Brain Gender in Tweens

July 22nd, 2009 by Pelle Billing

About a week ago, featured an interesting article about how the brains of tween girls and boys react to potential social interaction. First of all, it’s interesting to note that the journalist is still trying to be politically correct, and tiptoeing around the facts:

Only in the past few years have scientists been able to use imaging technology to look inside men’s and women’s heads to investigate whether those stereotypical gender differences have roots in the brain. No concrete results have emerged from these studies yet

I suppose you could say that no concrete results have emerged, if you’re expecting a complete brain manual for both sexes and all individuals. However, if by concrete results you mean results that clearly demonstrate that men and women have brains that function differently, and that are structured differently, then yes – concrete results have emerged.

Interestingly enough, after firing off that politically correct introduction, the author proceeds with an almost biologically deterministic statement about the research report on tweens and social interactions:

a new functional magnetic resonance imaging (fMRI) study of children offers at least one explanation for some common tween social behaviors: girls are hardwired to care about one-on-one relationships with their BFFs (best friends forever), while the brains of boys are more attuned to group dynamics and competition with other boys.

I believe that biology is a very real factor in creating gender differences, but it’s important to remember that behaviors are usually a combination of biology, culture and free will. Claiming that biology only is responsible is usually a premature claim, in a world where we still need to work out the details around how biology, culture and free will affect gendered behavior – not to mention how these three factors continously interact.

This caveat aside, the research report becomes yet another piece in the puzzle of the emerging knowledge base around biological brain differences between the sexes:

The results suggest that as girls progress from early puberty to late adolescence, certain regions of their brains become more active when they face a potential social interaction. Specifically, when an older girl anticipates meeting someone new — someone she believes will be interested in her — her nucleus accumbens (which is associated with reward and motivation), hypothalamus (associated with hormone secretion), hippocampus (associated with social learning) and insula (associated with subjective feelings) all become more active. By contrast, boys in the same situation show no such increase in activity in these areas. In fact, the activity in their insula actually declines.

Finally, the author even offers us a potential explanation that is grounded in evolutionary psychology:

Perhaps it’s evidence that evolution has programmed boys to compete within large groups, so they can learn to eliminate rivals for women — and that girls have been programmed to judge, one-on-one, who would be the most protective father for offspring.

As always, it’s good to remember that evolutionary psychology is still speculatory in many ways, especially when it’s used in the context of explaining a research report that wasn’t in itself explicitly examining the validity of an evolutionary psychology claim.

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6 Responses to “Brain Gender in Tweens”

  1. Alexander Says:

    Hey. Nice blog etc. Biology and culture seem to be inevitable influences on us humans. But free will? I’d like to see a scientifically plausible and relevant definition of that concept, please.

  2. Clabbe Says:


  3. Gilesy Says:

    I’d basically substitute that word ‘freewill’ for individual desires, preferences etc and it makes a bit more sense. Even if its just a fudging of innate and social stuff no doubt – did you choose your preferences? No you choose things because they happen to be your preferences for a variety of reasons – then when you put in the idea of ’cause and effect’ being unbreakable (uncaused effect anyone? if so post answer off for Nobel prize) no choice can truely be free.

    I’d like to point out that I believe you used the term biological as a synonym for ‘innate’ – I’m sure you’re well aware that biology is the medium that is affected by both innate and social factors – Theres also a lot of social-heavy explanations that would expect the same results from those biological findings. If a child is told stories about prince charming making their life a dream and being happy with the right people, and that happens to be a female stereotype perpetuated by culture – then bam back to the ‘now where the f*ck does this go on the nature-nurture continuum???

    That said, some really solid behavioural evidence for generally innate sex differences just after childbirth (about as low a social element as you can get), plus brain sizes, grey to white matter ratio stuff like that.

  4. Gilesy Says:

    I’d also like to point out that the ‘girls do this, guys do this in mating’ evolutionary explanation is only support that brains have to at least be flexible enough to adopt these social pressures / tactics. If societies change at all, its the flexible ones that will do best, not those ‘hard-wired’ into a particular strategy (same evolutionary benefit too when the behaviour of the ‘flexible one’ and ‘hard-wired one’ would be identical in that strategy).

    People tend to quickly forget that the brain is rediculously flexible in virtually everything it does. Especially when people use evolutionary explanations as sure-fire ways of establishing innate determinism for stereotypical behaviours (no doubt with some sort of justification for political or social views lurking no far behind).

  5. Pelle Billing Says:

    I’m aware that free will is a controversial term. If you don’t like it, you can substitute it for personal level of development, personality, etc (similar to what Gilesy suggests).

    Thanks for pointing me to the article!

    Yes, innate is a more precise word than biological. However, in layman’s terms “biological” represents “innate”. I like precise words though, so I’ll think about your feedback.

    I agree that the brain is very flexible; in fact, it would be difficult for such a complex system to not be flexible. However, that doesn’t mean that there aren’t hardwired parts too, it simply means that the brain has the potential to transcend those hardwired parts, if the environment demands it.

  6. Gilesy Says:

    Quick point on the ‘layman defence’ – this article is about fMRI research (hardly a layman area), specifically activity located within biological locations – the concept of biological as innate used in this circumstance, cuts out 1/2 the debate before its even begun.

    I believe the interchangable use of biological and innate is extremely damaging to discussion and beliefs in all spheres and so we should raise our consciousness to that (and not perpetuate any mistaken ‘layman’ predicates). I am very glad you can see my point there.

    Imagine what would happen if two branches of the media reported these findings, one using that assumption, one not. Its not difficult to see that assumption having massive political implications – so there is a real importance (beyond truth-seeking) to challenging this idea.

    Finally, hard-wired areas, certain ones (such as sensory, abstract thought, ability to create representations etc) are the supports on which flexibility can stand – in the same way that learning a language allows you to express far more complex thoughts for less energy (as opposed to someone who has autism for instance). Both of these feed into each other, complex thoughts get names and get lobbed back into language as concepts – and increasing use of these hard-wired areas allows an individual to develop a more nuanced final flexibility in their thoughts and behaviours.