Monday, January 18, 2010

Brief: More on measuring how aesthetic the zeitgeist has been over time

Returning to a previous attempt to measure how aesthetically minded people have been over time by using diversity in baby names, let's see if the frequency of relevant words in the newspaper of record agrees. I searched the NYT for "aesthetic" and "beautiful" back to 1852, and here are the results:

"Aesthetic" trends upward from the beginning through the early 1910's -- only some of which may have to do with Aestheticism in the arts -- and then declines until the mid-1940's, after which there is a gradual rise through the mid-1990's, and then an explosion from then until the present. "Beautiful" shows a pretty similar history, except for an initial decline during the 1850s (although the number of articles is much smaller in the beginning). It also has two apparent upward shocks: one in mid-1920's -- perhaps reflecting the 1925 world's fair in Paris that popularized Art Deco? -- and the other in the late 1970's. In the graph with moving averages, you can see how similar their trajectories have been. (They are also similar after 2000, but I left that stage out in order to better highlight the ups and downs in "aesthetic," which are hard to see against the recent explosion.)

They also agree well with the movements in the baby name diversity graph. Those data only go back to 1880, but there too we saw a rise from 1880 through the early 1910's, a slump through the mid-1940's, a moderate increase from then until the late 1980's, when it shot up even faster.

After the dizzying changes of industrialization during the latter half of the 19th C., and especially with the outbreak of WWI, many in the West became disillusioned with embracing global interconnectedness and cultural dynamism. Roughly from WWI through WWII, we became more inward-looking and focused on normalcy. We left that behind after winning WWII somewhat restored our faith in global relations and cultural change, and even more so during the most recent era of increased globalization.

There really does seem to be something about a cosmopolitan zeitgeist that makes people more concerned with aesthetic matters -- and clearly not just because the artists can now find mercantile patrons. It's not as though America in the Roaring Twenties wanted for wealthy donors. And a cynic would say that when the culture is becoming more cosmopolitan, status-seekers will try to one-up each other by showing off just how diverse their tastes are.

But I think it's more due to encountering new and exciting things from those other groups you're doing business with. And not only those across the world, but even from strange parts of your own country. Besides, it's not as if rich status-seekers are driving those trends in baby name diversity -- they're too small to count in data taken from social security cardholders. Ordinary people too get swept up in the age of aesthetics, as Virginia Postrel documents in The Substance of Style. To follow her most provocative example, Wal-Mart's website offers about five different streamlined styles of toilet brushes and as many different styles of toiletpaper holders. Wal-Mart shoppers are far below the elite in rank, and because hardly anyone will get the chance to see their brushed stainless steel toilet brush or abstract tulip-shaped toiletpaper holder, these items are unlikely to be only so much ammunition in the status war.

Wednesday, January 13, 2010

Just how permissive are the beliefs of non-heterosexuals?

Studies of gay and bisexual men show that they are more sexually permissive in their behavior, and likewise for bisexual women compared to straight or lesbian women. But sexual behavior is always constrained by the simple fact that it takes two. Why don't we look at their beliefs on sexually permissive behavior, which might give us a purer view of the differences between heterosexuals and non-heterosexuals.

(I collapse gay and bisexual males into a single non-heterosexual group, but preserve the three-part division among females, because that's what the findings on arousal argue for. Men are aroused either by male or female erotic images, but not by both; whereas some women truly are aroused by both.)

We will treat "sexual permissiveness" as a personality trait or preference that's too tough to measure precisely, but that we can investigate using La Griffe du Lion's method of thresholds. We imagine sexual permissiveness as a continuous trait -- some people score really low, others really high, and everything in between. At some point toward the high-end of this spectrum, we set a threshold and ask what percent of the various groups score above that threshold? We can then use this to figure out how far apart the average scores of the various groups are, assuming the trait to be normally distributed. Knowing that, we can also predict what ratio of one group to another we would expect at some extreme value of the trait -- far out into the right tail.

To identify a clearly high-end threshold for sexual permissiveness, consider what your beliefs are about two 14 to 16 year-olds having sex. The General Social Survey asks just such a question: is it always wrong, almost always wrong, sometimes wrong, or not wrong at all? As you look at higher values of sexual permissiveness, at some point you reach the value where the person is permissive enough to think that teenage sex is OK (maybe with provisos) rather than always wrong. Here is a picture to help see what I mean:

Along the spectrum of permissiveness, at the low end we find people who believe that oral sex is OK -- people whose value is to the left of that point are not even that permissive -- while farther to the right, we find people who are permissive enough to believe that teenage sex is OK. Farther to the right still, we find people with ever more permissive beliefs, perhaps going so far as to condone public unprotected sex. A group of people will have a distribution of values along this spectrum, and we'll assume it's normal for convenience and because most personality traits are made to be normal too. We also assume the various groups have the same variance.

By finding out what percent of some group lies to the right of our threshold point, we can work backward to determine what z-score this threshold represents for the group. Doing this for two groups, we can find the difference between the means of each. For example, if 16% of group A exceeds the threshold, while just 2.5% of group B exceeds the threshold, that implies that the threshold is +1 S.D. above A's mean and +2 S.D. above B's mean. That means that there is a difference of 2 - 1 = 1 S.D. between the two group's means, favoring A.

Furthermore, knowing how far apart the two groups are on average, we can extrapolate what the A-to-B ratio would be at an even further extreme value that we haven't even observed. Obviously there will be more A's than B's (if the two groups are the same size), but the question is by how much. These extreme value predictions are useful because we find extremes more fascinating than averages, and it may be harder to get honest answers out of people as we ask more and more extreme questions.

Now back to sexual permissiveness. The GSS allows two ways to figure out who is heterosexual or not. One is straightforward and asks what sex your sex partners have been over the last 5 years: only male, male and female, or only female. They also ask how many male (or female) partners you've had since age 18. If a male answers 0 partners, he's straight; if he answers 1 or more, he's not. You can do the same for females; bisexuals have to answer 1 or more partners for both questions. The sample sizes are a bit larger using the second method, but the results are very similar. So I'll show the graphs for both methods, but I'll only use the second one in applying the method of thresholds.

First, here are the graphs for male heterosexuals vs. non-heterosexuals, for the first and then second method:

Straight males are more likely to say teenage sex is always wrong, while gay males are more permissive -- although a bare majority of them still think it's always wrong. Next, the differences among females for the first and then second method:

Notice first that females overall are less permissive than males -- no surprise there. Lesbians are more permissive than straight females, but not nearly by the same gap as the one separating gay and straight males. However, there is a yawning chasm separating bisexual females not only from the other female groups but even from both male groups! This result about their beliefs is consistent with their sexual behavior, as surveys (including the GSS) routinely show that bisexual females lead over-sexed lives. They have a general "wild child" mindset, so it shouldn't be surprising that those who think teenage sex is always wrong are in the minority among bisexual women.

(I've looked at responses to this teenage sex question across all sorts of demographic groups, and aside from GSS respondents who are youngsters themselves, I haven't found a single group where the majority think it is OK, let alone one where one estimate puts them at over 60%. Very wild indeed.)

Comparing gay to straight males, we find a difference in means of 0.31 S.D. favoring gay males. Comparing lesbian to straight females, there is a 0.17 S.D. gap favoring lesbians. And comparing bisexual to straight females, there is a 0.68 S.D. gap favoring bisexuals. To make this more intuitive, let's pretend we were talking about height instead of sexual permissiveness. It's as if gay men were 0.92 inches "taller" than straight men on average; as if lesbians were 0.51 inches "taller" than straight women on average; and as if bisexual women were 2 inches "taller" than straight women on average. You might notice the gay-straight gap in the real world, probably not the lesbian-straight gap, but almost certainly you'd notice the bisexual-straight gap.

Now suppose we wanted to predict how much one group would predominate at an even more extreme value along the permissiveness spectrum. That might be holding the belief that it's OK to have unprotected sex in public -- or actually having done so. These extremes are harder to investigate directly because the events that would tip us off to people being there are incredibly rare, and asking people if they've ever had unprotected sex in public may not give us very reliable answers. So we turn to the method of thresholds and ask what ratio of non-heterosexuals to heterosexuals we predict to find at, say, the value of 3 S.D. above the heterosexual average.

Obviously this won't tell us what to expect in the real world since the straight and non-straight populations are very different in size. Still, we'll pretend they were the same size in order to highlight how different the various groups are. In a moment, I'll re-adjust these ratios to reflect the groups' real sizes in order to get better real-world predictions.

At the extreme value of 3 S.D. above the straight male mean, we expect a gay-to-straight ratio of 2.6 to 1. At the value of 3 S.D. above the straight female mean, we expect a lesbian-to-straight ratio of 1.7 to 1, and a bisexual-to-straight ratio of 7.6 to 1! Clearly the minds of heterosexuals and non-heterosexuals are not the same on average.

Correcting for the huge differences in population size between straights and non-straights, I've used the GSS to figure out what percent of the male and female population are gay, straight, or bisexual. For males, 96% are straight and 4% gay. For females, 96.4% are straight, 2% are lesbian, and 1.6% are bisexual. In the real world, then, we expect 9.2 straight males for every gay male at the extreme; 28.1 straight females for every lesbian; and 8 straight females for every bisexual female. The larger point remains, though: non-heterosexuals, especially bisexual women, are more permissive in the beliefs -- and so presumably in their actions -- than heterosexuals.

As an analogy, consider the fact that Ashkenazi Jewish people score much higher (about 1 S.D.) on IQ tests than other Europeans. Still, because Jews make up such a small fraction of the overall population (about 2%), it will still be the case that non-Jewish Europeans will outnumber Jews at extreme IQ levels. The first fact tells us that a representative person from the two groups will be pretty different, perhaps due to their ancestors facing different evolutionary selection pressures or due to having different hormone levels or whatever. The second fact tells us that we shouldn't let the first fact lead us to expect a majority of the unusual group at unusual levels, unless the two groups are similar in size.

GSS variables used: teensex, sex, sexsex5, nummen, numwomen

Monday, January 4, 2010

Brief: A season-of-birth effect in music preferences

The GSS asks people what their astrological sign is, allowing us to investigate season-of-birth effects. For instance, babies born in inclement weather may have different developmental shocks than summer-born babies do, and that could influence how they turn out as adults.

I looked for a season effect in personality traits, and although people are not uniformly the same across all birth months, there is either a very tiny pattern or larger but seemingly random differences. Nothing with a clear rising-and-falling pattern of great amplitude. For those things, season-of-birth at best plays a very small role in how you turn out.

But I did find a strong effect for whether you love classical music ("birth month" is the month that has the majority share of days belonging to a zodiac sign):

There are equally tall peaks among those born in February and those born roughly half a year later in July. There's a local trough among April births and a global trough among those born roughly half a year later in November. Maybe having weekly data would help us better resolve what the period of the cycle is, but it looks like half a year (5 months between peaks and 7 months between troughs). It can't be a particular type of weather that makes someone really dig classical music, since February is winter and July is summer. So perhaps the mechanism has to do with being exposed to extreme weather vs. mild weather as an infant (winter and summer vs. spring and autumn).

Also notice how wide the differences are: 10.9% for Scorpios vs. 21.2% for Cancers and 20.7% for Aquariuses -- nearly double. Imagine if season-of-birth doubled your chance of turning out some other interesting way, from 1 in 10 to 2 in 10 -- say, going to college or developing some disease. These are not small effects.

I stress that this is probably not mediated by intelligence or general personality traits like an openness to art or a taste for excitement, as these don't show this pronounced seasonal pattern. Nor do relevant behavioral variables like whether you went to a live performance of classical music or opera, whether you visited an art museum, whether you attended a dance performance, etc. Presumably those draw many other people in addition to those who are possessed by their love for classical music.

Music touches us in a strange way; it's not like literature that taps directly into our brain's language module, nor is it like visual art that taps directly into our visual center, face recognition module, and so on. It is very hard for music to tell a narrative as clearly as literature or a painting can. At best it can provoke a connected sequence of emotions. And unlike other music forms, classical relies heavily on harmony. Keeping track of the separate but interacting layers of melody is probably something our brain is not designed by natural selection to do; it's like following a conversation between four people who are talking at the same time. Perhaps it takes a certain degree of screwiness in the brain to really get that appeal of classical music, and that enduring extreme weather as a newborn helps that happen.

GSS variables used: zodiac, classicl

Brief: How does IQ predict vegetarian practices?

Our impression is that it's the smarter people who are more likely to practice vegetarianism to some degree. Go to a blue-collar picnic one weekend and a yuppy dinner party the next, and just ask which one had more vegetarian fare. At the former, we think of hamburgers and hot dogs, while we think of salad and risotto at the latter.

The GSS asks whether you refuse to eat meat for environmental reasons to varying degrees, or if you never abstain for such reasons. I've collapsed responses into refuse to eat meat to any degree (vegetarians) and never refuse to eat meat (omnivores). The pattern doesn't change if we look at the disaggregated data, but this makes the pattern easier to see. The GSS also gives a vocab test to roughly measure IQ. (I've collapsed those who got 0 to 2 words into one group just to keep sample sizes near 100 or greater.) Here is a graph that shows how likely a person is to be vegetarian to any degree depending on what their IQ is (red means veg):

This may shock us at first because vegetarianism almost strictly declines as IQ increases. Maybe we weren't considering representative samples of smarties -- maybe the more liberal or new age tribe among them goes vegetarian, while the conservative or traditional tribe goes for steak. I re-did the analysis looking only at liberals, and again only at conservatives, but the pattern holds up. Nor is there a strong relationship between vegetarianism and either income (meat is more expensive than corn, so that's worth looking at) or education level (this may affect your awareness of the treatment of animals, your exposure to philosophy classes, etc.). Strange as it may seem, there's something unique to smarts that makes you less likely to go veg.

There are the trend-bucking super-smarties, of course, but I'm inclined to believe this is a sort of counter-signaling -- adopting a lower-IQ practice to show that you can still do well even with such a handicap. The very smarts want some way to show that they have the analytical horsepower to have philosophical views on their diet, and at the same time look down their noses at the behavior of their immediate inferiors -- who serve such things as caviar, foie gras, and kobe beef at their parties -- so it's vegetarianism to the rescue!

GSS variables used: nomeat, wordsum, polviews, realinc, educ