« previous post | next post »

Bianca Nogrady, "Music preferences reveal your inner thoughts", ABC Science 7/23/2015:

There is a clear link between people's cognitive styles and the type and depth of emotion they prefer in music, say researchers.

Their work, published today in PLOS ONE, shows people who are more empathetic — have a greater ability to identify, predict and respond to the emotions of others — are drawn to more mellow, sad, poetic and sensual music, such as R&B, adult contemporary and soft rock.

However people with more analytical tendencies (called 'systemisers') go in the opposite direction, seeking punk, heavy metal, avant garde jazz and hard rock.

Makes sense, right? But here's what the underlying data looks like. Each red x represents the relationship between one individual's "empathy quotient" (on the horizontal axis) and his or her preference for "mellow" music (on the vertical axis):

Would you say that this represents a "clear link between people's cognitive styles and the type and depth of emotion they prefer in music"?

Actually, that's some fake data that I made up to match the strongest correlation (-0.14) found in Study 1 from David M. Greenberg , Simon Baron-Cohen, David J. Stillwell, Michal Kosinski, & Peter J. Rentfrow, "Musical Preferences are Linked to Cognitive Styles", PLoS ONE 7/22/2015. Here's their Table 1:

Note. Cell entries are correlations between the Empathy Quotient (EQ) and the MUSIC music-preference dimensions. S1 = Sample 1, S2 = Sample2, S3 = Sample 3, S4 = Sample 5. S1 and S2 provided preferences rating for mixed genre excerpts; S3 provided preferences ratings for only rock excepts; and S4 provided preference ratings for only jazz excerpts. Ns = 2,178 (S1), 891 (S2), 747 (S3), 320 (S4).

*p < .05;

**p < .01

The real dataset is apparently available from mypersonality.org, but I don't expect that it would look different in any relevant way.

A correlation of -0.14 means that one variable explains -0.14^2 = 1.96% of the variance in the other variable. Call it 2%. And that was highest correlation of the 40 relationships reported in Table 1.

Their second study combined "empathizing" and "systematizing" dimensions into one "brain type" dimension, and unpacked musical types into 25 "psychological attributes". Study 2 found relationships that were stronger than those in study 1:

To investigate the extent to which preferences for specific psychological attributes in music differ by brain type, we performed analyses of variance on each of the 25 psychological attributes (standardized) using brain type as the independent variable. Results revealed a significant effect of brain type on preferences for all but three of the psychological attributes (i.e., joyful, fun, and undanceable). Of those for which there was a significant effect, effect sizes ranged from F(2, 341) = 3.68, p < .05, partial eta squared = .02 (for amusing) to F(2, 341) = 8.11, p < .001, partial eta squared = .05 (for animated).

A "partial eta squared" of 0.05 — the best out of 25 tries — means that relations between the "brain type" variable and the musical attribute of animated accounted for (i.e. predicted) 5% of the variance in preferences for different pieces of music. All of the other relationships were weaker than this. 5 percent-of-variance-accounted-for is more than twice as much as the 2% that was the strongest relationship in study 1 — but it's still not a very strong predictor.

Although the effect sizes in both studies are small, they're in line with community standards in social psychology — thus F.D. Richard, C.F. Bond, and J.J. Stokes-Zoota ("One hundred years of social psychology quantitatively described", Review of General Psychology, 2003) present this distribution of correlations:

This article compiles results from a century of social psychological research, more than 25,000 studies of 8 million people. A large number of social psychological conclusions are listed alongside meta-analytic information about the magnitude and variability of the corresponding effects. References to 322 meta-analyses of social psychological phenomena are presented, as well as statistical effect-size summaries.

That doesn't mean that such studies are wrong or without value — marketers, like politicians, are happy to exploit effects that explain only a few percent of variance in customer behavior. Tiny improvements in click-through rates or voting behavior can mean a lot.

But the popular press is unable — or unwilling — to distinguish between "a tiny but statistically significant correlation" and "a clear link", often expressing the relationship using generic plurals. "People who are more empathetic […] are drawn to more mellow, sad, poetic and sensual music", according to that ABC Science News piece.

This is true even in the more intellectual strata of the mediasphere. Thus Olga Khazan, "The Soul of the Metallica Lover: What our music tastes say about our personalities", The Atlantic 7/29/2015:

Greenberg found that people who scored high on empathy tended to prefer music that was mellow (like soft rock and R&B), unpretentious (country and folk), and contemporary (Euro pop and electronica.) What they didn’t like, meanwhile, was “intense” music, which he classified as things like punk and heavy metal. People who scored high on systemizing, meanwhile, had just the opposite preferences—they kick back to Slayer and could do without Courtney Barnett.

Or Aimee Swartz, "Do you have a mellow brain or an intense one? Cognitive style linked to preference in pop music", Popular Science 7/22/2015:

Researchers found that people who scored high on empathy preferred what researchers categorized as “mellow” music—such as R&B, soft rock, and adult contemporary tunes—“unpretentious” music—such as country, bluegrass, and folk—and “contemporary” music—which included everything from acid jazz to Euro pop. They disliked “intense” music, such as punk, hard rock, and heavy metal.

In contrast, people who scored high on systemizing liked intense music, but disliked mellow and unpretentious musical styles.

As I've pointed out many times, this way of thinking about relationships among variables is as problematic as the Pirahã's reduction of numbers to the concepts "small size", "large size", and "collection".

For further exploration of statistical cognition among the hunter-gatherers of the media savanna, see here.

Permalink