Friday, September 23, 2011

Sex Pheromones by the Numbers: Have They Peaked?

I recently declared that I no longer find the concept of human pheromones to be scientifically useful. I think there is lots of evidence for the effect of scents on human cognition, behavior, and physiology. But if we insist on labeling all these various effects as pheromones, we muddy the intellectual waters and make it harder to understand the biological basis of the effects. Dick Doty, in his book The Great Pheromone Myth, has done an impeccable job of showing how intellectually bankrupt the pheromone concept has become.

Still, there are die-hards out there who believe that with enough gas chromatography-mass spectrometry and with fine-grained enough fractionations, they will isolate the magic molecule that Will Drive Women Wild. Their more restrained colleagues believe that more research may lead to a mixture of a few different molecules that, when applied to a female with a specific mating history, at a specific time of the month, may, under certain specified conditions, alter her perception of men. For them, sex pheromones are a mixture that Will Drive Women to a Statistically Significant Difference in Perception.

Not exactly the stuff of lurid fantasies . . .

My sense is that many scientists in the field privately agree with Doty’s critique; it’s just not politic to trash the concept when you are applying for grant funding to study sex and scent.

It’s also my sense that public enthusiasm for pheromones has cooled. To test my impression, I played with a program from Google Labs:
When you enter phrases into the Google Books Ngram Viewer, it displays a graph showing how those phrases have occurred in a corpus of books (e.g., “British English”, “English Fiction”, “French”) over the selected years.
Neato! So let’s enter “pheromone” and ask for results from the corpus of English books from 1950 to 2008. Here’s what we get:

We find that pheromone enters the charts soon after its coinage in 1959, and climbs steadily to a peak in 2000. After that, it’s all downhill.

Can such a widely credited concept go bust just like that?

In my review of Doty’s book I wrote:
Once upon a time instinct theory was equally in vogue and used to “explain” all sorts of behavior. Today it’s rarely invoked. By specifying the roles of context and learning, behavioral science simply outgrew the need to appeal to instinct.
So let’s put “instinct” in the Google Ngram Viewer, set the time frame for 1800 to 2008, and see what we get.

Interesting! Instinct enjoyed a long climb in usage throughout the 19th Century and into the first two decades of the 20th. (Darwin, Freud, yadda yadda.) But it peaked in 1921 and then sank like a stone.

Which leads one to wonder: was 2000 the high water mark for pheromones? My money says yes.

1 comment:

EdC said...


My 1984 Webster's New Collegiate Dictionary just says, "produced by an animal and serves esp. as a stimulus to other members of the same species for one or more behavioral responses." I agree that any definition broad enough to include a stimulated response of, "Phew, go take a shower!" doesn't deserve its own word.

The question that interests me is, are there any effects, "of scents on human cognition, behavior, and physiology," that are outside or below the level of consiousness?