September 30, 2006

Gender myths: letting science mislead

Last night's edition of ABC's 20/20 included several segments ( "The Truth Behind Women's Brains" and "Gender Myths: Let Science Decide") that show the growing influence of pseudo-scientific neuro-biologism in American public discourse about sex roles. The "Truth Behind Women's Brains" segment featured an interview with Louann Brizendine, which presented pretty much all of the material from her book that's been discussed in earlier Language Log posts. I won't repeat myself here.

But some striking fragments of misinterpreted science also made it into the "Let Science Decide" segment, for example this one:

"The male brain … actually has a harder time processing the female voice versus the male voice, which is a possible explanation to why we don't listen when our wives call us," Dr. Billy Goldberg said on "20/20."

Goldberg and Mark Leyner are co-authors of "Why Do Men Fall Asleep After Sex?"

They said it was true that men listened less because of biology.

Right. I believe that this is a reference to some research that got a great deal of (spectacularly misleading) media exposure about a year ago: Dilraj S. Sokhi, Michael D. Hunter, Iain D. Wilkinson and Peter W.R. Woodruff, "Male and female voices activate distinct regions in the male brain", NeuroImage 27(3) 572-578, 2005.

I blogged about this research at mind-numbing length in an earlier post ("Rorschach science", 8/12/2005). Here's the executive summary:

  1. They recorded some male and female voices.
  2. They speeded up the male voices until the pitch was like the female voices, and slowed down the female voices until the pitch was like the male voices. As a side effect, this also made the male recordings about 1.5 times faster (and shorter), and the female voices a comparable fraction slower (and longer).
  3. This gives four categories of sounds: original male, original female, hacked male, hacked female.
  4. They played the results to subjects in an fMRI brain-imaging experiment.
  5. The subject were 12 males. (And zero females).

They then determined which brain regions showed various boolean combinations of statistically-significant effects, e.g.

  1. (original female > original male) AND (hacked female > hacked male). (which they called "female versus male")
  2. (original male > original female) AND (hacked male > hacked female). ( which they called "male versus female")

The purpose of hacking the voices was to eliminate the obvious possibility that the subjects' brains were just responding to the differences in pitch. The researchers' goal was to find where and how the men's brains were responding to the identification of femaleness or maleness in the voices -- though this is curiously at variance with their assertion that the pitch-adjusted voices were perceived as "gender-neutral". (I suspect that they were probably perceived as species-neutral as well...)

Anyhow, I pointed out that there are lots of alternative ways to describe the effects as they defined them -- e.g. lower-pitch-and-shorter-phrases-vs.-higher-pitch-and-longer-phrases rather than male-vs-female. More to the point, though, the researchers only used men as subjects -- for all they (and we) know, female subjects would have responded in exactly the same way.

However, my objection was not to the research itself. I would have preferred to see more appropriate methods of signal processing applied to the voices, and it seems important to see a comparison with female subjects, but those are issues that could be addressed in follow-up experiments.

What I objected to was the media reaction. Here's how I quoted it, back in August of 2005:

Some headlines: "Er, you what, luv?" -- "Man Leaves Wife, Realizes Six Hours Later" -- "Female Voices are Easier to Hear" -- "What We Have is Failure to Communicate" -- "Men do Have Trouble Hearing Women" -- "Why Imaginary Voices are Male" -- "It's official! Listening to women pays off" -- "Men do have trouble hearing women, scientists find".

The blogospheric reactions are just as creative: "I can't hear you,'re just too difficult to listen to" -- "What to tell your wife when you didn't hear her" -- "Men who are accused of never listening by women now have an excuse -- women's voices are more difficult for men to listen to than other men's, a report said" -- "I've been waiting for this for a long time. I'm often accused of 'selective hearing' in which certain statements just disappear from my consciousness - often statements made by Mrs. HolyCoast. It usually occurs when I'm multi-tasking, such as watching TV or blogging while listening to my better half..." -- "Science explains patriarchal monotheism!" ...

My conclusion?

[A]s for the rorschach-blot reactions in the popular press and the blogs, about how this explains why men have a hard time paying attention to women, or why women's speech is more valuable, or why men and women often fail to communicate... Well, what's responsible for these responses is not the STG or the precuneus, it's the limbic system. When people have strong and complex feelings about a topic, research results become a screen for them to project their preconceptions onto.

And now the writers of pop neuro-psychology books like "Why do men fall asleep after sex?" take it as scientifically established that "men listen less because of biology", and that "The male brain … actually has a harder time processing the female voice versus the male voice".

I keep reminding myself that this is all still a step up from the infamous BBC cow-dialects story, in that at least there is an actual published study behind it, even if the underlying research lends no credence at all to the interpretations it's being given. But then again, maybe it's worse. The only social consequence of belief in cow dialects is to help spread the appellation d'origine controllée concept to cheese, and who can really object that?

In any case, for ABC 20/20 to call this "letting science decide" is splendidly ironic.

Posted by Mark Liberman at September 30, 2006 07:25 PM