April 04, 2007

The Female Brain is out in Britain

Louann Brizendine's The Female Brain came out in the UK on April 2, in paperback. This time, the cover represents a woman's brain as a purse jam-packed with cell phone, mirror, cosmetics, photos and so on, in place of the (oddly 1970-ish) image of a brain-shaped tangled curly phone cord that adorned the dust jacket of the U.S. hardcover edition.

I haven't seen a copy of the U.K. paperback, and so I don't know to what extent the various sexual urban legends in the U.S. edition have been modified or backed up with relevant scientific sources. But based on the new quotations in Deirdre Ferdinand's April 1 article in the Sunday Times, "Two sexes divided by a single brain", it looks like Dr. Brizendine is continuing to show that she deserved to win the coveted Goropius Becanus Award for 2006.

In particular, the quantitative assertions about alleged female talkativeness apparently still stand, although the old numbers may be given a new rationale. Pending a look at the new version of the book, there have been four perspectives from Dr. Brizendine on this point available in print:

  1. In the U.S. edition of her book: "A woman uses about 20,000 words per day while a man uses about 7,000"
  2. Quoted in the Guardian (11/27/2006): "I understand Mark Liberman's point and I am grateful to him. He felt I was passing on data that was not nailed down, and thus perpetuating a myth, so it will be taken out in future editions."
  3. Quoted in the New York Times (12/10/2006): "The real phraseology of that should have been that a woman has many more communication events a day — gestures, words, raising of your eyebrows."
  4. In the Sunday Times (4/1/2007): "That’s merely in a social setting. In a boardroom women often say very little."

Not being a member of any boards of directors, I can't evaluate the boardroom point from personal experience -- and I rather doubt that there are any systematic recordings and transcripts available to test the question empirically. (Dr. Brizendine's home page doesn't list any board memberships either, though perhaps they were simply left out. It does tell us, though, that The Male Brain is due out in 2008...)

However, there is quite a bit of evidence from different sorts of "social setting" -- including a study, recently submitted for publication, that gives daily word counts for several hundred subjects in two countries who wore recording devices for several days each -- and the results are consistent: the average differences in talkativeness between males and females are small, relative to the within-sex variation, and show the average male as more talkative than the average female at least as often as the other way around.

Here are some further details on the history of Dr. Brizendine's statements on this point:

From the phone interview with Stephen Moss from the Guardian:

When I reach Brizendine, just as she is crossing the Golden Gate bridge, she tells me that she has accepted the criticism of the numbers quoted in the book - on both volume of words and rate of speech - and will be deleting them from future editions. Nor will they appear in the UK edition, to be published by Bantam in April. "I understand Mark Liberman's point and I am grateful to him," she says. "He felt I was passing on data that was not nailed down, and thus perpetuating a myth, so it will be taken out in future editions." She admits language is not her specialism, and she had been reliant on the advice of others.

From an interview with Deborah Solomon in the NYT:

Q: Your book cites a study claiming that women use about 20,000 words a day, while men use about 7,000.
A: The real phraseology of that should have been that a woman has many more communication events a day — gestures, words, raising of your eyebrows.

And most recently, quoted by Deirdre Ferdinand in the Sunday Times:

Brizendine, who studied neurobiology at Berkeley, medicine at Yale and psychiatry at Harvard, has an impeccable pedigree to help her defend some of her most controversial claims.

One of them, for instance, which suggests that women use 20,000 words a day compared with 7,000 for men, has been hotly disputed. As ever, context and interpretation of data are key. “That’s merely in a social setting,” she counters. “In a boardroom women often say very little.”

If you happen to be in Great Britain and see a copy of the book, please let me know what it says on this topic (and the related topic of speaking rate). For comparison, the relevant parts of the U.S. edition were discussed in these previous Language Log posts:

"Neuroscience in the service of sexual stereotypes" (8/6/2006)
"Sex-linked lexical budgets" (8/6/2006)
"Sex and speaking rate" (8/7/2006)
"Yet another sex-n-wordcount sighting" (8/14/2006)
"The main job of the girl brain" (9/2/2006)
"The laconic rapist in the womb" (9/4/2006)
"Open-access sex stereotypes" (9/10/2006)
"Gabby guys: the effect size" (9/25/2006)
" Word counts" (11/28/2006)
"Sex differences in "communication events" per day?" (12/11/2006)

Judging from the Sunday Times quotes, some of the other quantitative inventions in The Female Brain are also intact:

"It’s true that the female brain shrinks by about 8% during pregnancy. That’s the bad news, but the good news is that it recovers about six to 12 months afterwards to create large maternal circuits."

Last year, when I looked up Dr. Brizendine's reference for this assertion ("The spread of bogus numbers in the meme pool", 10/16/2006), I found that the 8% number is not entirely made up, like the words-per-day numbers -- but it was based on one small study, whose results were substantially below the cited value:

There were two women in the study, number 6 and 8, who were measured both before pregnancy and at term. Over that period, their brains shrank 4.06% and 6.6% respectively, for an average of 5.3%. There were eight women in the normal group whose brains were measured at term and 24 week (i.e. six months) after delivery. Their brains increased in size during that time by 4.0%, 3.0%, 5.5%, 3.2%, 4.8%, 5.6% and 5.1% respectively, for an average of 4.3%, with a 95-percent confidence interval of 3.4% to 5.2%.

(And there's no scientific support for the view that circuits of any particular kind are being either destroyed or created. The study simply measured overall brain volume, without distinguishing among gray matter, white matter, blood vessels or whatever else, and without providing any evidence about the relationship of the changes in overall size to any changes in number of neurons, number or type or strength of synaptic connections, or any other functionally-relevant parameters. It seems unlikely that such rapid changes in overall size could be due to the death and birth of neuronal cell bodies, or to atrophy and re-creation of a large fraction of the dendritic arborization.)

But that exaggeration is a tiny one compared to those referenced in this paragraph from Ferdinand's review:

Testosterone in the male foetus, for instance, will shrink the brain’s communication centre, reduce the hearing cortex and make the part of the brain that processes sex twice as large as that of the female. Thoughts about sex enter a woman’s brain perhaps once a day, but in a man every time he sees an attractive woman.

For discussion, see these earlier posts:

"The laconic rapist in the womb" (9/4/2006)
""Every 52 seconds": wrong by 23,736 percent?" (10/13/2006)

A catalogue of other relevant LL posts can be found here.

And for a general evaluation of the book's endocrinology, pharmacology, and neurobiology, take a look at the review by Rebecca M. Young and Evan Balaban from Nature, October 2006: "Psychoneuroindoctrinology".

Posted by Mark Liberman at April 4, 2007 08:49 AM