Across dozens of sports, women's world speed records consistently fall 10 percent short of men's records.
South Africa's Caster Semenya runs past the Olympic flame in her women's 800m round 1 heat during the London 2012 Olympic Games (Reuters)
Earlier this week, we set out to test our perception that women were catching up to men. We know, after all, that there are and were structural factors that prevented women from engaging in and training for athletics. Our perception was that these impediments had been getting slowly eroded. Therefore, we expected to see, at least in some sports, a path to equality that showed women's times catching up with men's in 2031 or some other date in the future.
But when we went to the data, our hypothesis didn't hold up. In a set of swimming and running races, each women's world record was about 90 percent of the men's world record.
It turned out someone had already conducted similar -- and broader -- research on this ratio. The Israeli physicist Ira Hammerman spoke at the 2010 Wingate Congress of Exercise & Sports Sciences, and he found that this little-known ratio held across all sports.
Running. Swimming. Rowing. Kayaking. Short distance, long distance. Accomplished in teams or attempted alone.These are such diverse events, requiring different parts of the body and diverse types of talent. And yet they all share something: Their women's speed world records are all about 90 percent of their men's speed world records, in both short, middle and long distances.
In kayak racing -- played solo or in teams of 2 or 4; at distances of 200m, 500m or 1000m -- the mean ratio between women's and men's records was .88. In track cycling, at short or endurance distances, women's records were 88 percent of men's.
Even in crew rowing -- a sport for 1, 2, 4 or 9 people, with two different forms of rowing and two different average weights -- the mean ratio from men's over women's world records was .90.
Hammerman looked at a total of 82 events in all, across six sports, and the difference between all of their records fell between .84 and .94:
Does this tell us something about the genders?
When talking about world records, we're always talking about the most accomplished human specimens. These aren't ordinary men or women. To arrive at any lesson about the basic difference between the genders, you have to jump a little, from the best to all.
And there could be social factors that shrink the available pool of women out of which the best athletes can emerge. In the US, let alone in other areas of the world, women make up only 41 percent of high school athletes.
At the same time, the 10 percent difference is clear from sport to sport and does not appear to be closely correlated with overall women's participation rates in athletics. Regardless of specifics, the factors which separate men and women probably seem to be, in Hammerman's words, "simple and basic."
Taking a kind of wild shot at which biological factors might affect athletic performance, Hammerman looked at hemoglobin counts and the maximum amount of oxygen an athlete can use in a minute.
And guess what he found? Men have an average of 13.6 to 17.5 grams of hemoglobin per decalliter in their blood. Women have 12.0 to 15.5 g/dl.
The ratio? .88 to .89.
And while maximum oxygen consumption statistics are harder to measure and harder to come by, if you compare them for four accomplished long distance runners of each gender, they average to 72.7 for women and 82.1 for men. 72.7 is about 89 percent of 82.1.
So, will women ever catch up to men?
There are two possible answers to this question. The most obvious interpretation is that no, women are not catching up to men. The data is converging on this ratio: in every sport that can be measured this way, the peak performance of the world's best female athletes tops out at around 90 percent of the peak performance of the world's best male athletes. In the 100m dash, by Hammerman's charting, this rough ratio has held for 55 years:
Don't be confused by the x-axis: it's counting years, though they may look like ratios. That 1/55 means January 1955. (Ira Hammerman)
And this trend has held for decades in most sports.
The second answer is that women have already caught up to men. Women today, for example, swim as fast as men did forty years ago. The women's world record for butterfly ties Mark Spitz's 1967 record.
While this work does not tell the tidy story of rising gender equality that we anticipated, it may have an unexpected and fascinating use. Hammerman believes you can use this data to predict when a new record should be penciled into the books. Because the 90 percent ratio should hold, Hammerman proposes, you can use it to guess which records might be the next to fall. If the women's record is lower than usual -- say, .85 of the men's, then there's likely room for improvement in the women's record. And likewise, if the women's record stands somewhat higher than 90 percent -- .93, .94 or .95 -- the men's record can likely improve.