Tag Archives: international comparisons

The Truth About Gender and Math

New data about the science aptitude of boys and girls around the world inspires me to re-post this discussion from 2010.
Math ability, in some societies, is gendered.  That is, many people believe that boys and men are better at math than girls and women and, further, that this difference is biological (hormonal, neurological, or somehow encoded on the Y chromosome).

But actual data about gender differences in math ability tell a very different story.  Natalie Angier and Kenneth Chang reviewed these differences in the New York Times.  They report the following (based on the US unless otherwise noted):

•  There is no difference in math aptitude before age 7.  Starting in adolescence, some differences appear (boys score approximately 30-35 points higher than girls on the math portion of the SAT).  But, scores on different subcategories of math vary tremendously (often with girls outperforming boys consistently).

•  When boys do better, they are usually also doing worse.   Boys are also more likely than girls to get nearly all the answers wrong.  So they overpopulate both tails of the bell curve; boys are both better, and worse, than girls at math.

•  That means that how we test for math ability is a political choice.  If you report who is best at math, the answer is boys.  If you report average math ability, it’s about the same.

•  How you decide to test math ability is also political.  Even though boys outperform girls on the SAT, it turns out those scores do not predict math performance in classes.  Girls frequently outperform boys in the classroom.

•  And, since girls often outperform boys in a practical setting, math aptitude (even measured at the levels of outstanding instead of average performance) doesn’t explain sex disparities in science careers (most of which, incidentally, only require you to be pretty good at math, as opposed to wildly genius at it).   In any case, scoring high in math is only loosely related to who opts for a scientific career, especially for girls. Many high scoring girls don’t go into science, and many poor scoring boys do.

Now, let’s look at some international comparisons:

•  Boys do better in only about ½ of the OECD nations. For nearly all the other countries, there were no significant sex differences. In Iceland, girls outshine boys significantly.

•  In Japan, though girls perform less well than the boys, they generally outperform U.S. boys considerably.  So finding that boys outperform girls within a country does not mean that boys outperform girls across all countries.

•  Still, even in Iceland, girls overwhelmingly express more negative attitudes towards math.

So what’s the real story here?  Well, one study found that the gender gap in math ability and the level of gender inequality in a society were highly correlated. That is, “…the gender gap in math, although it historically favors boys, disappears in more gender-equal societies.”

Part of the problem, then, is simply that  girls and boys internalize the idea that they will be bad and good at math respectively because of crap like the “Math class is tough!” Barbie (sold and then retracted in 1992):

However, girls’ insecurity regarding their own math ability isn’t just because they internalize cultural norm, their elementary school teachers, who are over 90% female, sometimes do to and they teach math anxiety by example.  A recent study has shown that, when they do, girl students do worse at math.  From the abstract (this is pretty amazing):

There was no relation between a teacher’s [level of] math anxiety and her students’ math achievement at the beginning of the school year.  By the school year’s end, however, the more anxious teachers were about math, the more likely girls (but not boys) were to endorse the commonly held stereotype that “boys are good at math, and girls are good at reading” and the lower these girls’ math achievement.  Indeed, by the end of the school year, girls who endorsed this stereotype had significantly worse math achievement than girls who did not and than boys overall.

So, with only the possible exception of genius-level math talent, men and women likely have equal potential to be good (or bad) at math.  But, in societies in which women are told that they shouldn’t or can’t do math, they don’t.  And, as Fatistician said, “math is a skill.”  People who think practicing it is pointless won’t practice it.  And those who don’t practice, won’t be any good at it… Y chromosome or no.

Lisa Wade is a professor of sociology at Occidental College and the author of Gender: Ideas, Interactions, Institutions, with Myra Marx Ferree. You can follow her on Twitter and Facebook.

Family, Race, Religion: The U.S. is Becoming More Diverse

Cross-posted at Racialicious and Family Inequality.

Trying to summarize a few historical trends for the last half century, I thought of framing them in terms of diversity.

Diversity is often an unsatisfying concept, used to describe hierarchical inequality as mere difference. But inequality is a form of diversity — a kind of difference. And further, not all social diversity is inequality. When people belong to categories and the categories are not ranked hierarchically (or you’re not interested in the ranking for whatever reason), the concept of diversity is useful.

There are various ways of constructing a diversity index, but I use the one sometimes called the Blau index, which is easy to calculate and has a nice interpretation: the probability that two randomly selected individuals are from different groups.

Example: Religion

Take religion. According to the 2001 census of India, this was the religious breakdown of the population:


Diversity is calculated by summing the squares of the proportions in each category, and subtracting the sum from 1. So in India in 2001, if you picked two people at random, you had a 1/3 chance of getting people with different religions (as measured by the census).

Is .33 a lot of religious diversity? Not really, it turns out. I was surprised to read on the cover of this book by a Harvard professor that the United States is “the world’s most religiously diverse nation.” When I flipped through the book, though, I was disappointed to see it doesn’t actually talk much about other countries, and does not seem to offer the systematic comparison necessary to make such a claim.

With our diversity index, it’s not hard to compare religious diversity across 52 countries using data from World Values Survey, with this result:


The U.S. is quite diverse — .66 — but a number of countries rank higher.


Increasing U.S. Diversity

Anyway, back to describing the last half century in the U.S. On four important measures I’ve got easy-to-identify increasing diversity:





The last one is a little tricky. It’s common to report that the median age at marriage has increased since the 1950s (having fallen before the 1950s). But I realized it’s not just the average increasing, but the dispersion: More people marrying at different ages. So the experience of marriage is not just shifting rightward on the age distribution, but spreading out. Here’s another view of the same data:


I calculated these using the Panel Study of Income Dynamics from 1968 (for those married in the years 1950-1968) and comparing it with the 2011 American Community Survey for those married in the previous year. There might be a better way, of course.

I have complained before that using the 1950s or thereabouts as a benchmark is misleading because it was an unusual period, marked by high conformity, especially with regard to family matters. But it is still the case that since then diversity on a number of important measures has increased. Over the period of several generations, in important ways the people we randomly encounter are more likely to be different from ourselves (and each other).

Philip N. Cohen is a professor of sociology at the University of Maryland, College Park, and writes the blog Family Inequality. You can follow him on Twitter or Facebook.

Assault Deaths Within the United States

Cross-posted at Kieran Healy’s blog.

The chart in “America is a Violent Country” has been getting a lot of circulation. Time to follow up with some more data. As several commentators at CT noted, the death rate from assault in the U.S. is not uniform within the country. Unfortunately, state-level and county-level mortality data are not easily available for the time period covered by the previous post — though they do exist, going back to the 1940s. What I have to hand is a decade’s worth of US mortality data courtesy of CDC WONDERcovering 1999 to 2009. I extracted the assault deaths according to the same criteria the OECD uses (for the time period in question, ICD-10 codes X85-Y09 and Y87.1). The estimates are adjusted to the 2000 U.S. population, which isn’t identical to the standard OECD adjustment. But the basic comparability should be OK, for our purposes.

First, it’s well-known that there are strong regional differences in the assault death rate in the U.S. by state and region. Here’s what the patterns look like by state from 1999 to 2009 (click for a larger PNG or PDF):

This figure excludes the District of Columbia, which has a much higher death rate but is also a city. Also missing are a few states with small populations and low absolute numbers of assault deaths — Wyoming, North Dakota, Vermont — such that the CDC can’t generate reliable age-adjusted estimates for them. If you want a “small-multiple” view with each state shown separately from high to low, here you go.

The legend for the figure above arranges the states from high to low, reading top to bottom and left to right. Although it’s clear that geographical region isn’t everything, those tendencies are immediately apparent. Let’s look at them using the official census regions (click for a larger PNG or PDF):

As is well known, the South is more violent than the rest of the country, by some distance. Given the earlier post, the natural thing to do is to put these regional trends into the cross-national comparison and see — for the decade we have, anyway — how these large U.S. regions would fare if they were OECD countries. Again, bear in mind that the age-adjustment is not quite comparable (click for a larger PNG or PDF):

Despite their large differences, all of the U.S. regions have higher average rates of death from assault than any of the 24 OECD countries we looked at previously. The placid Northeast comes relatively close to the upper end of the most violent countries in our OECD group.

Finally, there’s the question of racial and ethic incidence of these deaths within the United States. Here are the decade’s trends broken out by the race of the victim, rather than by state or region (click for a larger PNG or PDF):

The story here is depressing. Blacks die from assault at more than three times the U.S. average, and between ten and twenty times OECD rates. In the 2000s the average rate of death from assault in the U.S. was about 5.7 per 100,000 but for whites it was 3.6 and for blacks it was over 20. Even 3.6 per 100,000 is still well above the OECD-24 average, which – if we exclude the U.S. – was about 1.1 deaths per 100,000 during the 2000s, with a maximum value of 2.9. An average value of 20 is just astronomical. And this is after a long period of decline in the death rate from assault.


Kieran Healy is a professor of sociology in the Kenan Institute for Ethics at Duke University.  His research is primary concerned with the moral order of a market society. You can follow him on twitter and at his blog.

America Is a Violent Country

Cross-posted at Kieran Healy’s blog.

The terrible events in Connecticut prompted me to update an old post about comparative death rates from assault across different societies. The following figures are from the OECD for deaths due to assault per 100,000 population from 1960 to the present.

As before, the most striking features of the data are (1) how much more violent the U.S. is than other OECD countries (except possibly Estonia and Mexico, not shown here), and (2) the degree of change — and recently, decline — there has been in the U.S. time series considered by itself. Note that “assault” as a cause of death does not distinguish the mechanism of death (gunshot, stabbing, etc). If anyone knows of a similar time series for gun-related deaths only, let me know.

(Click for a larger PNG or PDF.)

Here are the individual time series:

(Click for a larger PNG or PDF.)


Kieran Healy is a professor of sociology in the Kenan Institute for Ethics at Duke University.  His research is primary concerned with the moral order of a market society. You can follow him on twitter and at his blog.

Who Would the World Elect?

A BBC poll of almost 22,000 people in 21 countries found that, on average, they preferred Obama to Romney more than five to one.  Only one country, Pakistan, would elect Romney.

Results ranked by support for Obama:

Results ranked by support for Romney:

What does it mean that this is such a close race here?

Via The Grumpy Sociologist.

Lisa Wade is a professor of sociology at Occidental College and the author of Gender: Ideas, Interactions, Institutions, with Myra Marx Ferree. You can follow her on Twitter and Facebook.

Reducing Poverty: Where There’s a Will…

Cross-posted at Montclair SocioBlog.

The poverty rate in the US in the mid-2000s was about 17%.  In Sweden, the poverty rate was 5.3%; in Germany, 11%.   That was the rate after adding in government transfers.  In Germany, the poverty rate before those transfers was 33.6%, ten points higher than that in the US.  Sweden’s pre-transfer poverty rate was about the same as ours.

Jared Bernstein has this chart showing pre-transfer and post-transfer rates for the OECD countries (click to enlarge):

Three  points:

1.  Governments have the power to reduce poverty, and reduce it a lot.  European governments do far more towards this goal than does the US government.

2.  It’s unlikely that America’s poor people are twice as lazy or unskilled or dissolute as their European counterparts.  Individual factors may explain differences between individuals, but these explanations have little relevance for the problem of overall poverty.  The focus on individual qualities also has little use as a basis for policy.  European countries have fewer people living in poverty, but not because those countries exhort the poor to lead more virtuous lives and punish them for their improvident ways.  European countries have lower poverty rates because the governments provide money and services to those who need them.

3.  The amount of welfare governments provide does not appear to have a dampening effect on the overall economy.

Vacation in International Perspective

Cross-posted at Montclair SocioBlog.

As I speculated years ago (here and here), it may be hard for Americans to imagine a world where the law guarantees them at least 20 paid vacation days per year.  But such a world exists.  It’s called Europe.*

Americans are the lucky ones.  As Mitt Romney has warned us “European-style benefits” would   “poison the very spirit of America.”  Niall Ferguson, who weighs in frequently on history and economics, contrasts America’s “Protestant work ethic” with what you find in Europe – an “atheist sloth ethic.”

The graph is a bit misleading. It shows only what the law requires of employers.  Americans do get vacations.  But here in America, how much vacation you get, or whether you get any at all, and whether it’s paid – that all depends on what you can negotiate with your employer.

Since American vacations depend on what the boss will grant, some people get more paid vacation, some get less, and some get none.  So it might be useful to ask which sectors of our economy are beehives of the work ethic and which are sloughs of sloth.  (Ferguson’s employer, for example, Harvard University, probably gives him three months off in the summer, plus a week or two or more in the winter between semesters, plus spring break, and maybe a few other days.  I wonder how he would react if Harvard did away with these sloth-inducing policies.)

The Wall Street Journal recently (here) published a graph of BLS data on access to paid vacations; they break it up by industry near the bottom.

Those people who are cleaning your hotel room and serving your meals while you’re on vacation — only about one in four can get any paid vacation days.  And at the other end, which economic sector is most indulgent of sloth among its workforce?  Wall Street.  Four out of five there get paid vacation.

How much paid vacation do we get?  That depends on sector, but it also depends on length of service.  As the Journal says,

Europeans also get more time off: usually a bare minimum of four weeks off a year. Most Americans have to stay in a job for 20 years to get that much, according to BLS data.


* The graph is from five years ago, but I doubt things have changed much. The US still has no federal or state laws requiring any paid vacation days.

Declining Faith in Hard Work and Capitalism

Cross-posted at Reports from the Economic Front.

The Pew Research Center recently published a report titled “Pervasive Gloom About the World Economy.” The following two charts come from Chapter 4 which is called “The Causalities: Faith in Hard Work and Capitalism.”

The first suggests that the belief that hard work pays off remains strong in only a few countries: Pakistan (81%), the U.S. (77%), Tunisia (73%), Brazil (69%), India (67%) and Mexico (65%). The low scores in China, Germany, and Japan are worth noting. This is not to say that people everywhere are not working hard, just that many no longer believe there is a strong connection between their effort and outcome.

The second chart highlights the fact that growing numbers of people are losing faith in free market capitalism.  Despite mainstream claims that “there is no alternative,” a high percentage of people in many countries do not believe that the free market system makes people better off.

GlobeScan polled more than 12,000 adults across 23 countries about their attitudes towards economic inequality and, as the chart below reveals, the results were remarkably similar to those highlighted above.  In fact, as GlobeScan noted, “In 12 countries over 50% of people said they did not believe that the rich deserved their wealth.

It certainly seems that large numbers of people in many different countries are open to new ways of organizing economic activity.

Martin Hart-Landsberg is a professor of economics at Lewis and Clark College. You can follow him at Reports from the Economic Front.