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How Can There Still Be a Sex Difference, Even When There Is No Sex Difference?

psychologytoday.com

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Re: How Can There Still Be a Sex Difference, Even When There Is No Sex Difference?

#51
post #6

Earlier quoted context omitted.

Why are you trying to lecture a troll? To put it another way: m8, u 8 the b8

Oh it's not really for them . See, if you don't state the obvious that such people are disgusting little twerps it gets brought up as an example of the things evil tech industry people really think but won't say.

So you're basically putting on a show for people who are spectacularly wrong about the obvious and loud about it?

Don't feed the trolls. That includes the people who think anyone who disagrees with them is a .ist, .phobic troll.

Re: How Can There Still Be a Sex Difference, Even When There Is No Sex Difference?

#52
post #19
post #9

Is it generally accepted in the relevant scientific communities that male IQ's exhibit more variance than female IQ's? I imagine this type of thing would be easy to verify via e.g. standardized test scores.

One usual citation is Global Sex Differences in Test Score Variability (DOI: 10.1126/science.1162573). It uses standardized test scores. I quote findings below. Remarks inside parentheses are mine. "The third column in table S1, reports the estimated male/female variance ratios with standard errors in parentheses. In all but five countries (There are 41 countries) we can reject the hypothesis that the variance ratio…

Reading the supplementary material (since that isn't paywalled) I not that these are not IQ tests, but results from mathematics and reading comprehension tests.

I also found this little thing that implies that the score distributions aren't symmetric (I think):

"There is no clear pattern in the male to female ratios at the bottom 5% of the math distribution. This ratio is different from one in only 15 countries but in some countries it is larger than one and in others smaller. On the other hand, at the top 5% the ratio of boys to girls is larger than one in 35 countries with the highest estimated ratio in Korea (2.55). In these 35 countries, boys are clearly over-represented at the top end of the math distribution. The quantile differences at 5th and 95th quantiles confirm the same finding, with no clear pattern at the 5th quantile but positive and significant differences in all but five countries at the 95th quantile. "

Doing a quick test, I took some random normal numbers with variance ratio 1.4, and found that the variance ratio is not very sensitive to if I calculate it using the full sample, the bottom half or the top half. In other words, for a normal distribution the reported ratios for the 5th and 95th quantile should be the same within the errors, but this is never the case for mathematics so the scores simply aren't normal.

Re: How Can There Still Be a Sex Difference, Even When There Is No Sex Difference?

#53
post #19
post #9

Is it generally accepted in the relevant scientific communities that male IQ's exhibit more variance than female IQ's? I imagine this type of thing would be easy to verify via e.g. standardized test scores.

One usual citation is Global Sex Differences in Test Score Variability (DOI: 10.1126/science.1162573). It uses standardized test scores. I quote findings below. Remarks inside parentheses are mine. "The third column in table S1, reports the estimated male/female variance ratios with standard errors in parentheses. In all but five countries (There are 41 countries) we can reject the hypothesis that the variance ratio…

> Another interpretation is that since variability difference is not universal (in 5 countries it is not statistically significant), variability difference is cultural. The later interpretation is argued in PNAS paper cited below.

How do they reach this conclusion? 36 for, 5 against at 95% significance level would expected given random variation, no?

Re: How Can There Still Be a Sex Difference, Even When There Is No Sex Difference?

#54
post #47

This article claims, > Last time we discovered that the brain of a woman is composed of two different types of cells. but if you actually read the last article, it has this example of mixed types of cells: > Surprisingly, there are some human females who also show a rather similar calico pattern ... for a very small number of women, if you were to look closely on a hot day, you would see a calico pattern appear on th…

The "very small number" applies to having visible calico skin pattern, not having two X chromosomes, a random one disabled in each cell.

Re: How Can There Still Be a Sex Difference, Even When There Is No Sex Difference?

#55
Female cells have just one X chromosome? That's totally new to me and sounds kind of strange.

Also socieconomic status shows higher variability under men than women. This is also a really heavy factor for intelligence and one of the reason why for instance ethnical minorities often perform worse in intelligence tests.

Re: How Can There Still Be a Sex Difference, Even When There Is No Sex Difference?

#56

I'm surprised to see this ranking so high on HN. Sex-based difference is the biggest taboo of our time. The current educational and political system is organized toward exclusively presenting the view that gender is a cultural construct and there are no differences between men and women other than plumbing. Men and women, on average, differ significantly on career choice, likes, dislikes, and motivation. And, it has…

> Men and women, on average, differ significantly The linked article explicitly does not take any stance on that. What the article points out is that males are more extreme in their traits, eg. exceptionally tall or exceptionally short, which in no way means that there are average differences. Even if the deviation is different, the mean may be the same. Not that I'm saying that those differences are or are not there…

You managed to misquote BADLY the article to support your point.

The article opens stating that there are TWO types of gender differences, one, like Height (that you quoted wrongly) is when the mean changes.

The other (like IQ) the distribution changes.

Then the article focus on theorizing why that second type happens, and don't discuss the first (wisely for the author, the same website used to have other authors on the subject, and they were all fired after public outcry after focusing on the first type of differences).

Re: How Can There Still Be a Sex Difference, Even When There Is No Sex Difference?

#57
post #15

Earlier quoted context omitted.

HN downvotes jokes, even jokes that are funny, and I prefer it that way.

Ironically also a great way to perpetuate the nerd stereotypes :)

It's a great way to keep our community unique and worth visiting. The world is full of vapid joke comments (anyone can make them).

Re: How Can There Still Be a Sex Difference, Even When There Is No Sex Difference?

#58

I'm surprised to see this ranking so high on HN. Sex-based difference is the biggest taboo of our time. The current educational and political system is organized toward exclusively presenting the view that gender is a cultural construct and there are no differences between men and women other than plumbing. Men and women, on average, differ significantly on career choice, likes, dislikes, and motivation. And, it has…

> Men and women, on average, differ significantly The linked article explicitly does not take any stance on that. What the article points out is that males are more extreme in their traits, eg. exceptionally tall or exceptionally short, which in no way means that there are average differences. Even if the deviation is different, the mean may be the same. Not that I'm saying that those differences are or are not there…

hence, if you sample either tail of the distribution you get on the average more men than women. and sampling one of the tails is exactly what selective schools/companies/sports clubs/etc tend to do.

Re: How Can There Still Be a Sex Difference, Even When There Is No Sex Difference?

#59

It's interesting to realize that if two groups have the same mean but different variability, the higher-variability group will have more outliers, on both the high end and the low end. The danger is a kind of genetic fatalism, assuming that what we should do is just to be determined by our genes and how our bodies work. For example, it's possible for a man to produce many children by impregnating lots of women concur…

I once found a "casual encounters" ad on craigslist, in which a woman sought men to attend a certain type of party, which type I do not remember. I looked it up at Urban Dictionary, the objective of that kind of party is to impregnate as many women as possible. I contemplated attending but then concluded that I want to know who my children are, and that they would want to know who their father is. Even under the best…

I suspect this is not unusual. I was asked to be a sperm donor at a party by a lesbian couple I'd never met before. They were completely serious, but the catch was no contact with the child.

The problem with arguments from reproductive psychology is that we know very little about reproductive psychology in history.

So modern ideas about female partner choice shaping genetics aren't necessarily a given. It's not unlikely there was plenty of rape, random sex with strangers because why not?, and all kinds of other non-vanilla behaviour.

Edit: And there's another issue - the implication that selecting for male variability is more successful as a species-wide reproductive strategy than selecting for high IQ.

That may be true, but it's a slightly strange place to end up in, because it implies that both ends of the bimodal curve are equally successful, and there's no selection advantage to being at the top of the curve. (If there were the bimodal would collapse to a standard Gaussian.)

Re: How Can There Still Be a Sex Difference, Even When There Is No Sex Difference?

#60

I'm surprised to see this ranking so high on HN. Sex-based difference is the biggest taboo of our time. The current educational and political system is organized toward exclusively presenting the view that gender is a cultural construct and there are no differences between men and women other than plumbing. Men and women, on average, differ significantly on career choice, likes, dislikes, and motivation. And, it has…

An excellent read is Why Gender Matters: What Parents and Teachers Need to Know about The Emerging Science of Sex Differences.

http://amzn.to/1NKVQ6d

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