for sense organs and remains in constant contact with other by the release and uptake of chemical signals constantly. But the question is what sentient life would be more likely, which is also influenced by what type of planet environment would be most likely to support complex life (assume for the sake of this question Earth-like because we don’t know any better). What shapes would they be most likely to come in, aside from humanoid, and why? ---
**Author:** ![Blake](https://avatars.discourse-cdn.com/v4/letter/b/a9a28c/32.png) [@Blake](https://boards.straightdope.com/u/Blake)\ **Post date:** [August 3, 2012, 10:23am UTC](https://boards.straightdope.com/t/aside-from-humanoid-what-shape-would-otherworldly-sentient-life-likely-have/630276/5 "2012-08-03T10:23:02Z")
Utterly impossible to answer, beyond what **jackdavinci** has already added. ---
**Author:** ![s0meguy](https://avatars.discourse-cdn.com/v4/letter/s/a3d4f5/32.png) [@s0meguy](https://boards.straightdope.com/u/s0meguy)\ **Post date:** [August 3, 2012, 10:25am UTC](https://boards.straightdope.com/t/aside-from-humanoid-what-shape-would-otherworldly-sentient-life-likely-have/630276/6 "2012-08-03T10:25:07Z")
> [@Blake](#): > > Utterly impossible to answer, beyond what **jackdavinci** has already added. Just speculate. People are too afraid to be wrong. Obviously I’m not asking for a factual answer, because that would be impossible. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [August 3, 2012, 10:28am UTC](https://boards.straightdope.com/t/aside-from-humanoid-what-shape-would-otherworldly-sentient-life-likely-have/630276/7 "2012-08-03T10:28:25Z")
Size is important. It’s difficult to sustain fires and smelt metals at smaller-than-human scales (at least in Earth-like conditions) ---
**Author:** ![samclem](https://avatars.discourse-cdn.com/v4/letter/s/a9a28c/32.png) [@samclem](https://boards.straightdope.com/u/samclem)\ **Post date:** [August 3, 2012, 11:13am UTC](https://boards.straightdope.com/t/aside-from-humanoid-what-shape-would-otherworldly-sentient-life-likely-have/630276/8 "2012-08-03T11:13:21Z")
No factual answer possible. Moved from General Questions to IMHO. **samclem** ---
**Author:** ![s0meguy](https://avatars.discourse-cdn.com/v4/letter/s/a3d4f5/32.png) [@s0meguy](https://boards.straightdope.com/u/s0meguy)\ **Post date:** [August 3, 2012, 11:39am UTC](https://boards.straightdope.com/t/aside-from-humanoid-what-shape-would-otherworldly-sentient-life-likely-have/630276/9 "2012-08-03T11:39:52Z")
> [@samclem](#): > > No factual answer possible. Moved from General Questions to IMHO. > > **samclem** I disagree, I think a factual answer is possible. Using deductive reasoning and what we currently know about planets and life on Earth, a factual answer can be made, it just might be wrong because there is more information out there that we haven’t discovered yet. But that is the case with many of the “General Questions”. ---
**Author:** ![monavis](https://avatars.discourse-cdn.com/v4/letter/m/e0b2c6/32.png) [@monavis](https://boards.straightdope.com/u/monavis)\ **Post date:** [August 3, 2012, 11:48am UTC](https://boards.straightdope.com/t/aside-from-humanoid-what-shape-would-otherworldly-sentient-life-likely-have/630276/10 "2012-08-03T11:48:18Z")
> [@s0meguy](#): > > I guess the question can be rephrased as: what shape of creature would be the most likely to evolve intelligence on the level of humans, aside from humanoid? > > Or do you think that any shape as long as they are large enough to support some kind of brain (and have the other necessary infrastructure) would be just as likely to develop such intelligence, given the right evolutionary stimulus? > > Please give your reasons. Just throw some ideas around, they don’t have to be well thought out. > > Do you think this shape of sentient life could be more common than the humanoid shape? > > Would sentient life likely be biped? or on 4 legs? Would it likely have a similar system of organs (as in, they perform pretty much the same functions)? > > Thank you. I have often wondered how another humoid being would come about, evolution to a humanoid in their world would not have happened, if a coment hadn’t struck here and made it possible for humans to evolve. The odds to me seem so great if not impossible. I do think that there may be some form of life on some other planet, but wonder if they would have the same thinking as we humans do,or if maybe other beings had visited earth and helped people evolve. I am sure not a scientist,nor do I have the brain to figure it out.Would it start with the same type of organism, or would it be necessary? ---
**Author:** ![Telemark](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/telemark/32/372_2.png) [@Telemark](https://boards.straightdope.com/u/Telemark)\ **Post date:** [August 3, 2012, 11:57am UTC](https://boards.straightdope.com/t/aside-from-humanoid-what-shape-would-otherworldly-sentient-life-likely-have/630276/11 "2012-08-03T11:57:51Z")
> [@s0meguy](#): > > I disagree, I think a factual answer is possible. How would you demonstrate that your answer is correct? There’s not shame in asking questions that have no factual answer, but when you are guessing it doesn’t go in GQ. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [August 3, 2012, 12:26pm UTC](https://boards.straightdope.com/t/aside-from-humanoid-what-shape-would-otherworldly-sentient-life-likely-have/630276/12 "2012-08-03T12:26:45Z")
This is quite an interesting question, One way to tackle it is to ask: _what are the alternatives to any of our own features?_ But to start off, let’s look at what we mean by ‘humanoid’; to me, this includes: [ul] [li]External bilateral symmetry[/li][li]Bipedal, upright[/li][li]Bimanual, dextrous[/li][li]Primary sense cluster on top[/li][li]Binocular vision[/li][li]Ingestion at one end, excretion at the other[/li][/ul] Then we can take each of these broad strokes and ask: what else could it have been? Binocular vision is one way to have depth perception - but another way to do this is to have one eye and wave it around on a tentacle, judging depth by parallax instead. Binocular vision also permits a broadened field of view, but this is also possible with something like the wraparound compound eyes found on some Arthropods - including some species of (extinct) Trilobites. So instead of having a face with two eyes in it, an organism could have a motile eyestalk with a single eye on it, or could have multiple eyes of this kind… …but… a damaged eye is a significant survival risk, so it might actually be better to keep the eyes recessed in a hardened enclosure… and we’re heading back towards having a humanoid head again. ---
**Author:** ![Acid\_Lamp](https://avatars.discourse-cdn.com/v4/letter/a/d6d6ee/32.png) [@Acid\_Lamp](https://boards.straightdope.com/u/Acid_Lamp)\ **Post date:** [August 3, 2012, 12:38pm UTC](https://boards.straightdope.com/t/aside-from-humanoid-what-shape-would-otherworldly-sentient-life-likely-have/630276/13 "2012-08-03T12:38:36Z")
> [@monavis](#): > > I have often wondered how another humoid being would come about, evolution to a humanoid in their world would not have happened, if a coment hadn’t struck here and made it possible for humans to evolve. The odds to me seem so great if not impossible. I do think that there may be some form of life on some other planet, but wonder if they would have the same thinking as we humans do,or if maybe other beings had visited earth and helped people evolve. I am sure not a scientist,nor do I have the brain to figure it out.Would it start with the same type of organism, or would it be necessary? Not necessarily. We already had bipedal beings with a single pair of grasping arms, and bilateral symmetry; theropod dinosaurs. That is all you need for “humanoid.” Given earth similar conditions, and that life has bilateral, rather than radial symmetry, It is likely that the lifeforms will consist of parts that are identifiable to us. That isn’t to say that they would be the Star-Trek type that look just like humans but with funny foreheads, but they ought to consist of parts we can identify easily. They will need to be mobile to gather resources, so they must have some way of moving about. They will need to be able to manipulate objects and create tools so they must have (at least) semi- dedicated appendages for that. It is likely that they will possess a sensory set similar to our own, though there are many other senses that would also be on the table. Intelligence necessitates communication of some type, and since we don’t know of any real exhibition of telepathy, we can make a reasonable guess that their communication must be based on some other physical sense. Efficient communication is conducted at distances safe from physical interaction (to allow the organism a chance to “decide” about the input it has received) so it should take a form we can notice, (possibly only with the help of mechanical aids) like visual, aural, or electromagnetic. Pheromonal communication is rather limited, so I would not expect it to be a primary form of communication. ---
**Author:** ![Keeve](https://avatars.discourse-cdn.com/v4/letter/k/f07891/32.png) [@Keeve](https://boards.straightdope.com/u/Keeve)\ **Post date:** [August 3, 2012, 12:41pm UTC](https://boards.straightdope.com/t/aside-from-humanoid-what-shape-would-otherworldly-sentient-life-likely-have/630276/14 "2012-08-03T12:41:26Z")
We also have to clarify what is meant by “sentient”. Are dogs and chimps sentient? Bees and ants? Where do you draw the line? Dolphins don’t have opposable thumbs. ---
**Author:** ![BMalion](https://avatars.discourse-cdn.com/v4/letter/b/e274bd/32.png) [@BMalion](https://boards.straightdope.com/u/BMalion)\ **Post date:** [August 3, 2012, 12:41pm UTC](https://boards.straightdope.com/t/aside-from-humanoid-what-shape-would-otherworldly-sentient-life-likely-have/630276/15 "2012-08-03T12:41:29Z")
Just read some Larry Niven. ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [August 3, 2012, 12:48pm UTC](https://boards.straightdope.com/t/aside-from-humanoid-what-shape-would-otherworldly-sentient-life-likely-have/630276/16 "2012-08-03T12:48:16Z")
First and foremost we need to define what is being meant by “sentience” in this context. The word literally just means having a subjective perceptual experience (having “qualia”) and does not imply human scale intelligence but usually in these contexts we are also discussing something about consciousness and/or intelligence. The conversations get muddled quickly however because individual posters are sometimes meaning different things. As for having subjective perceptual experiences, I have no reason to believe my dog does not have one. Let’s start though with assuming we are broadly discussing consciousness more broadly including being a problem solving entity with self-awareness and intentionality. > [@jackdavinci](#): > > I think they need to use tools or at least be in the habit of manipulating their environment … I would broaden this out. “Manipulating their environment” may not be the physical environment. Sentience is not technology. There is a substantial debate among scientists over whether the main driver of human cognitive development was tool use (and communication about how to use and create tools) or social interactions including manipulating other social players (which requires the development of deception and of deception-detection). There was in fact [this recent tidbit](http://rsbl.royalsocietypublishing.org/content/early/2012/06/26/rsbl.2012.0435.full) about the role of sociality and “cheating” in cephalopod cognitive development. > [@](#): > > These observations suggest that cuttlefish cognition is sophisticated: they recognize when only one rival male is present and only then elect to employ a deceptive display. Courting males may refrain from such displays if they detect more than one rival male perhaps because there is a high probability that their deception will be discovered, the tactic will fail and they will be punished by larger males. Furthermore, even in the presence of a single rival, males must orient themselves accurately between the female and the rival male during mate guarding for the deception tactic to be effective. … Tactical intraspecific deception in animals is commonly associated with higher vertebrates because of its link with sophisticated cognitive function [2]. For example, females and subordinate male gorillas move out of sight of the dominant male to mate surreptitiously. In primates, deception correlates with neocortex size [17] and tactical deception is considered one of many telltale signs of the cognitive demands associated with living in complex social groups [18]. Brain sizes of cephalopods are more comparable to those of vertebrates than of other molluscs [19] and, although brain size per se has yet to be correlated with deception in cephalopods, this trait is indicative of highly complex behaviour that includes mimicry, tool use and tactical deception [20–22]. We suggest that social complexity may be one of the driving forces behind the evolution and development of tactical deception and advanced cognitive behaviour in cephalopods in general, which parallels that of primates. Would we recognize another sentient entity if their sentience was not like ours? After all we only accept that other humans are sentient because we know we are and they each look and behave like us and report the same sorts of experiences … Are whales sentient? On what basis do you make that assessment? Is the group mind of a bee hive or a large ant colony (which possesses tremendous problem solving ability) sentient? Again, how would we know? Back to the specifics of the op - I would argue that much of cognitive development responding to tool use but that high level sentience, in the sense of having self-awareness and placing that self within a broader environment being thought about, is driven more by social complexity, driven by the need to have a mind but to have a theory about what is going on in the minds of others, their mental states, emotions, and possible plans. (See “Theory of Mind.”) The entity that needs to do that could look like anything, could be a hive mind even … ---
**Author:** ![Acid\_Lamp](https://avatars.discourse-cdn.com/v4/letter/a/d6d6ee/32.png) [@Acid\_Lamp](https://boards.straightdope.com/u/Acid_Lamp)\ **Post date:** [August 3, 2012, 12:53pm UTC](https://boards.straightdope.com/t/aside-from-humanoid-what-shape-would-otherworldly-sentient-life-likely-have/630276/17 "2012-08-03T12:53:25Z")
> [@Keeve](#): > > We also have to clarify what is meant by “sentient”. Are dogs and chimps sentient? Bees and ants? Where do you draw the line? Dolphins don’t have opposable thumbs. This a problem of language and ability to understand inter-species communication. It is likely that many animals might be “proto-sentient”, and that other species we recognize as intelligent but are optimized for their environment, like dolphins and elephants might have a sentience that is radically different from our own. Some of the things that we recognize as necessary may not be needed for them due to biology. Perhaps we should limit ourselves to beings that can reliably be observed to be roughly analogous to our own species. They make _complex_ tools at a minimum, live in groups, alter their environment to build homes, etc.. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [August 3, 2012, 1:32pm UTC](https://boards.straightdope.com/t/aside-from-humanoid-what-shape-would-otherworldly-sentient-life-likely-have/630276/18 "2012-08-03T13:32:45Z")
Even if we can come up with some list of traits that alien people (whatever we mean by “people”), there are still myriad forms those traits could take. Consider “manipulative organs”, for instance (what we use hands for): Even among species which have structures homologous to our hands, we’ve got several who instead use their tails as manipulative organs, several which use their hind limbs instead of their front ones, one that’s evolved an entirely new set of “fingers” not homologous to ours at the extremity of their limbs, and a couple that use their _nose_, of all things, as manipulative organs. If that’s the kind of diversity we can get on just _one_ planet, and among species which are relatively closely related, just think what you could get on multiple planets, with species completely unrelated to each other. ---
**Author:** ![s0meguy](https://avatars.discourse-cdn.com/v4/letter/s/a3d4f5/32.png) [@s0meguy](https://boards.straightdope.com/u/s0meguy)\ **Post date:** [August 3, 2012, 4:11pm UTC](https://boards.straightdope.com/t/aside-from-humanoid-what-shape-would-otherworldly-sentient-life-likely-have/630276/19 "2012-08-03T16:11:49Z")
Perhaps answering this question would give some pointers: What would be the ideal shape for humans? I was thinking; is there a land mammal with more than 4 limbs? If there are, it must be extremely rare. Perhaps elephants have 5 limbs, but only because using their mouth isn’t very practical and it can’t grab anything with its feet. Maybe this indicates that 4 arms and 2 legs would not exist a lot, as this kind of trait would be filtered out by evolution. I’m guessing because it’s a waste of energy to maintain those limbs, if they’re not that useful, which could be why we don’t have tails anymore. So I suppose they’d have to evolve on a planet where that is useful. What kind of circumstances could those be? What about more than 2 eyes? Also very rare. ---
**Author:** ![Acid\_Lamp](https://avatars.discourse-cdn.com/v4/letter/a/d6d6ee/32.png) [@Acid\_Lamp](https://boards.straightdope.com/u/Acid_Lamp)\ **Post date:** [August 3, 2012, 4:41pm UTC](https://boards.straightdope.com/t/aside-from-humanoid-what-shape-would-otherworldly-sentient-life-likely-have/630276/20 "2012-08-03T16:41:02Z")
> [@s0meguy](#): > > Maybe this indicates that 4 arms and 2 legs would not exist a lot, as this kind of trait would be filtered out by evolution. I’m guessing because it’s a waste of energy to maintain those limbs, if they’re not that useful, which could be why we don’t have tails anymore. Not necessarily. This has a lot to do with the limb arrangement of our early ancestors, rather than a \*finite \*evolutionary pressure. If our early fish ancestors had six limbs, we probably would have as well. Four is not inherently superiour to six, just merely what was more successful at one crucial point in our early evolutionary history. [Next page](https://boards.straightdope.com/t/aside-from-humanoid-what-shape-would-otherworldly-sentient-life-likely-have/630276.md?page=2)