Who has more general knowledge--men or women?

Richard Lynn and colleagues have done a series of studies (6) in multiple countries looking to see if there are sex differences in knowledge.  The thesis is that more intelligent people seek out and absorb more knowledge of all types.

The researchers focused on a wide variety of topics. Here are the sex differences in Cohen's d effect size statistics: over, say, 0.8 would be considered large. The black/white IQ gap is around 1.0, for example. A positive effect size indicates a male advantage; a negative Cohen's d means female advantage:

Sex difference--Cohen's d

General knowledge  .53
Games   .51
Jazz and blues  .46
Sports   .39
Finance  .35
Exploration   .33
General science   .32
Politics  .28
Geography  .27
History  .26
Medicine  -.24
Cookery   -.22
Classical music  -.19
Biology   -.11
Film   -.11
Art  -.08
Popular music  -.07
Fashion  -.05
Literature  .01

Men know more in 10 categories, while women take the lead in 8 areas. The female advantages tend to be small. When it is all summed up, men score one-half a deviation more than women. The samples are teenagers and young adults.  The male advantage would probably be bigger if the sample was older--knowledge accumulates with time.

The sex differences make sense. Men tend to know more about the more impersonal subjects: finance and science. Women tend to know a little more in softer "home topics" like medicine and cooking.

The results are consistent with the view that mean male intelligence is a few points higher than the female mean.

Who is more likely to be arrested--a white or black rapist?

Looking at the period 2005-2010, Steve Sailer shows that the black rate rape was 3.5 times higher than the white/Hispanic rate. His calculations are based on a very large national survey of Americans that asks about being a victim of crime and the characteristics of offenders.

If we do the same calculation based on FBI arrest data for the years 2008-2010 (2005-2007 are not available), the black rate is 3.1 times higher. What this tells us is that black rapists are less likely to get arrested than white/Hispanic rapists. The bias at the level of arrest is in favor of blacks and is in direct contradiction to the message that is drummed into us on a daily basis that the criminal justice system is deeply racist.

The Inductivist admits that culture matters

A pure naturist would claim that the culture of East Asians would not change after moving to America. Let's test this with one question from the General Social Survey that should differentiate Asians and whites: whether a not a child should learn to think for himself. Answers ranged from "most important for a child" (5) to least important (1).

Research has found that Westerners value independent-mindedness, while the East emphasizes fitting in. Here are the means for 1) American whites (n = 19,602), 2) Chinese (n = 102) and Japanese immigrants (n = 31), and 3) American-born Chinese ( n = 25) and Japanese (n = 26).

Mean score--valuing thinking for yourself

Native-born whites  4.00

American-born Japanese   4.00

American-born Chinese   3.72

Japanese immigrants   3.45

Chinese immigrants   3.18

Asians with individualist attitudes might choose to move to America, so the most relevant comparison is between immigrants and American-born Asians. The mean for Japanese immigrants is close to a half of a standard deviation less individualist than whites, but the American-borns do not differ from whites. 

Chinese immigrants are less individualist than Japanese immigrants, and while they do assimilate the same distance as the Japanese (roughly 1/2 sd), there remains a small difference between American-born Chinese and white Americans. 

So, the GSS data suggests that while genes might play a small role in the case of the Chinese, culture seems more important here. It might be the case that culture can influence attitudes quite a bit, but might have less impact on behavior (e.g., time studying) or abilities (e.g., IQ). 

UPDATE: I thought of a way that the Asian American embrace of independent-mindedness could be genetic: Asians might be predisposed to conform to whatever the mainstream culture is even if it's individualistic! 

By the logic of race deniers, sex is not real biologically either

A common argument made by race deniers is that since there is more variation within races than between them, race does not exist. Let's see how silly this seems if applied to something else.

Let's grab a random example of an obvious difference between men and women: height. The General Social Survey asked 2,632 people how tall they were in inches. The between-group variance is 8.04, while the within-group variance is 8.77. This means that women differ with each other in terms of height more than the sexes differ. Same for men. By the logic of the race deniers, sex is not a real thing.

Of course, these days many liberals believe that sex is not a biological reality, but they're daffier than Uncle Jaffey. 

What's the profile of a person who believes astrology is scientific? (Answer: the exact opposite of me)

Clearly, anyone who believes that astrology is scientific doesn't understand what science is, but how common is this belief, and what's the statistical profile of a believer?

The General Social Survey asked respondents the question with answers varying from "very scientific" to "not scientific" at all (sample size = 5,548). 36.6% of people said astrology was at least sort of scientific. That's a lot of dummies.

Here are the factors that predict belief (standardized OLS coefficients):

Predictors of thinking that astrology is scientific

Female   .09
Black   .13
Other race    .04
Age   -.07
IQ   -.17
Educational level   -.11
Church attendance   -.04
Political conservatism   -.04

All of the coefficients are statistically significant at the p < .01 level (or higher, two-tailed test).  So the profile looks like this: female, black (vs. white), other race (vs. white), young, unintelligent, uneducated, non-churchgoer, and liberal. The coefficients indicate the strength of the prediction: IQ is the best predictor of thinking astrology is not scientific.

Who has happier marriages--the religious or irreligious?

I haven't annoyed my irreligious friends in a while, and the only person who reads this blog that I don't want to be annoyed occasionally is me.

A common type of contemporary thinking goes like this: The more slowly, deliberately, and freely people decide to get married, the happier their marriage will be. Following this line, highly religious people should have the most miserable marriages because they marry younger. They might feel more pressure from family to get married and might want to avoid the temptations experienced all too often as singles.

The General Social Survey asked respondents how often they attend religious services and how happy their marriages are (if they are married).  The sample size is 11,543:

The pattern is clear:  satisfaction with one's marriage rises with church attendance, especially among more frequent churchgoers.

In recent years, I've been shifting away some from the conservative sociologist's view that traditional institutions (e.g., church, marriage) improve people's lives toward the naturist view that people with certain genetically-influenced traits (i.e., agreeableness, conscientiousness) select themselves into traditional institutions. There could be some truth to both views.

Marriage and religion are universal practices, and as NN Taleb instructs us, institutions that have been around forever are probably doing something for us whether we understand it fully or not.

The BIGGEST sex differences

A study by John Archer reviewed meta-analyses on psychological sex differences, so we're talking about hundreds of studies. I will highlight the largest differences; those with means that are at least eight-tenths of a standard deviation apart. For the non-stats people among us, that is a very big gap.

Largest sexually dimorphic psychological traits (difference in sd units)

Homicide   2.54
Rape   2.32
Mate choice--Age difference   2.00
Violent computer-game use   1.41
Occupational interests   1.39
Systemizing   1.21
Pain tolerance  1.17
Fear in real-world situations   -1.16
Violent crime   1.11
Engineering interests   1.11
Partner homicide   1.06
People-things distinction   -.93
Empathy   -.91
Weapons use  .88
Sexual v. emotional jealousy  .87
Revenge   .83

Among the traits that Archer included, there is no bigger difference between the sexes than violence. Men are the violent sex and love it much more than women (i.e., violent video game use).

Male superiority in visuospatial ability is talked about a lot, and there is a difference, but it is not large enough to make the list. Interest is where the big gap exists. Men are much more likely to have an interest in engineering, making systems, and working with things over people.

While I've admired my wife's ability to suffer the pains of childbirth repeatedly, experimental research indicates that men can tolerate pain much better than women. Women are much more fearful of being harmed in real-world situations. This might figure into male willingness to get his ass kicked in a fight.

Women are the empathetic sex. They are much less likely to desire revenge. They get jealous about their man having romantic attachments, while men are much more concerned about sexual betrayal. Women desire older, resource-possessing men, while men desire younger women who have lots of reproductive potential.

These sex differences are what evolutionary theory would predict: men compete with each other, sometimes violently and vengefully, for access to mates.

There must have been benefits for women to be more sensitive to the feelings of others--effective childcare comes to mind--and men must have benefitted from a greater orientation to the analysis of systems. Strategic thinking for hunting and war?


UPDATE: Archer neglects to include perhaps the largest psychological sex difference: males are overwhelming attracted to females, while females are overwhelmingly attracted to males. The exceptions are noise. And the evolutionary reason is obvious.

Is the black-white IQ gap caused by income inequality?

Some liberal researchers contend that the black/white IQ gap is due to income inequality. If that is true, then changes in the IQ gap over the past few decades should parallel changes in income disparities.

Here are graphs for males and females generated from General Social Survey data (sample size = 25,589).  (For many analyses, it is appropriate to use median income, but we are interested in inequality so the mean makes more sense).

Mean individual income (constant $)--males

Mean IQ--males

For men, the black-white gap in income grew over the past five decades. The gap in constant dollars is $12,300 in the 1970s and $18,400 in the 2010s. This kind of widening should lead to a larger IQ gap, but the IQ difference shrunk from 10.6  to 8.2 points over the same period.


Mean individual income (constant $)--females

Mean IQ--females

We see the same widening income gap for women from $1,300 in the 1970s to $5,900 in the 2010s.  Over the same period, the IQ gap dropped from 11.6 to 8.6 points.

Once again, the trends contradict the liberal prediction.

Now, you might respond that GSS data do indicate a narrowing of the racial IQ gap over the past five decades, and indeed they do. We don't know for sure why that is--it might be due to the horrible black high schools in the South getting better in the last few decades (perhaps vocabularies can be improved a little with decent schools)--but the point of this post is that it does not look like the difference in black and white IQs is due to the fact that whites make more money.

UPDATE: Sean Last posted this Pew graph which shows a widening in the black-white income gap:

An analogy that might offend

I'm surprised I've never run across this analogy for homosexuality that now occurs to me.  Imagine a group of people who are, what we could call, alternative eaters.

For whatever reason, these folks prefer to consume food either through their nostrils or their anuses.

And imagine that sensitive individuals didn't want to exclude any of variety of preference. It's not fair that the anus eaters get all the attention, so we develop an inclusive acronym. We call anus eaters A's, and those who prefer nostril eating N's. If they enjoy both methods, we'll call them AN's.

Some like both mouth eating and anus eating, so we call them MA's. Those who like mouth eating and nostril eating, we'll call MN's. A few enjoy all three methods, so we call them Tri's or T. Those who are trying to figure out which methods they prefer, we will call I's for investigating. For all others, we'll indicate a plus sign. That leaves us with the acronym of ANANMAMNTI+.

And don't get me started on the people who like alternative excretion.

Why I write about human biodiversity

We HBD-ers are in an unfair situation.  I'll explain it with an analogy.  My wife is a beautiful woman, but let's imagine she's ugly as sin. And let's add she would make a good Jerry Springer guest.

Now, imagine we're at a dinner party, and all the attractive people there make her feel inadequate. So she gets upset with me and starts yelling about how I am never willing to pay for high-quality cosmetics, gym memberships, or expensive cosmetic surgery. I'm very embarrassed that she is making a scene in public, but she has just slandered me, so I proceed to explain to everyone that I have paid for attractive clothing, cosmetics, gym memberships, and plastic surgery, but the simple truth is that my wife is ugly, and nothing will change that. And how does the crowd react? Do they chide her for making false, nasty accusations in front of everyone? No, the crowd turns on me and thinks I'm an asshole for saying out loud that my wife is ugly.

People who report the facts about human diversity get the same kind of treatment. Liberals denounce whites publicly all the time for keeping minorities poor and dysfunctional. When we explain that the causes of minority problems are internal--for example, that they are due to lower intelligence--and that they don't have much to do with us, the crowd doesn't see the accusers as really nasty and unfair; instead, they turn on us as being insulting and abusive. And for the Left, being rude reveals that one is filled with hate.

I know that many HBD advocates preach truth first, middle, and last. I have another view.  If my wife were ugly, I wouldn't say it even though it's true. I would be diplomatic. I would only speak of it if I really needed to--perhaps if she were packing her bags to devote her life to becoming a Hollywood starlet. You speak unpleasant truths if you need to defend yourself, or it's the only way to help; if it's really necessary. And you don't go on about it.

The only reason I go on about HBD issues all the time is because the Left is destroying our society with its lying, irrational race obsession. I'm trying to help. I'll shut up when they do.