Homosexuals Are Smart?

By Neuroskeptic | April 11, 2012 6:11 am

Evolutionary psychologist Satoshi Kanazawa has never been far from controversy. When he’s not having his blog cancelled for saying black women are unattractive, he’s arguing that some nations just aren’t smart enough to be monogamous.

Given which, his latest work, saying that gay people are smarter on average, is probably his most politically correct paper in years, strange as that may sound.

In three large population surveys (USA’s AddHealth and GSS, UK’s NCDS), Kanazawa found a small positive correlation between estimated IQ and self-reported homosexual behaviour or identity.

Now I’m not sure what to make of this. He controlled for confounds such as race, religion and political orientation (and those correlations are interesting in themselves), but you can never measure and correct for everything in a study like this.

Kanazawa interprets all this in terms of the Savanna hypothesis, essentially the idea that intelligence allows us to transcend our evolutionary programming (according to which we ought to all be straight, amongst many other things) –

The Savanna-IQ Interaction Hypothesis (Kanazawa, 2010a), implies that the human brain’s dif?culty with evolutionarily novel stimuli may interact with general intelligence, such that more intelligent individuals have less dif?culty with [evolutionarily novel] stimuli than less intelligent individuals…

Evolutionarily novel entities that more intelligent individuals are better able to comprehend and deal with may include ideas and lifestyles that form the basis of their preferences and values; it would be dif?cult for individuals to prefer or value something that they cannot truly comprehend…

However, it could be that in America and the UK today, smarter people tend to end up in the kind of social circles where being gay is (for whatever reason) more acceptable.

My main problem with this is that the effects are very small. For example, in the AddHealth study, IQ in childhood was correlated with later adult sexual identity with a coefficent of 0.013… but the association of homosexuality with political attitude (liberalism) of 0.613, 60 times as high. (Edit: But these are unstandardized regression coefficients, so they cannot be directly compared. The coefficients represent the change in homosexuality per ‘point’ change in the other variable, but IQ varies more than political orientation, because political attitudes were measured on a 5 point scale in AddHealth but IQ has a mean of 100 points. Multiplying by the SD of the variables in question, which is one way to correct for this, gives a coefficient for IQ of 0.202 and for political attitude is 0.468, so intelligence is not as far behind politics as as I thought. Thanks to a reader for pointing that out and apologies for the error.)

The Savanna hypothesis is all very well, but does it predict such small effects? Isn’t there a point where very weak evidence in favor of a theory actually becomes evidence against it…?

ResearchBlogging.orgKanazawa, S. (2012). Intelligence and Homosexuality Journal of Biosocial Science, 1-29 DOI: 10.1017/S0021932011000769

  • http://www.blogger.com/profile/08010555869208208621 The Neurocritic

    Did you notice the abstracts of the two Kanazawa papers in Journal of Biosocial Science?

    “The origin of preferences and values is an unresolved theoretical problem in behavioural sciences. The Savanna-IQ Interaction Hypothesis, derived from the Savanna Principle and a theory of the evolution of general intelligence, suggests that more intelligent individuals are more likely to acquire and espouse evolutionarily novel preferences and values than less intelligent individuals, but general intelligence has no effect on the acquisition and espousal of evolutionarily familiar preferences and values.”


    “The origin of values and preferences is an unresolved theoretical question in behavioural and social sciences. The Savanna-IQ Interaction Hypothesis, derived from the Savanna Principle and a theory of the evolution of general intelligence, suggests that more intelligent individuals may be more likely to acquire and espouse evolutionarily novel values and preferences (such as liberalism and atheism and, for men, sexual exclusivity) than less intelligent individuals, but that general intelligence may have no effect on the acquisition and espousal of evolutionarily familiar values.”


    Finally, what did you make of this?

    “It is instructive to note that, while education and childhood intelligence are significantly positively correlated (r=0.3320, p<0.0001, n=14,429), education and childhood intelligence have opposite associations with adult sexual identity; more intelligent individuals are more likely to identify themselves to be homosexual, while more educated individuals are less likely to do so."

  • ivana Fulli MD

    The Neurocritic,

    Many thanks for what you wrote here.

    The “scientist” might not be worth discussing his little pieces of work if the subject was not so fascinating.

    My intuitive take on Homosexuality and intelligence is that when homosexuals are feeling and behaving different as children in a given society, they are often bullied in the school system, in their “traditional” and natural circles of friends if they live in a village and so on.

    Some escape the bullying and look for social acceptance or even social revenge by trying to excel in whatever opportunity is on offer.

    It makes them serious hard worker and serious competitors be it in the fashion industry or at their PhDs or whatever.

    But the ones who are too much bullied or challenged become under-achievers and IQ tests -or whatever measures of intelligence- are rich in false negative results from subjects od study who appear less intelligent than they are.

    The later are also the ones who will not put themselves out as homosexuals as often as the high achievers in traditionnal societies.

  • Ivana Fulli MD

    What is for sure though is that Italians politicians political correctness about homosexuality is rarely smart:

    Take recently , Domenico Scilipoti, MP:

    “Molte donne sono costrette in un corpo da uomo, intendevo quello quando parlavo di “patologia”, e dobbiamo risolverlo. Poi c'è l'omosessuale che lo fa per scelta.


    (“A lot of women are obliged to live in a man body, this is what I was thinking about when I spoke about “pathology”, and we shall get out of it. Besides is the homosexual who does it by choice.”)

  • http://aethelreadtheunread.wordpress.com aethelreadtheunread

    Fascinating post.

    As a layman, I'm struggling to understand why an attraction to a person of one's own sex would be considered 'evolutionarily novel' but an attraction to a person of the opposite sex wouldn't. It would seem to me – and I may well have missed something very obvious – that the same things that make opposite-sex attraction possible (sexual dimorphism, the capacity to experience sexual attraction) also make same-sex attraction possible, and that there are no real grounds for presuming that same-sex attraction is more 'novel' in evolutionary terms than opposite-sex attraction. I wonder if Kanazawa has succumbed to a tendency I've noticed amongst some other people who do research into sexual orientation – namely to think of heterosexuality as archetypal and homosexuality a deviation from it, rather than thinking of them both as parallel phenomena.

    Insofar as this layman understands, it's also not at all clear that evolutionary programming ought to lead to us all being straight. It's possible that, in evolutionary terms, my role as a gay man is to facilitate the rearing of the offspring of my kin (who are genetically very similar to me) rather than reducing the reproductive effectiveness of us all by producing offspring of my own to compete for scarce resources. This possibility correlates very nicely with the observation that the number of older brothers a man has influences the likelihood that he will be gay. ( http://www.pnas.org/content/103/28/10771.full )

  • Kibo

    I'd just like to say that I'm gay, therefore this study is true.

  • http://www.blogger.com/profile/06647064768789308157 Neuroskeptic

    Neurocritic: Hmm. Well spotted. about the abstracts. That's weird… still, there's no law against it…

    I really don't know what to make of the education finding. It seems counterintuitive.

  • Ivana Fulli MD

    /// I really don't know what to make of the education finding. It seems counterintuitive./// 13 April 2012 19:20

    In my sad clinical experience too many highly intelligent people have a hard time to enter and stay in the education system. In the French parents association of gifted children thay 50% of highly gifted children are highschool drop out( but I never was convinced of the validity of those precise affirmations).

    What is also sad and certain is that in France poor immigrants'children are more likely to burn cars for fun and sell streetdrugs than to be PhD candidates not because they lack intelligence but because the school system is a failure at giving them the help they need.

    My point is : On average life is still harder for the homosexual young people even in Western societies and I would expect this to interfere with their school curriculum and the education they get. In conseqence thhomosexuals will be less educed than their intelligence would have desserved had the society be fair and the school system efficient.

  • Ivana Fulli MD


    Actually one can also consider that for Darwin's evolution of species theory the newer the better (better adapted to the new conditions) if one didn't suspect that homosexuality might have been as old as humanity.

    Anyway Darwin's theory applies to the species and to a scale of time who do not relate with a human life course and the benefit for society of any person living should not measured by the production of offspring-unless you are an economist working on how to pay health care and retirement pension fot poor old people.

    Just as an example ot two , I think the homosexuals in the USA have been a significant force for making the American male (no matter how sexually oriented) dress better and in making the food more healthy and interesting (I remember a time where a vegetarian had nothing interesting to eat in the USA at the restaurants )etc…

    On the health front the homosexuals have been determinant in the fight against AIDS and in the winning of a little power to clients about research directions and treatment availability etc…

    For Paris city the homosexuals are very pleasant and money spending tourists.They help our economy a great deal.

    Beware that it also applies to hetero or bisexual women and men who do not want children and modern western society put pressure on those people in an unfair way.

    PS: I do not admire much the evolution psychologists – my intuition is that they do not understand what that theory is about.( The theory itself is the work of a genius and a hard working genius at that and has very few holes in it.)

  • http://www.blogger.com/profile/12835021279108929371 Callum J Hackett

    It's surely worth noting that even if this unlikely effect were valid, Kanazawa's explanation of it is dire. His assumptions about “evolutionarily novel” behaviours represent quite childish understandings of human sexuality and biology in general. The notion of it being “novel” seems to be a terse and obtuse way of declaring it maladaptive, or at least not selected for in the first place. Instead, as any fool should be able to tell, the prevalence of homosexuality both within and without our species is testament to its evolutionary importance despite the fact that we may not fully understand its function. To call it “novel” as though it is on par with the invention of reading or using a microwave is disingenuous and terribly uninformed.

  • http://www.blogger.com/profile/10656881172906444719 Meng Hu

    Neurocritic :
    “… more intelligent individuals are more likely to identify themselves to be homosexual, while more educated individuals are less likely to do so.”

    I haven't read the paper, but I think he wanted to say “at a given education level, a higher IQ increases the likelihood to identify themselves to be homosexual”

    For example, this is what I obtained from the GSS :
    But as you can see, I did not control for IQ.

  • http://www.blogger.com/profile/10759148682366911818 Paul V

    I was curious. No sexual correlation.

    “On theWeschler Adult Intelligence Scale (WAIS), Willmott and Bri-erley (1984) found that gay men scored higher than heterosex-ualmenandwomenontheVerbalIQsubscale(andlowerthanheterosexual men, but equal to heterosexual women, on thePerformance IQ subscale; there were no differences in Full-Scale IQ). Sanders and Wright (1997) reported higher verbalthan performance IQ in homosexual men compared to hetero-sexualmen(again,nodifferentfromwomenandnodifferencesinFull-ScaleIQ).Onestudyinadults(usingtheWAIS)reportedno differences in IQ performance (Tuttle & Pillard,1991).Finally,onestudyinfeminineboysusedtheWechslerPreschoolandPrimaryScaleofIntelligence (WPPSI)ortheWechslerIntelligence Scale for Children-Revised (WISC-R), dependingon the child’s age, and reported no differences in Full-Scale IQperformance(Finegan,Zucker,Bradley,&Doering,1982).”

  • SnarketinaJones

    Unclear from the article: does this study look at men who have sex with men, or only at people who officially identify as gay? Because those are two very different groups.

    One of the major lessons of the HIV epidemic is that only about half of men who have sex with men (MSM) actually identify as gay. So if you are talking about “gay men” you are only talking about half of men who have sex with men.

    It would stand to reason that the people who are willing to publicly identify as gay would have more social capital overall, including a high IQ. But that doesn’t mean that all gay people have higher IQs — just that the gay people with higher IQs are the ones who are more likely to acknowledge and identify as gay people.



No brain. No gain.

About Neuroskeptic

Neuroskeptic is a British neuroscientist who takes a skeptical look at his own field, and beyond. His blog offers a look at the latest developments in neuroscience, psychiatry and psychology through a critical lens.


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