Ahumanoid (/ˈhjuːmənɔɪd/; from Englishhuman and-oid "resembling") is a non-human entity with human form or characteristics. By the 20th century, the term came to describe fossils which weremorphologically similar, but not identical, to those of thehuman skeleton.[1]
Although this usage was common in the sciences for much of the 20th century, it is now considered rare.[1] More generally, the term can refer to anything with distinctly human characteristics or adaptations, such as possessingopposableanteriorforelimb-appendages (i.e. thumbs),visible spectrum-binocular vision (i.e. having two eyes), orbiomechanicplantigrade-bipedalism (i.e. the ability to walk on heels andmetatarsals in an upright position). Humanoids may also includehuman-animal hybrids (where each cell has partly human and partly animal genetic contents) andhuman-animal chimeras (where some cells are human and some cells are animal in origin).[2]Science fiction media frequently present sentient extraterrestrial lifeforms as humanoid as a byproduct ofconvergent evolution.
Humanoid characters are defined by their human-like physical characteristics and forms, which can vary. These characters may appear entirely human, predominantly human-like (e.g., Saiyans fromDragon Ball Z), predominantly human-like (e.g., Martians fromDC Comics), or they may possess general non-human traits while still having human-like physical characteristics (e.g.,human-likePokémon,ThunderCats characters, various characters fromThe Amazing World of Gumball). In the latter case, they often overlap withanthropomorphic characters, with humanoid characters being a sort of sub-category to anthropomorphism, specifically regarding physical characteristics.
Although there are no known humanoid species outside the genusHomo, the theory ofconvergent evolution speculates that different species may evolve similar traits, and in the case of a humanoid these traits may includeintelligence andbipedalism and other humanoidskeletal changes, as a result of similarevolutionary pressures. American psychologist andDinosaur intelligence theoristHarry Jerison suggested the possibility of sapient dinosaurs. In a 1978 presentation at theAmerican Psychological Association, he speculated thatdromiceiomimus could have evolved into a highly intelligent species like human beings.[3] In his book,Wonderful Life,Stephen Jay Gould argues if the tape of life were re-wound and played back, life would have taken a very different course.[4]Simon Conway Morris counters this argument, arguing that convergence is a dominant force in evolution and that since the same environmental and physical constraints act on all life, there is an "optimum" body plan that life will inevitably evolve toward, with evolution bound to stumble upon intelligence, a trait ofprimates,crows, anddolphins, at some point.[5]
In 1982,Dale Russell, curator of vertebrate fossils at theNational Museum of Canada inOttawa, conjectured a possible evolutionary path that might have been taken by the dinosaurTroodon had it not perished in theCretaceous–Paleogene extinction event 66 million years ago, suggesting that it could have evolved into intelligent beings similar in body plan to humans, becoming ahumanoid of dinosaur origin. Over geologic time, Russell noted that there had been a steady increase in theencephalization quotient or EQ (the relative brain weight when compared to other species with the same body weight) among the dinosaurs.[6] Russell had discovered the first Troodontid skull, and noted that, while its EQ was low compared to humans, it was six times higher than that of other dinosaurs. If the trend inTroodon evolution had continued to the present, its brain case could by now measure 1,100 cm3; comparable to that of a human.Troodontids had semi-manipulative fingers, able to grasp and hold objects to a certain degree, and binocular vision.[7]
Russell proposed that this "Dinosauroid", like most dinosaurs of the troodontid family, would have had large eyes and three fingers on each hand, one of which would have been partiallyopposed. As with most modern reptiles (and birds), he conceived of its genitalia as internal. Russell speculated that it would have required a navel, as a placenta aids the development of a large brain case. However, it would not have possessed mammary glands and would have fed its young, as birds do, on regurgitated food. He speculated that its language would have sounded somewhat likebird song.[7][8]
Russell's thought experiment has been met with criticism from other paleontologists since the 1980s, many of whom point out that his Dinosauroid is overly anthropomorphic.Gregory S. Paul (1988) andThomas R. Holtz, Jr., consider it "suspiciously human" (Paul, 1988) andDarren Naish has argued that a large-brained, highly intelligent troodontid would retain a more standard theropod body plan, with a horizontal posture and long tail, and would probably manipulate objects with the snout and feet in the manner of a bird, rather than with human-like "hands".[8] (Although bipedal dinosaurs often dohavehands, if they don't turn them into wings.)
A humanoid robot is a robot that is based on the general structure of a human, such as a robot that walks on two legs and has an upper torso, or a robot that has two arms, two legs and a head. A humanoid robot does not necessarily look convincingly like a real person, for example, theASIMO humanoid robot has a helmet instead of a face.
Anandroid (male) orgynoid (female) is a humanoid robot designed to look as much like a real person as possible, although these words are frequently perceived to be synonymous with a humanoid.
While there are many humanoid robots in fictional stories, some realhumanoid robots have been developed since the 1990s, and some real human-looking android robots have been developed since 2002.
Similarly to robots, virtualavatars may also be called humanoid when resembling humans.
Deities are often imagined inhuman shape (also known as "anthropotheism"), sometimes ashybrids (especially thegods ofAncient Egyptian religion). A fragment by the Greek poetXenophanes describes this tendency,
...Men make gods in their own image; those of theEthiopians are black and narrow-nosed, those of theThracians have blue eyes and red hair.[9]
Inanimism in general, the spirits innate in certain objects (like the Greeknymphs) are typically depicted in human shape, e.g. spirits of trees (Dryads), of the woodlands (the hybridfauns), of wells or waterways (Nereids,Necks), etc.
With regard toextraterrestrials in fiction, the term humanoid is most commonly used to refer toalien beings with abody plan that is generally like that of a human, including upright stance andbipedalism, as well as intelligence.
In much ofscience fiction, humanoid aliens are abundant.[10] One explanation is that authors use the only example of intelligent life that they know, humans. In live-action television and films, using humanoid aliens makes it easier to cast human actors to portray alien characters. A study by the zoologist Sam Levin suggests that aliens might indeed resemble humans, given that they are presumably subject tonatural selection. Levin argues that this can be expected to produce a hierarchy of cooperating systems that make up anyorganism.[11] Luis Villazon points out that animals that move necessarily have a front and a back;as with animals on Earth, sense organs tend to gather at the front as they encounter stimuli there,forming a head. Legs reduce friction, and with legs, bilateral symmetry makes coordination easier. Sentient organisms will, Villazon argues, likely use tools, in which case they need hands and at least two other limbs to stand on. In short, a generally humanoid shape is likely, though octopus- or starfish-like bodies are also possible.[12] An opposing view is given by Mike Wall, who argues that intelligent extraterrestrials able to contact Humans would most likely have reached a phase allowing them to develop themselves into machines.[13]
Several in-universe explanations have been offered for the abundance of humanoids. One of the more common is that the humanoids in the story have evolved on anEarth-like planet or natural satellite, totally independently from Humans onEarth. However, some works have offered alternative explanations:
InStar Trek, the explanation is given that a primordial humanoid civilization, theAncient humanoids, seeded theMilky Way Galaxy with genetically engineered cells to guide the evolution of life on a multitude of worlds toward a humanoid form.[14] In the television seriesStargate SG-1, theJaffa are explained as being a hundred-thousand year offshoot of humanity bred by theGoa'uld to suit their purposes, hence their almost-human appearance and physiology, while many other "alien" characters are actually the descendants of human-slaves who were removed from Earth by the Goa'uld. Any humans isolated on multiple planets after 100k+ years of adaptations would most certainly seem "alien" to Earthlings. Similarly, in its spin-off showStargate Atlantis, the explanation offered for the humanoid appearance of theWraith is that the Wraith evolved from a parasite which incorporated humanDNA into its owngenome after feeding on humans, giving the Wraith their present form.[15]
In the field ofufology,humanoid refers to any of the claimedextraterrestrials which abduct human victims, such as theGreys,[16] theReptilians,[17]Nordics, andMartians.
In fantasy settings the termhumanoid is used to refer to a human-like fantastical creature, such as adwarf,elf,gnome,halfling,goblin,troll,orc or anogre, andBigfoot. In some cases, such as older versions of the gameDungeons & Dragons, a distinction is made betweendemi-humans, which are relatively similar to humans, and humanoids, which exhibit larger differences from humans. Animals that are humanoid are also shown in fantasy. Humanoids are also used in some old horror movies, for example inCreature From the Black Lagoon, made in 1954 byJack Arnold.