22

I read here about human asexuality, and I cannot figure out if it's real or if people are just making stuff up. Have studies been done about this phenomenon and what explains it?

Jason Plank
  • 3,180
  • 1
  • 26
  • 17
picakhu
  • 3,158
  • 1
  • 22
  • 42
  • 10
    Anecdotally I am asexual, but I have aspergers and ADHD, which may be the cause behind this. – Thomas O Jun 03 '11 at 11:12
  • @Third Yeah, but there's also people who claim they are asexual (don't have interest in sex/romantic relationships, it varies). – Ruben Jun 03 '11 at 11:14
  • 1
    @Ruben The web site talks about or includes people, who are interested in dating but not interested in sex. – ChrisW Jun 03 '11 at 12:21
  • 2
    you should clarificate what sexuality here acutally means: no contact to others, no masturbation at all, no watching of e.g. porn media/voyeurism. I myself rule out that evolution caused besides homo/bi/heterosexuality *biologically* a asexuality state – Werner Schmitt Jun 03 '11 at 18:18
  • Werner, I think it would be the answerer who should clarify it. If you read the website, you will realize that they do not have a clear definition, which to me sounds like an excuse to form a group. – picakhu Jun 03 '11 at 20:04
  • @picakhu yeah how u define religious from going to church - spiritual feelings will multiply the population. Not being able to have a orgasm seems to me crucially, but hard to measure between man - woman, woman at all. It looks more like life-style and personal development dispostion to me – Werner Schmitt Jun 03 '11 at 23:06
  • @Thomas, without trying to be offensive, how can you be sure you are asexual? – picakhu Jun 04 '11 at 01:20
  • 4
    @picakhu Because I have no sexual attraction to either sex. I don't really care about sex. – Thomas O Jun 04 '11 at 08:41
  • 1
    This question needs to be more developed. Have you tried google or done anything to find out? Does if it is real matter to you or affect you in some way? – Chad Sep 05 '12 at 19:56
  • I'd imagine that's a very subjective and relative assessment. If someone thought being a total horn-dog was the norm, they'd maybe identify as asexual, where someone with an equal interest/disinterest in sexual behavior might not view themselves as such. Having said that, I have no reason to doubt that, objectively, such people do exist. – PoloHoleSet Sep 21 '17 at 14:16
  • @picakhu Are you seriously asking if there are people that are not very keen to have sex? Why does this seem like such a surprise to you? –  Sep 25 '17 at 15:30

3 Answers3

28

Yes, but until now only hypotheses on reasons for asexuality are available. Experiments on male gerbils show refused mating with female gerbils, indicating there are epigenetic, prenatal period factors causing diff. sexual orientation/behaviour:

A study on Mongolian gerbils showed that part of a population of male gerbil fetuses that developed between two female fetuses refused to mate, but instead spent almost 50% more time taking care of the young than male gerbils who as fetuses were positioned between two other males. They were also about 30% more likely to stay with a nest when the mother had left. This suggests that, although not perpetuating their own genes, they helped perpetuate their sisters' genes, which has evolution benefits for at least half that family's genes

For humans there has to be distinguished between an asexual lifestyle and sexual excitability/reduced libido, as some self-called asexuals are masturbating and obviously can feel orgasms, better called auto-sexual. Currently from a scientfic point of view there is no clear definition, but above mentioned properties would be obviously crucial. These articles sheds some light on classification of several defintions and genuine causes.

There have been very few studies about asexuality in humans, most of which were about the stereotype that disabled people are made asexual as a result of their condition. One of the only studies that looks at asexuality as a possible orientation was actually a reexamination by Anthony F. Bogaert of a survey of 18,000 British about general sexuality and STDs. 1.05% of the respondents to the survey reported "I have never felt sexually attracted to anyone at all," very close to the 1.11% who responded they were homosexual or bisexual, although more women tended to be the former than the later, and more men tended to be the later than the former. Bogaert noted this asexual group to have poorer health, shorter stature, less body weight, higher attendance at religious services, lower socio-economic status, and asexual women had a later onset of menarche, all when compared to sexual people. Although these are only correlations, they may help form later hypothesis about the cause of asexuality, and whether asexuality is a valid orientation at all. Bogaert suggests some of his own. Perhaps the factors affecting height growth and weight gain also affected a region of the brain vital to sexuality, or education or other resources dependent on socio-economic status are somehow vital in sexual development, or maybe asexuals had fewer "sexual conditioning" experiences growing up (i.e. masturbation) which might also explain the high proportion of women and religious (both groups are less likely to masturbate). Youth, however, was not correlated with asexuality, indicating these individuals were not merely "late bloomers;" asexuals actually tended to be older. Major limitations to the study, besides being merely correlative and not actually about asexuality, include its high non-response bias (30%) and its face-to-face style of interviewing (which may have pressured individuals to alter their answers). However, the study does contain enough correlative evidence to warrant future research in the area. (6)

So phenomenological asexuality seems more to be a female "property", making a epigenetic more plausible than pure genetic causing of asexuality, as one would expect equal distribution.

Differences in human brain structure indicate, that asexuality is also not caused by purely psychological/social development reasons

Since scientists have already noted that the brain of homosexual men is structurally different from that of heterosexual men (cell structure of gay mens' hypothalamus more closely resembles that of a heterosexual female's), that the asexual brain may too be structurally different should not be too easily dismissed. The existence of animal displays of asexuality run contradictory any suggestions that asexuality is a problem caused by psychological issues such as fear of commitment, or conscious/unconscious repression of sexuality, as animals are presumed to be incapable of both, although this rests upon the assumption that asexuality has the same cause in humans and animals

There is also a link between hormone production and libido, chemical castration can force a reduction in libido; some countries use it for pedophiles therapy.

Speculative reasoning:

From an evolutionary point of view one has to ask how likely a pure genetic heredity of a general asexual property is, as humans mainly bear single not several babies and the development help similar to the mentioned gerbil case cannot play a role.

Summary

Asexuality as a mammal phenomenon exists, but currently its not clear how much genetic, epigenetic and post-birth development factors actually contribute to this phenomenon. But current knowledge emphasize factors influencing fundamental brain structure rather than psychologigal/social reasons.

Special cases like genetic caused Asperger, Autism reducing will of physical closeness to other humans show set of difficulties defining and reasoning asexuality on humans.

Mark Rogers
  • 11,324
  • 11
  • 55
  • 71
Werner Schmitt
  • 951
  • 6
  • 15
  • 18
    "as this sort of human would die out immediately form a evolutionary point of view" - Not necessarily. It's a lot more complicated like that. Think Tay-Sachs or sickle cell genes. The gene may very well serve a secondary function which makes it - possibly in concert with the rest of its gene group - ensure the propagation in the **population** even if one of the phenotypal effects is a lack of propagation of a given individual organism. – user5341 Jun 03 '11 at 21:18
  • @DVK the serendip article makes an example of this with gerbils, but not directly. Less mating male garbils having developed between female fetuses, which seems epigenetic, but not genetic disposition to me, as it happens in the development periode of the unborn mammal. Differences between homo/hetero human brain structure are also mentioned. Interesting would be how much of the 1% actually can feel orgasm from my pov. **But sexuality only showing past puberty on humans, makes it to me hardly measurable to proof a genetic disposition** – Werner Schmitt Jun 03 '11 at 23:30
6

It is estimated that ~1% of population is asexual (at least in the UK).

Source: http://articles.cnn.com/2004-10-14/tech/asexual.study_1_sexuality-new-study-new-scientist?_s=PM:TECH (discussing a study by Anthony Bogaert, a psychologist and human sexuality expert at Brock University in St. Catherines, Ontario)

Bogaert's analysis looked at responses to another study in Britain, published in 1994. That study was based on interviews of 18,000 people about their sexual practices.

It offered respondent a list of options. One read: "I have never felt sexually attracted to anyone at all." One percent said they agreed with the statement.

However, it doesn't look like there are a lot - or any - studies on the topic which are more legit (e.g. not based on "have you had sex recently" surveys)

user5341
  • 31,075
  • 8
  • 130
  • 178
  • 6
    It could also mean that 1% of people are willing to write that they have never felt... A survey does not convey truth, it conveys what people are willing to convey. – picakhu Jun 03 '11 at 17:39
  • 1
    @picakhu - correct... that's what I meant by my last paragraph – user5341 Jun 03 '11 at 21:17
-3

Recalling the teasing due to my 'eponymous' syndrome in 7th grade, there is such a thing as Turner Syndrome which leaves a person with a single X chromosome. Such a person would be asexual (although female), as the lack of the second X chromosome somehow inhibits development during puberty.

Peter Turner
  • 1,187
  • 6
  • 27
  • that would mean, he has no physical sex. But how could humans not willing to do sex have evolutionary survived and hand down this property? ;) They die immediatley out. Oxymoron. Correct genetic disposition may be necessary for sexuality, but not sufficient reason, i think the social/psychologically factors prevail here – Werner Schmitt Jun 03 '11 at 18:25
  • @werner, I shouldn't have tried to answer the question, I didn't want to click the link at work (I don't want to click it at home for that matter) – Peter Turner Jun 03 '11 at 18:45
  • 4
    @Werner Not every personal trait has to be hereditary. It can just be a genetic quirk occurring once in a while. – Lagerbaer Jun 03 '11 at 19:02
  • @lagerbaer: kind of epigenetic factors u mean? I know that some animals show homosexuality, but never heard of asexual animals. – Werner Schmitt Jun 03 '11 at 19:25
  • 2
    @Werner, there are many asexual animals. Any animal that does not need sex to reproduce is termed asexual. There are some lizards that are asexual, and all bacteria are asexual. – picakhu Jun 04 '11 at 01:19
  • 1
    @Werner, also see examples of recessive traits like Sickle Cell trait, http://en.wikipedia.org/wiki/Sickle_cell_trait, to see why it may be evolutionarily advantageous to carry around some dangerous genes that might occasionally cause reproductive harm to your children, but normally are good. – Oddthinking Jun 04 '11 at 02:44
  • @picakhu i assumed whe speak on gender divided mammals, i know of asexual reproduction, but dont know gender-divided animal species that show **asexual behaviour**, only homosexual, i clarified this in my main answer @oddthinking thx explained this further with the gerbil case, but for low-rate reproducing humans from an evolutionary pov i find it quite unlikely to establish a asexual population amount of 1% Epigenetic/postnatal reasons seem quite more important to me given the data – Werner Schmitt Jun 04 '11 at 12:34
  • Regarding the notion that asexual organisms would die out. Individual organisms don't die out, they just die. If it is beneficial for the species as a whole to have a certain fraction who are non-reproductive, then the possibility of that phenotype can be carried forward. Are there gender-divided species that show asexual behavior? Sure - The _vast_ majority of honeybees are asexual. I am not an animal behaviorist, but I would imagine that the more interdependence there is among individuals in a species, the more likely it is that a vital role develops for asexual members. – Adam Sep 20 '17 at 18:45
  • That page lists no association between Turner Syndrome and sexual identity. Other pages make it clear that many women with Turner syndrome do have partners and sex, and while lower sexual desire is reported, it's hard to dismiss the other issues of Turner syndrome, including low self-esteem, as a causal relation instead of Turner syndrome directly. – prosfilaes Jul 25 '23 at 18:09