I'm calling bullshit on the title (which, in the hopefully likely event it gets changed, is currently "Hormones Explain Why Girls Like Dolls and Boys Like Trucks"). One study showing a correlation might suggest something worth looking into further but it hardly "explains" anything.
The results with the monkeys are interesting, if both the research and the reporting of it are accurate. However, animal models, while certainly useful indicators, are still just animal models and can't say anything definitive about human biology and psychology.
And as for those studies on young children, it's a mistake to think that just because a child is only a few months old they haven't been exposed to enough cultural influence to skew what they prefer to look at. If just a few of those parents have put a football mobile above their baby boy's cot or decorated their little girl's room with Disney princess wallpaper, that familiarity could easily explain the results.
Do biological differences exist between genders? Absolutely. Are some of those differences driven by ancient evolutionary pressure rather than modern culture? It's a reasonable hypothesis, worth investigating. Have those differences now been explained by a single factor and a few small studies, half of which were on monkeys, and do they just happen to line up with traditional gender stereotypes? You'll have to do a lot better than a Live Science blog that cites nothing but other Live Science blogs to convince me of that.
EDIT: Well, at least the title was changed to better fit the article, even if it still doesn't line up with the actual science.
What are these studies? The metadata studies I've heard about say otherwise. That is, some studies say one thing, other studies say the opposite, and so it's impossible to really conclude anything by choosing a subset of the literature.
They talk about male babies who were sexually reassigned at birth and given female hormones. However many of them decided to reidentify as males later on life, showing that even with female hormones and a female upbringing, it was not enough to make them adopt a female gender identity.
I wouldn't say this is conclusive evidence. But I think it's enough to show that people should keep an open mind about this subject.
Can you show me some of these studies? I just pointed out the problematic lack of citations in the article and your dismissive comment alone isn't going to change my mind. If there's solid evidence one way or the other, I'd be genuinely interested to see it.
And even if they do happen to agree with actual good science, the few studies presented here still don't "explain" anything and this Live Science post is decidedly shonky science reporting (and calling it that is frankly generous).
> If just a few of those parents have put a football mobile above their baby boy's cot or decorated their little girl's room with Disney princess wallpaper, that familiarity could easily explain the results.
This cannot explain how prenatal hormone exposure can predict toy preferences better than "socialized" gender.
Testosterone etc. exposure predicts toy preferences:
I never said it could. It's just something that has to be very well controlled for and this article showed nothing to suggest it was in the studies it sort of cited.
It's entirely possible that the results in those studies you provided are solid. I don't know, I don't have the expertise or the access to go through them thoroughly, let alone run a replication. I would just urge everyone here to keep in mind that, as pointed out very well in aestra's comment above (https://news.ycombinator.com/item?id=7213317), this kind of research is subject to heavy cultural biases, both through the parents and experiments and through poor science reporting in the media.
And, even if it weren't, this Live Science linkbait blog post, the one rapidly climbing the front page of Hacker News with the sensationalist headline, is still uncited bollocks.
"This kind" being the research we've been discussing, which is about socialisation and toy preference. Finger length and other easily-measured physical differences haven't been part of it.
It's briefly mentioned in the article as a possible indicator of toy preference because it correlates well with hormone levels. It clearly wasn't what the research, the discussion, or any of my comments were focusing on.
It's reported in all of the child studies discussed in TFA. Fault the article if you want but "hormones" is in the title, and the whole point of the entire line of research is that it's implausible that prenatal hormone levels could be affected by cultural biases.
The hormone levels are unlikely to be affected by cultural biases but that's not the potential weakness I'm talking about in these studies. It's during the observation, through the eyes of the parents and scientists, of what toys the children are playing with where expectations can affect the results. On top of that, you've got biases affecting what studies get published and which of those then make headlines and get repeated in blog posts like this one.
It's interesting watching the conversation over sex differences take shape. On the one hand, we have a group of people that say even though males and females are biologically different there are NO differences in the way we think or perform. At the other extreme you have the "girls are nurturing, males are war-like" argument. What it really is is a combination of both nature and nurture. The effects of testosterone and estrogen are well known. Brain plasticity is a marvelous thing. Add to that 'developmental windows' where certain behaviors and predilections become our (as in each individual person's) baseline behavior and you have a fantastic spectrum of humanity. Average people will tend more toward stereotypical behavior, because the stereotypes define average. Those at either end of the spectrum may be a hyper stereotype or a stereotype defying unique one-of-a-kind individual. Don't hate it, embrace it.
I found the below links a week ago, just browsing for 'sex differences':
It's always sad to witness this need to flatten things on a space of two extrema. Often it's a complex combination that can't be pinned down neither in space nor time.
It actually oversimplifies all four dimensions, if you can even claim with any surety that there are exactly four dimensions. There are things like "third gender" [1] and there are demisexuals [2] and there are asexuals and so on.
What I like about it is that it's just slightly too big as a concept presentation (though it feels like it isn't) and mostly evokes the recognition that There Are Things You Didn't Know About.
"This study provides unequivocal evidence that sex-biased gene expression in the adult human brain is widespread in terms of both the number of genes and range of brain regions involved. We also show that in some specific cases, molecular differences are likely to have functional consequences relevant to human disease and finally that sex biases in expression may reflect sex-biased gene regulatory structures"
1. It's been the default answer for millenium, and there has only been pushback on this for the last 50-ish years.
2. Because individual variation is often larger than the group variance?
3. (Related to 2.) Because it's often not a useful answer. E.g. Suppose it were proven that women were worse at math than men. Would that change how we taught boys and girls? It almost certainly would, and it almost certainly would be detrimental for the little girls. [note: There is a lot more that could be said here, that I won't say because it would take too long]
These aren't reasons to not do the research, but they are reasons that we should be deeply suspicious of research that satisfies our cultural biases.
There was a law passed in the EU last year, which made it illegal to "discriminate" based on sex when giving out insurance.
So that means you're not allowed to give men cheaper life insurance, even though men live shorter lives than women, and you're not allowed to give women cheaper car insurance because statistically they're safer.
It's complete BS.
I also find it funny how if you tried to argue that homosexuality wasn't something "hard wired", you'd have a pretty tough time. But if you argue "being girlie and liking girlie things" is "hard wired", you have an equally tough time. It's all political "equality".
I think people will look back at this time period as very odd. Trying to pretend everyone is "equal", rather than embracing their differences, strengths and weaknesses.
This is a sensitive topic, like global warming, because it degenerates into politics rather than science. A study value is based on how well it supports preconceived political views.
American slave culture was "scientifically" supported by studies demonstrating the inherent inferiority of the Negro race. (Indeed, that's what race theory is.) This is the same kind of motive behind the search for the "gay gene" or the claim that there are no homosexual non-human animals.
It's obvious there are inherent differences between boys and girls. The question is: how far does it go? People are sensitive to the issue, because other people are liable to read a lot more into whatever scientific evidence exists than is warranted.
For example, it is very typical here on HN for people to say that "there are biological differences between men and women, so maybe women just don't want to work in programming?" Let's admit that the premise is true. Does that mean the proposed corollary is true? No, but that doesn't stop people.
People misuse facts about biological differences between men and women to justify preexisting prejudices. For example, people always point to gender differences to justify why there are fewer women in programming. But even if we accept the premise of stereotypical gender differences, why does that lead to the conclusion that the preference should skew for men? To me, it seems programming is more consistent with what we stereotypically think of as work more suitable for women: involving extensive social coordination, long-term attention to small details, etc. To use the "hunter/gatherer" analogy that is so often trotted out for this purpose: programming is a lot more like working in a group to nurture a field of wheat than setting out on your own to take down a mastodon in a short spurt of bloody combat (well maybe demo coding is like the latter, but shipping quality production software is like the former!)
In summary, people read a lot more into sex differences than are justified by the data by itself, and use that information to validate existing prejudices. That's why people get defensive about such studies and try to put the results into context proactively.
Imagine a scientific study that just said "Scientific justification for social oppression found." In a nutshell, I believe that's why.
It's not even that it's bad for there to be differences between the sexes; what's bad is that some people will inevitable take these studies as justification for their sexist views and attitudes.
But that article concludes that “the Negro” is NOT inferior:
> I have tried to review briefly the important fields in which evidence of Negro inferiority is most likely to be found, if found at all. In no case is the proof conspicuous by its volume---rather the opposite appears true.
I actually wondered how such an article got published as late as 1927. That would explain it. I can go find a better one tonight. More broadly, though, here's a Wikipedia page on the subject:
Glancing through the citations, #33 is "Tiedemann, Friedrich (1836). "On the Brain of the Negro, Compared with that of the European and the Orang-outang" (PDF). Phylosophical Transactions of the Royal Society of London 126."
I'll ask the corollary question: why are people so keen to accept and propagate the wisdom from dodgy studies that tell them that the current status quo is the natural and "right" way for things to be?
Because people are quick to generalize from statistical averages. And because they're more likely to do that when it comes to women and minorities.
Consider the following: Color blindness is generally the result of an X-linked recessive disorder, meaning that it is much, much more likely to occur in men. Yet nobody thinks that one should generalize this to mean that all men (or even a majority of men) have a problem with that or that men as a rule need to be treated with suspicion for all kinds of jobs where that may be an issue.
Now consider mathematical aptitude, which very likely may not be linked to biological sex at all, and if it is, the difference is extremely small (one way or the other). But every single study that shows that men may (may!) have a very small higher aptitude at math quickly gets generalized into meaning that "girls are bad at math" [1], resulting in women being treated as less qualified for STEM jobs/education, etc.
When you've seen this pattern play out too often, you start getting sick of pop science journalism playing up one single study as a definitive result. It's already annoying in general because this is not how science works, but when it's then further used to reinforce cultural stereotypes, it's very frustrating.
Don't get me wrong: There are differences that are linked to biological sex other than reproductive equipment (X-linked disorders are a simple example). But there's a really huge amount of shoddy science and/or uncorroborated studies that pop science journalists publish selectively; they are not the same as a well-corroborated scientific theory such as evolution.
The Larry Summers kerfuffle is a case in point. The problem with Summers' talk was not that it's impossible that men are more likely to be at the extremes of IQ (both good and bad) than women. The problem was that Summers was treating an uncorroborated hypothesis (1) as established science and (2) as an excuse to have fewer women in leadership positions.
To be clear, the hypothesis – and it's an old one [2] –, is not per se unreasonable. It relies on two assumptions: (1) That a large part of IQ-related genes are on the X chromosome and (2) that the lyonization process averages out their effect in women. Which would mean that men are both more likely to have extremely high and extremely low IQ.
Lyonization, or X-inactivation, is what happens if you have a cell with two X chromosomes. Only one of them can be active, so during embryonic development in mammals, one of them for each cell is randomly and independently deactivated (except marsupials, where it's always the paternal X chromosome). This is, for example, why even women who are carriers for hemophilia (an X-linked disorder) are unlikely to suffer from it: while some of their cells have the defect, enough of their cells still produce the necessary clotting factors (though, because the process is random, that may not always be the case).
If the same held for IQ, it would be possible for a similar averaging process to take place there, too. One problem with that hypothesis is that it has not really been conclusively shown so far (it is really, really hard to get rid of the cultural factors to determine very small changes in standard deviation). Another problem is that this is a very simplistic assumption of how IQ is developed. For example, if the model were that simple, then men with Klinefelter's syndrome (who have two X and one Y chromosome in each cell, and whose cells also undergo an X-inactivation process) should experience a similar averaging for their IQ: Instead, Klinefelter's syndrome is held to be responsible for a drop in average IQ of nearly one standard deviation (compared to both men and women). So, it can't be that simple. In fact, while the brain structure for men and women IS different (in ways that we don't fully understand yet), these differences do not seem to relate to the presence or absence of a lyonization process.
So, while the hypothesis is not per se impossible, the president of a research university should really know better than treating it as established science and essentially saying, "it's just normal that we have more male professors".
My favorite part about baby psych studies is how the researcher gets to pick whether "prolonged staring at an object" means "natural affinity for the object" or "surprise at the unexpected object"
The basic premise is that drawing cultural associations cross species is pretty much a no-go; a preference for a "pot" doesn't validate traditional gender roles any more than a preference for a particular color would -- it's more a reflection on our own cultural biases than it is a proof of hard-wired gender roles.
> One study of "toy preferences" in vervet monkeys was ambiguous, since the boy vervets seemed most interested in the plush dog (a toy deemed "neutral") and the girl vervets paid relatively little attention to the doll. The girl vervets did prefer playing with the toy cooking pot, but exactly what they did with it was not reported.
This is the study that the picture at the top of the article is from -- however, the monkey study by Wallen referenced in the article appears to be this one http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2583786/
In one, scientists dressed newborns in gender-neutral clothes and misled adults about their sex. The adults described the "boys" (actually girls) as angry or distressed more often than did adults who thought they were observing girls, and described the "girls" (actually boys) as happy and socially engaged more than adults who knew the babies were boys. Dozens of such disguised-gender experiments have shown that adults perceive baby boys and girls differently, seeing identical behavior through a gender-tinted lens. In another study, mothers estimated how steep a slope their 11-month-olds could crawl down. Moms of boys got it right to within one degree; moms of girls underestimated what their daughters could do by nine degrees, even though there are no differences in the motor skills of infant boys and girls. But that prejudice may cause parents to unconsciously limit their daughter's physical activity. How we perceive children—sociable or remote, physically bold or reticent—shapes how we treat them and therefore what experiences we give them. Since life leaves footprints on the very structure and function of the brain, these various experiences produce sex differences in adult behavior and brains—the result not of innate and inborn nature but of nurture.
For her new book, Pink Brain, Blue Brain: How Small Differences Grow Into Troublesome Gaps—And What We Can Do About It, Eliot immersed herself in hundreds of scientific papers (her bibliography runs 46 pages). Marching through the claims like Sherman through Georgia, she explains that assertions of innate sex differences in the brain are either "blatantly false," "cherry-picked from single studies," or "extrapolated from rodent research" without being confirmed in people. For instance, the idea that the band of fibers connecting the right and left brain is larger in women, supposedly supporting their more "holistic" thinking, is based on a single 1982 study of only 14 brains. Fifty other studies, taken together, found no such sex difference—not in adults, not in newborns. Other baseless claims: that women are hard-wired to read faces and tone of voice, to defuse conflict, and to form deep friendships; and that "girls' brains are wired for communication and boys' for aggression." Eliot's inescapable conclusion: there is "little solid evidence of sex differences in children's brains."
Yet there are differences in adults' brains, and here Eliot is at her most original and persuasive: explaining how they arise from tiny sex differences in infancy. For instance, baby boys are more irritable than girls. That makes parents likely to interact less with their "nonsocial" sons, which could cause the sexes' developmental pathways to diverge. By 4 months of age, boys and girls differ in how much eye contact they make, and differences in sociability, emotional expressivity, and verbal ability—all of which depend on interactions with parents—grow throughout childhood. The message that sons are wired to be nonverbal and emotionally distant thus becomes a self-fulfilling prophecy. The sexes "start out a little bit different" in fussiness, says Eliot, and parents "react differently to them," producing the differences seen in adults.
Those differences also arise from gender conformity. You often see the claim that toy preferences—trucks or dolls—appear so early, they must be innate. But as Eliot points out, 6- and 12-month-olds of both sexes prefer dolls to trucks, according to a host of studies. Children settle into sex-based play preferences only around age 1, which is when they grasp which sex they are, identify strongly with it, and conform to how they see other, usually older, boys or girls behaving. "Preschoolers are already aware of what's acceptable to their peers and what's not," writes Eliot. Those play preferences then snowball, producing brains with different talents.
The disguised gender experiment reminds me of similar ones into whether or not sugar makes children "hyper". It turns out that if you tell parents that their children have had sugar, they're much more likely to describe the kids' behaviour as unruly or hyperactive, even if the kids haven't been given anything at all (http://skeptoid.com/episodes/4142 - the Skeptoid article provides a nice summary and cites a few studies).
The fact is, the human brain isn't anywhere near the objective, rational computer and recorder it likes to think of itself as. We project our expectations on to everything we see, from the facial expressions of a monkey to random clumps of noise in datasets and it's important to keep that in mind whenever you read articles like this one. The information presented in a typical piece of science news has gone through the mental filters of researchers, university PR departments, editors, and a writer before you even start interpreting the first word. Even if every person at every step understands what they're doing and has the best intentions (and isn't, for example, deliberately twisting facts to fit their linkbait article for a pop science blog), that's a lot of room for a convenient narrative to obscure the basic, potentially important facts.
> The sexes "start out a little bit different" in fussiness, says Eliot, and parents "react differently to them," producing the differences seen in adults.
What if human adults are wired to reinforce those different behaviors, for survival purposes? It's known that calories deprivation (the standard for most of human life) gives birth to more men than women, so it's not far fetched to think, e.g., protecting more one gender or stimulating more vicious behavior in another gender can be survival strategy. Any studies on that?
On a deeper level, where does the lines between biology and culture meet? Are those things even possible to dissociate?
I think those are the interesting questions regarding gender studies.
Correct, I mixed it. The point is, it's interesting to know that gender distribution isn't entirely random and can change based on environmental pressure. That also happens with other species, although the mechanisms can be different (e.g., in crocs it's the temperature the eggs are exposed to that determines the sex). Given those gender distribution differences persist, there may be a survival strategy behind.
At some point you need to ask yourself, why the hell do I care? This is so much low-level posturing and image-crafting on the part of anyone who participates. It bespeaks of a self-righteous society with no ability to organize or plan other than whine about the color of the bike shed and other narcissisms of small differences.
The reason people care is that: 1) there are still substantial differences in outcomes between men and women (i.e. 85-95%+ of Fortune 500 CEOs, Congressmen, and Forbes 400 members are men); and 2) people have a habit of extrapolating from "girls like dolls in infancy" to "girls are less suited for certain jobs."
This isn't about self-righteousness, but about bettering ourselves as a society. Within my dad's lifetime, Sandra Day O'Connor graduated third in her class at Stanford, but couldn't get a job at a firm other than as a secretary. Today, such discrimination would be unthinkable. In that short time we've come so far along the path to justice. But we're not there yet, and whenever people point out that we're not there yet by noting the facts in (1), peoples' knee-jerk reaction is: well maybe women don't want to do those things? Understanding what separates the genders at a biological level is crucial in evaluating this argument.
Read the main paper cited in the article by Alexander at Texas A&M in 2002. It says: female MONKEYS prefer COOKING POTS.
Then if you aren't debilitated by laughing read the methods, it's a total piece of shit yet is quoted again and again because it agrees with people's prejudices.
> The researchers studied a group of 17 boys ages 4 to 11 and measured their finger lengths, and took images of their faces. They digitized these images by marking 70 measurement points to compare the face shapes. Analyzing the data on the computer, the researchers were able to see what parts of the face could be linked to digit ratio, and how strongly they were correlated.
It’s a small sample number, too many fuzzy criteria and it looks like an easy set of measurements to cherrypick or find spurious correlations and "explanations".
Anyone interested in gender studies and the current understanding of gender ought to read "Delusions of Gender" by Cordelia Fine. It is a fantastically interesting book.
Do boys actually prefer trucks and balls or do they just not prefer dolls and pick a toy acording to some other quality (complexity of movement?) not taking into account how much the shape resembles human?
Maybe girls would also pick trucks and balls if human shped figures were not available?
The results with the monkeys are interesting, if both the research and the reporting of it are accurate. However, animal models, while certainly useful indicators, are still just animal models and can't say anything definitive about human biology and psychology.
And as for those studies on young children, it's a mistake to think that just because a child is only a few months old they haven't been exposed to enough cultural influence to skew what they prefer to look at. If just a few of those parents have put a football mobile above their baby boy's cot or decorated their little girl's room with Disney princess wallpaper, that familiarity could easily explain the results.
Do biological differences exist between genders? Absolutely. Are some of those differences driven by ancient evolutionary pressure rather than modern culture? It's a reasonable hypothesis, worth investigating. Have those differences now been explained by a single factor and a few small studies, half of which were on monkeys, and do they just happen to line up with traditional gender stereotypes? You'll have to do a lot better than a Live Science blog that cites nothing but other Live Science blogs to convince me of that.
EDIT: Well, at least the title was changed to better fit the article, even if it still doesn't line up with the actual science.