One of my male friends was recently teasing me about the results of a study by Dr. Claudia Wolf of Ruhr University in Germany in which she had 65 participants - men and women - park Audi A6s in "standard size parking spaces." Dr. Wolf claimed that results showed that (1) women parked more slowly than men, and (2) women were less accurate than men (men were able to maneuver the cars to the middle of the space better than women).

This study has achieved a fair amount of attention on the internet - as of the writing of this entry, the original Telegraph article had been dugg more than 1,000 times. Considering the popularity of John Gray's Men are from Mars... and similar "psychology of gender" type research, this should come as not surprise. But what is at least slightly surprising - and endlessly frustrating - is the jump to overgeneralization and claims about fundamental gender differences.

I'm rather partial to the topic of gender (full disclosure: my thesis dealt with perceptions of gendered communication in emails), so this is a personal frustration for me. Notably, the most respected research in the field of psychology suggests that gender differences in abilities are not particularly meaningful or consistent (e.g., Hyde, 1981Hyde&Lynn, 1988). What is much more meaningful are gender differences in norms, stereotypes, and expectations and how those differences translate into segregating the workforce (more men in math, science, and engineering; fewer women leaders; fewer women in highly paid positions, such as CEOlower salaries for women).

Men are from Mars, Women are from Venus
Traveling Mars and Venus, from a blog on the UK's Mirror

The other major methodological issue with Dr. Wolf's study is one fundamental to any claims of general group differences - the ability to generalize across people based on the sample of a few. While this is always an issue in psychology and statistics, the problem here is that to claim that these differences exist, Dr. Wolf needs to show that they exist across age groups and cultures - or at least address the idea that they may not. It's well-established that our perceptual capabilities change as we age (there are fundamental changes in the brain as we age), so it's reasonable to question whether the men and women in the sample were the same age... were they all pre-tested to determine whether they were equal in these perceptual capabilities?

If you look at the gender research in general and that I've cited here, you'll notice the continual warnings about not generalizing findings related to gender differences across culture (note the Wikipedia warning that the article may not represent a worldwide view). In fact, a lot of gender research (that I'll admit I like a lot) poses that differences in culture and roles are the real cause of supposed gender differences (see Eagly's 1987 book or any of her work). The same is relevant here - were all the participants born and raised in Germany and is the expectation that both teenage boys and girls learn to drive? Or do females tend to learn to drive later in life (thus leading to less experience despite the same chronological age)?

And is there an expectation that females are worse drivers than males (as Dr. Wolf indicates by saying she intended to test the myth/rumor/urban legend)? Stereotype threat research (see Claude Steele's work) shows that expectations strongly influence performance - such as when test-takers are told that women do worse on the math test they are about to take and then women subsequently perform worse - so it's reasonable to assume that expectations can influence performance - which means that there are NOT gender differences in perceptual/cognitive capabilities. The fact that women took longer to park could be evidence that stereotype threat is at work - if women think they are going to do worse, they may go slower and be more deliberate in an effort to be more accurate (which may or may not actually lead them to be more accurate since the only thing the study showed is that women were slower and less accurate - NOT that slower women were less accurate than faster women).

But perhaps all of these concerns will be addressed when Dr. Wolf finally writes this all up in an article for a peer-reviewed journal. Or maybe these flaws will make it unpublishable (as no citation is listed for future publication of the study).

Note: I do my best to cite sources that are readily available on the internet, but sometimes I do cite what I know or have read because it's easier and/or a better fit, in which case I try to link to an abstract that is widely available and sometimes resort to Wikipedia (when it matches up with what I've read in peer-reviewed journals, it seems to be a good way of concisely summarizing and supporting a point). That's what you'll get when you click on the links associated with the sources.  My apologies for not being able to offer the entire text - being young and poor makes it difficult to figure out a way to do that...

Original Article: Matthew Moore's December 20, 2009 article "Women worse at parking than men, study shows" appeared in the UK'sTelegraph, link found here.

(Originally posted here by yours truly.)