The defend-your-turf area?

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OK, I'm back in Philadelphia and my copy of Louann Brizendine's The Male Brain has arrived. I still haven't had time to read it, but I promised to look up the business about the dorsal premammillary nucleus, so here goes.

You'll recall that Dr. Brizendine's opinion piece at cnn.com ("Love, sex, and the male brain", 3/24/2010) asserted that

Our brains are mostly alike. We are the same species, after all. But the differences can sometimes make it seem like we are worlds apart.

The "defend your turf" area — dorsal premammillary nucleus — is larger in the male brain and contains special circuits to detect territorial challenges by other males. And his amygdala, the alarm system for threats, fear and danger is also larger in men. These brain differences make men more alert than women to potential turf threats.

And Vaughan Bell at Mind Hacks countered that

Male and female humans are indeed the same species, but we are not a species which has a dorsal premammillary nucleus because it's only been identified in the rat.

Furthermore, there is no reliable evidence that amygdala size differs between the sexes in humans and a recent study that looked specifically at this issue found no difference.

His link with respect to amygdala size was specific (J. Brabec et al., "Volumetry of the human amygdala – An anatomical study", Psychiatry Res 2010), and completely contradicted Brizendine's assertion.

But in the case of the dorsal premammillary nucleus, Vaughan could give only a link to a PubMed search, which might perhaps have missed something; so I wondered what specific support Brizendine might have cited in the book for this point.

Indeed, The Male Brain displays the same impressive flourish of endnotes and references as The Female Brain did. It has 135 pages of text, 41 pages of endnotes, and 83 pages of references.  I'll be interested to see whether the notes and references are related to the claims in the text in the same way. In several tedious posts (e.g. herehere and here), I followed up the notes and references behind specific claims in The Female Brain, and found a surprising lack of relevant connection.

I'm not sure how much more of such sleuthing I've got the energy for, but I promised to check out that dorsal premammillary nucleus, so here goes. (Regular readers won't be surprised to learn that this turns out to be another beautiful example of Explanatory Neurophilia.)

The Male Brain's index gives us these page references for dorsal premammillary nucleus:

emotional lives of men and, 110, 111, 170-71
function of, xv


Pages xv-xvi are a picture of "The Male Brain" with ten areas singled out for attention. The header says that

Scientists think of brain areas like the ACC, TPJ, and RCZ ad being "hubs" of brain activation, sending electrical signals to other areas of the brain, causing behaviors to occur or not occur.

The third of the ten key areas (maybe more later on the nine others) is listed this way:

3. DORSAL PREMAMMILLARY NUCLEUS (DPN): The defend-your-turf area, it lies deep inside the hypothalamus and contains the circuitry for a male's instinctive one-upmanship, territorial defense, fear, and aggression. It's larger in males than in females and  contains special circuits to detect territorial challenges by other males, making men more sensitive to potential turf threats.

There are no endnotes for this section. A quick check of the literature reveals that the DPN in rats is involved in a number of things that have nothing to do with intra-species turf defense, e.g. as described in D. Caroline Blanchard et al., "Dorsal premammillary nucleus differentially modulates defensive behaviors induced by different threat stimuli in rats", Neuroscience Letters 345:145-148, 2003:

Lesions of the dorsal premammillary nucleus (PMd) have been reported to produce dramatic reductions in responsivity of rats to a live cat. Such lesions provide a means of analyzing the potentially differential neural systems involved in different defensive behaviors, and the relationship between these systems and concepts such as anxiety. Rats with bilateral electrolytic lesions of the PMd were run in an elevated plus maze (EPM), exposed first to cat odor and then to a live cat, and assessed for postshock freezing and locomotion. PMd lesions produced a dramatic reduction in freezing, avoidance, and stretch attend to the cat odor stimulus, and reduction in freezing, with greater activity, and enhanced stretch approach to cat exposure. However, PMd lesions had minimal effects in the EPM, and postshock freezing scores were unchanged. These results confirm earlier findings of reduced defensiveness of PMd-lesioned rats to a cat, extending the pattern of reduced defensiveness to cat odor stimuli as well, but also suggest that such lesions have few effects on nonolfactory threat stimuli.

In other words, the DPN is involved in rats' (passive) defensive responses to the presence of a cat, or even just to cat odor, but not to other sorts of threats such as the open arms of a maze, or an electric shock to the foot,  where odor is not involved. Thus the DPN is more (and also less) than "the defend-your-turf area" in rats — it responds to predator threats as well as threats from dominant conspecifics, but it's apparently not involved in more active or aggressive forms of defense. Who knows what its homologue's functions are in humans —  but presumably the mediation of instinctive "freezing, avoidance, and stretch" responses to cat odor are not among them.


Page 110 of The Male Brain tells us:

Evolutionary biologists suggest that behaviors like bluffing, posturing, and fighting have evolved to protect males, especially from opponents within their own species. Instinctive male-male competition and hierarchical fighting is driven by both hormones and brain circuits. A special area in the male brain's hypothalamus, the dorsal premammillary nucleus, or DPN, has been discovered, in rats, to contain circuitry for this instinctive one-upmanship. In humans, this one-upmanship and drive for status-seeking is found in men worldwide; it's not just a habit or a cultural tradition but more like a design feature of the male brain.

Here (unlike in the earlier passage) the DPN size business is explicitly linked to research on rat brains, and the connection to human males is made only by implication.

The endnotes (p. 170) give us this:

110 circuitry for this instinctive one-upmanship: Motta 2009 found an area in the male brain's hypothalamus, called the DPN, is activated for instinctive one-upmanship in male rats for territory protection against higher-ranking males.

That's S.C. Motta and M. Goto, "Dissecting the brain's fear system reveals the hypothalamus is critical for responding in subordinate conspecific intruders", PNAS 106(12):4870-75, 2009.

As this study notes, lesion studies had previously established that (in rats) "the site most responsive to predatory threats" (specifically, cats) is "the tiny dorsal premammillary nucleus (PMD)", though other parts of the hypothalamus are also involved. Motta and Goto's contribution:

The experiments reported here were designed to test the hypothesis that the hypothalamus also plays a critical role in the processing and expression of fear responses to another natural danger—a dominant conspecific. For this, hypothalamic activation in response to a predator or a dominant conspecific was compared and it was shown that the PMD is critical for fear expression in both situations, supporting a critical role for the hypothalamus in both responses. Furthermore, despite similar behavior patterns displayed in both threatening situations, predator and dominant conspecific threats are processed by differentiable components of the fear system.

The dependent variable that they looked at was not "activation" in the sense of direct measures of electrical activity, but rather upregulation of the protein product Fos. Interestingly, the PMD (their acronym for the dorsal premammillary nucleus) is the part of the hypothalamus most similarly affected by the threats posed by predators and by dominant conspecifics:

Hypothalamic patterns of neuronal activation are thus strikingly different in animals exposed to a natural predator or a dominant conspecific, although they are not entirely separate. In particular, the PMD was clearly activated in both experimental groups. Careful anatomical inspection indicates, however, that PMD activation patterns are not identical in the 2 groups. Cell count analysis confirms that exposure to a predator or a dominant conspecific massively induces Fos upregulation in the PMD (F3,21 = 129.9, P < 0.0001) and that, whereas predator exposure upregulation is centered in ventrolateral regions of the PMD (PMDvl), upregulation following exposure to a conspecific resident is centered in dorsomedial regions of the nucleus.

So what we have — in male rats — is that the DPN is activated by threats from cats and from dominant conspecifics; and that the (overlapping) effects of these two threats are centered in slightly different parts of the ("tiny") DPN, with the effect of the alpha rats being centered in dorsomedial (as opposed to ventrolateral) regions.

This is a long ways from identifying the DPN, even in rats, as "the defend-your-turf area" that "contains the circuitry for a male's instinctive one-upmanship, territorial defense, fear, and aggression", especially because the rat-response involved (to both predators and dominant conspecifics) is "freezing" or other passive defense reactions, not "boxing" or other aggressive or active defense behaviors, much less the general pattern of "bluffing, posturing, and fighting" that Brizendine attributes to this brain region.

(By the way, I'm also somewhat taken aback by the unsupported assertion that "drive for status-seeking" is "a design feature of the male brain", given years of science and fiction suggesting — if anything — the opposite sexual stereotype. For a survey of one set of issues in the linguistic area, see Elizabeth Gordon, "Sex, speech and stereotypes: Why women use prestige speech forms more than men", Language in Society 26:47-63, 1997. As a crude check on the validity of the cross-cultural concept here, a search on Google Scholar for male status-seeking returns 2,220 items, while a search for female status-seeking returns 2,050 — a random example being "Empirical Tests of Status Consumption: Evidence from Women's Cosmetics".)


Page 111 tells us the story of "Neil", a patient who is anxious about the fact that the president of his firm has decided to retire:

If we could peek back into Neil's brain in this atmosphere of unstable hierarchy, we'd see what was causing his emotional roller-coaster ride. When he thought his prospects for VP looked promising, we'd see his brain area for anticipating rewards activating, and he'd feel good. But when he thought George might get the promotion, we'd see his territoriality circuits in the DPN activating, and he'd feel haunted by the threat of losing face and forfeiting his place in the hierarchy.

Assuming that he's a rat, that is, and that he's "freezing" because a dominant rat has entered his cage. (In fact, Neil's turmoil is caused by the fact that the dominant male is leaving the cage, thus putting the status hierarchy in doubt — Brizendine doesn't cite any studies that show DPN activation in rats as a result of status uncertainty.)

There are no new footnotes for this passage — Brizendine has simply transferred some partly-analogous research from rats, where her interpretation is oversimplified and over-interpreted, to men, where we have no idea whatsoever whether Neil's DPN is playing any special role at all in his turmoil, and certainly no idea whether it's playing a sex-specific role.


Pages 170-171: Page 170 contains the note relevant to page 110, discussed above. Page 171 contains notes to pages 112-113 of the text, none of which say anything whatever about the DPN.


So I'm afraid that Vaughan Bell was right — Louann Brizendine's assertions in her CNN piece about the DPN are based entirely on rat research. I think he might have gone too far in asserting that this structure "[has] only been identified in the rat". At least, if I understand Clifford B. Saper, "Hypothalamus", chapter 17 (pp. 513-550) in The Human Nervous System, 2004, there's a homologous region in the human brain (though I can't figure out for sure whether the same name is used). But there seems to be no evidence as to whether its size is sexually differentiated, and what functions it might have.

In another respect, Vaughan didn't go far enough in calling her claims into question, since even if men and women were exactly like male and female rats in the relevant respects, she'd be elevating to the status of "the defend-your-turf area" a brain region that mediates freezing reactions to cat odor (but not non-smell-related threats) and similar passive reactions to (the smell of?) dominant conspecifics.

In thinking about these things, I recommend taking a look at Geert de Vries & Per Södersten, "Sex differences in the brain: The relation between structure and function", Hormones and Behavior 55(5):589-596, 2009. Their abstract:

In the fifty years since the organizational hypothesis was proposed, many sex differences have been found in behavior as well as structure of the brain that depend on the organizational effects of gonadal hormones early in development. Remarkably, in most cases we do not understand how the two are related. This paper makes the case that overstating the magnitude or constancy of sex differences in behavior and too narrowly interpreting the functional consequences of structural differences are significant roadblocks in resolving this issue.

They close with this observation on "The dual function hypothesis":

In prairie voles, the presence of a sex difference in the brain clearly does not correlate with the size of a sex difference in behavior. The species with the largest sex difference in VP [vasopressin] innervation reported to date shows some of the least conspicuous sex differences in social behavior. Apparently, the sex difference in VP can cause as well as prevent sex difference in social behavior. Because there is no reason that this dual function is VP's prerogative, we suggested that in general sex differences in brain structure may cause as well as prevent sex differences in specific behaviors or centrally regulated functions. This dual function hypothesis is perfectly testable. To take the VP system as an example, one would predict in the former case, that blocking VP neurotransmission would blunt or eliminate sex differences and in the latter case that the same treatment would cause a sex difference that wasn't there before. In fact, such tests have already been done; treatment with a VP antagonist blocked social recognition memory in male but not in female rats, thereby creating a new sex difference. Related to this, the V1a receptor knock-out mouse has a behavioral phenotype in males but not in females, exactly what one would predict for a system that is more important for a function in one sex than in the other.



22 Comments

  1. Doctor Science said,

    March 29, 2010 @ 2:06 pm

    I'm baffled. Is this supposed to prove that human females aren't territorial or alert to threats? Does she have no memory of high school?

    [(myl) The ideology here is that females are all about communication and cooperation. Brizendine's earlier book said that the female brain is "[a] machine … built for connection." [p. 21] "That's the main job of the girl brain, and that's what it drives a female to do from birth. This is the result of millennia of genetic and evolutionary hardwiring… [S]ince you're smaller, you probably need to band with other females to fend off attacks from a ticked-off caveman…"

    See here and here for more. And then there's stuff like this.]

  2. Sili said,

    March 29, 2010 @ 2:25 pm

    By the way, I'm also somewhat taken aback by the unsupported assertion

    Really?

    After all the digging and investigating you've done to show that Brizendine is bogus, you still manage to be surprised when she continues to be so? This is no more than common quotemining in the style of cdesignproponentsists, anti-vaxxers and climatedenialists everywhere. They call read from the same book.

    What I'd like to know if to what extent LB suffers from crank magnetism. What other untenable notions does she subscribe to?

    Thank you, as always, for exposing yourself to teh stoopeed so that we need not do so, ourselves.

  3. quodlibet said,

    March 29, 2010 @ 3:21 pm

    Where is the dorsal premammillary nucleus in relation to the crockus?

    [(myl) Well, the crockus is apparently the thin little royal-blue area here, which is part of the frontal lobes of the cerebral cortex:

    The dorsal premammillary nucleus is part of the hypothalamus, and so (assuming that it has a homologue in humans) it would be a small part of the structure shown here:

    They're not all that far away in Talairach coordinates, but they're part of quite different structures...]

  4. Rubrick said,

    March 29, 2010 @ 3:50 pm

    Not for the first time, I'm staggered by the sheer amount of work you manage to do when you are apparently, by your own lights, slacking.

    Being one of your grad students must be a humbling (and perhaps terrifying?) experience.

  5. Oskar said,

    March 29, 2010 @ 4:38 pm

    This is a real public service that you're doing, the debunkification of the pseude-neuroscience of "sex differences". These claims pop up frequently in media, and I've heard numerous friends parrot essentially the same claims, and it's good to know that that there's very little actual science behind it.

    Keep it up! Y

  6. Ken Grabach said,

    March 29, 2010 @ 4:51 pm

    It seems to me that there are but little or perhaps subtle differences either semantically or neurologically speaking, between the supposedly female trait of 'connecting' and the supposedly male trait of defending territory for the group or family unit. They sound to me like different brands of the same goods. And in female rats or other mammals, can't the female do a pretty good job of defending when the nest, den, brood, or whatever, or her young ones away from the nest or den? The sterotype here is don't come between momma bear and her cubs.

  7. Blake Stacey said,

    March 29, 2010 @ 5:19 pm

    That's the main job of the girl brain, and that's what it drives a female to do from birth. This is the result of millennia of genetic and evolutionary hardwiring.

    For some reason, Brizendine keeps reminding me of Eyes Wide Shut.

    "Millions of years of evolution, right? Right? Men have to stick it in every place they can, but for women… women it is just about security and commitment and whatever the fuck else!"

    "A little oversimplified, Alice, but yes, something like that."

    "If. You. Men. Only. Knew!"

  8. Jerry Friedman said,

    March 29, 2010 @ 5:43 pm

    How dare this WOMAN intrude on the study of the male brain?! It's always been reserved for men and it always should be! Does she think it's a coincidence that brain is an anagram for BRIAN, a MAN's name??! She needs to get back where she belongs!! And there's nothing territorial about us, either!

  9. Jean-Sébastien Girard said,

    March 29, 2010 @ 9:32 pm

    @Jerry

    There's one male body part that's significantly less complex than the brain, yet we understand fairly little about it. Apparently we males are kinda queasy about studying the penis' anatomy. Maybe that explain why we still have no idea how ejaculations work :p

  10. Tal said,

    March 30, 2010 @ 12:41 am

    Mark, since you've got the book at hand, could you maybe clarify what the mysterious "sexual pursuit area" that's supposed to be 2.5 times larger in men is? Google won't tell, and I'm dying to know…

    [(myl) That's Male Brain area #1, from page xv:

    1. MEDIAL PREOPTIC AREA (MPOA): This is the area for sexual pursuit, found in the hypothalamus, and it is 2.5 times larger in the male. Men need it to start an erection.

    A quick Google Scholar search suggests that it's another area known mostly through rat studies, though songbirds are also involved, as well as sheep. In rats, it also mediates (some aspects of?) maternal behavior. As far as I can tell, the erection business is known only from lesion studies in rats (and rams?). In humans, the homologous brain region would apparently be called (one of?) the "interstitial nucleir of the anterior hypothalamus" (INAH1-4).

    According to William Byne et al., "The Interstitial Nuclei of the Human Anterior Hypothalamus: An Investigation of Variation with Sex, Sexual Orientation, and HIV Status", Hormones and Behavior 40:86–92, 2001:

    The interstitial nuclei of the human anterior hypothalamus (INAH1–4) have been considered candidates for homology with the sexually dimorphic nucleus of the preoptic area of the rat. Volumetric sexual dimorphism has been described
    for three of these nuclei (INAH1–3), and INAH3 has been reported to be smaller in homosexual than heterosexual men. The current study measured the INAH in Nissl-stained coronal sections in autopsy material from 34 presumed heterosexual men (24 HIV2 and 10 HIV1), 34 presumed heterosexual women (25 HIV2 and 9 HIV1), and 14 HIV1 homosexual men. HIV status significantly influenced the volume of INAH1 (8% larger in HIV1 heterosexual men and women relative to HIV2 individuals), but no other INAH. INAH3 contained significantly more neurons and occupied a greater volume in presumed heterosexual males than females. No sex difference in volume was detected for any other INAH. No sexual variation in neuronal size or density was observed in any INAH. Although there was a trend for INAH3 to occupy a smaller volume in homosexual men than in heterosexual men, there was no difference in the number of neurons within the nucleus based on sexual orientation.

    I guess we can conclude from this that INAH1 causes HIV infection :-)...
    The mean (human) sex difference in INAH3 in this study was about 60%, and the difference corrected for overall brain weight was aout 37%, rather than the 250% mentioned by Brizendine (her numbers, again, appear to come from rats).]

  11. B. W. said,

    March 30, 2010 @ 1:47 am

    Thank you for once more debunking pseudo-neuroscience. Even reading the quotes is painful – I would never manage to actually read a whole chapter, it makes me want to bang my head on the desk.

    Just as a small correction: The Blanchard rat paper actually says that lesions of the PMd produce a reduction in freezing both to cat odor and live cat exposure, but not to non-predator-related threats. So they extended previous findings on reactions to live cats and now show that reactions to cat odor are similarly affected by the lesion. It seems to me that the rat papers refer to a very specialized function in predator fear. How she can change predators into conspecifics and fear/freezing into bluffing and posturing is beyond me…

    [(myl) Sorry, I checked the Blanchard paper more carefully and corrected my discussion -- they found that PMd lesions didn't affect reactions to the open arms of mazes and to electric shocks to the foot, but did affect "freezing" reactions to cats and to dominant conspecifics.]

  12. Acilius said,

    March 30, 2010 @ 8:31 am

    I'm with Rubrick. This post would be an excellent week's work for most people; the fact that it's just one blog post among many posted by someone who is also shouldering substantial professional responsibilities is simply incredible.

  13. 4ndyman said,

    March 30, 2010 @ 9:04 am

    It irks me that Brizendine keeps using size as an indicator of importance. When you finally do get around to reading, please check whether her size comparisons are in absolute size or are size relative to height or total body weigh or something.

    Aren't men's organs on average larger than women's organs in all cases? Does that apply to the brain as well? It might be true that the average male DPN is absolutely larger than the female DPN simply because males have a larger overall brain.

    [(myl) As far as I've been able to tell, no one has ever measured human DPNs. In fact, it remains a bit unclear to me whether humans have DPNs, as such, at all, or just areas of the hypothalamus that may be homologous, perhaps called by some other name.

    In the case of one of Brizendine's other "Male Brain" areas, the Medial Preoptic Area (MPOA), I tracked down a reference that makes it clear that the homology in human brains is still somewhat unsettled, but appears to connect to regions that are called "interstitial nuclei of the anterior hypothalamus", or INAH1-4. It appears that INAH3 is about 60% larger on average in human males, or about 37% larger relative to total brain volume. (Though I find these numbers hard to square with other reports on human sex differences in brain volume, which tend to be around 13% on average as I recall...)

    Someone with more time, patience, or knowledge may be able to figure out whether there's a consensus about what region of the human hypothalamus is homologous to the dorsal premammillary nucleus, and if so, what it's called. On p. 527 of Clifford B. Saper, "Hypothalamus" (chapter 17 (pp. 513-550) in The Human Nervous System, 2004), there's a long paragraph about structures in the rat hypothalamus, which mentions the dorsal premammillary nuclei along with 15-20 other substructures. (This is the only place in the 38-page chapter where the DPN is mentioned.) The next paragraph says that "In general, much less is know about intrinsic hypothalamic connections in humans or monkeys, although what is known suggests that they are similar to those documented in rats."

    I note that the Wikipedia's table of hypothalamic nuclei (which appears to apply to monkeys) lacks anything with a name corresponding to "dorsal premammillary nucleus".]

    Regardless, hasn't it been proven that larger brain size doesn't equate to greater cognitive power? After all, an elephant's brain weighs 4 times that of a human.

    [(myl) Whenever sexual dimorphism in the human brain is discussed, the numbers are always presented both in absolute terms and in relation to brain weight or brain volume, for just this reason. However, in the case of the dorsolateral premammillary nucleus, as far as I can tell, no one has ever measured the homologous area in humans (whatever it's called), so the point is moot.]

  14. Rubrick said,

    March 30, 2010 @ 4:54 pm

    Wait a minute — I just figured it out. Mark Lieberman is obviously a linguistic Bourbaki! It's the only explanation.

  15. not my leg said,

    March 30, 2010 @ 5:21 pm

    4ndyman,

    If I recall correctly (and wikipedia supports this, although without citation, so who knows) absolute brain size (weight) between species does not correlate to intelligence, but brain weight as a proportion of total weight does correlate to intelligence. At least, it does assuming the comparison is interspecies, I don't know that the same could be generalized to an intraspecies comparison as is being made here.

    Wikipedia says (with a citation) that correlations in humans have been found ranging from 0 to .6. Most studies have a result of .3 or .4. Without knowing the number of subjects involved it is impossible to know whether that is statistically significant or not (the citation is to another study citing these numbers).

    [(myl) Generally (for a given group of related species) log brain weight vs. log body weight is roughly linear. Deviations from this expected relationship are sometimes quantified via a number called the "encephalization index" or "encephalization quotient" (though similar terms may simply refer to the brain-weight/body-weight ratio.) Here's a typical plot of the basic relationship for a variety of primate species:

    (For some context, see the lecture notes I took the plot from.)

    And here's a plot showing that (in general) insectivorous bats such a Mormoopidae, Vespertilionidae, and Emballonuridae have a lower degree of encephalization than specifies feeding on nectar, fruit, or blood, such as the Phyllostomidae:


    (Plot from H Stephan et al., "Encephalisationsgrad südamerikanischer Fledermäuse und Makromophologie ihrer Gehirne", Gegenbaurs Morph Jahrb 123:151-179, reprinted in Gerhard Neuweiler, The Biology of Bats, 2000.]

  16. Doctor Science said,

    March 30, 2010 @ 8:49 pm

    Since you're smaller, you probably need to band with other females to fend off attacks from a ticked-off caveman…

    This is, of course, complete balderdash both from an evolutionary-biology POV, and from any observation of women's behavior. But I think it is quite revealing about what Brizendine is actually doing.

    One of the most reliable ways for a woman to get security and protection is to make herself necessary to one man or to the Boy's Team, and from that position of safety drive off — or diss, or insult — other women.

    In modern times, I think of it as the Phyllis Schlafly Strategy: "all *other* women are feeble, dependent creatures unworthy of money or political power. You can believe me, guys, I'm just selflessly helping you, as a selfless real woman should! Pay no attention to the money, power, and influence it gets me." The position of Official Female Misogynist is frequently very well-rewarded, in both money and in male attention.

    Brizendine is a pseudo-scientific Schlafly. She's got a niche, making herself look taller by making other women look shorter, and it seems to be working out pretty well for her, financially speaking.

  17. Nathan Myers said,

    March 30, 2010 @ 9:52 pm

    Buckaroo Banzai: "You can check your anatomy all you want, and even though there may be normal variation, when you get right down to it, this far inside the head it all looks the same. No, no, no, no, no. Don't tug on that! You never know what it might be attached to."

  18. [citation needed]» Blog Archive » elsewhere on the net said,

    March 31, 2010 @ 3:01 am

    [...] The Male Brain with second one, now that he's actually got his hands on a copy. Verdict: the book is still terrible. Mark was also kind enough to answer my question about what the mysterious "sexual pursuit [...]

  19. David said,

    March 31, 2010 @ 8:35 am

    Unfortunately by making sweeping claims about brain differences, Brizendine continues to drive a wedge between a real concern about boys and girls. Some will read her book and completely buy-in; while others will claim, after reading this site and others, that the idea and basis of sex differences is completely wrong headed. The trouble is, there really is something happening with boys and girls in school. Regardless of the debate about sex differences, the data is pretty strong that there are achievement, behavioral, and social gaps between how the educational process affects or impacts boys and girls. The Center on Educational Policy provided the most recent information on this. So, my take is to try to find some way to meet the needs of boys and girls because of the gaps that seem to exist for both boys and girls in different ways. And, when turning to skeptics, such as Lise Eliot, what common grounds can we find to help enlighten what educators do.

  20. Helen said,

    April 4, 2010 @ 1:54 pm

    Why assume the problem is necessarily in the educational environment? Why couldn't it be the effects of growing up in a sexist environment in general?

  21. NT males: do you think most girls, in general, are pretty boring? - Page 13 - PersonalityCafe said,

    April 19, 2010 @ 7:29 am

    [...] of disagreement. Surely you cannot be unaware of that? And that there is endless foolishness like this lying around. Most of those books and news articles, again, massively overstate what tiny trends [...]

  22. Wednesday Round Up #112 « Neuroanthropology said,

    April 21, 2010 @ 9:41 am

    [...] Liberman, The Defend-Your-Turf Area? All about the dorsal premammillary nucleus. And what our language casts upon [...]

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