Razib Khan One-stop-shopping for all of my content

May 4, 2017

In grip strength a woman in the 90th percentile would be at the 10th percentile for men

Filed under: Grip Strength,Sex Differences,Sports — Razib Khan @ 11:44 pm

In relation to the title of this post, it is more accurate to say that a 35 year old British woman who is in the 90th percentile, at 39 kg, would be at the 10th percentile in 35 year old British men. But she would be at the 50th percentile for a 70 year old man. Another way to look at it is that an average 35 year old woman is as strong as an average 80 year old man.

Also of interest, 90 year old men have stronger grip strength than 10 year old boys (25 kg vs. 17 kgs) but 90 year old women have weaker grip strength than 10 year old girls (14 kg vs. 16 kgs). There is a major difference in life trajectory. Men and women start off with the same upper body strength as boys and girls in elementary school. But between ages 10 and 30 years men really outpace women.

Here’s a chart I constructed from the data with male an female at 10th, 50th, and 90th, percentiles:

Look at what happens to girls/women in the 90th percentile between 10 and 30. Because girls develop faster they are highly competitive with boys up until around 15, and then the “great grip divergence” kicks in. Both men and women get stronger between 20 and 30 (to my surprise), but men gain a lot more. At age 30 in standard deviation units the average women is about two standard deviation units below the average man. This would put the average women at the 2.5th percentile of men assuming a normal distribution. The raw table is below the fold at the bottom of this post. The paper is Grip Strength across the Life Course: Normative Data from Twelve British Studies.

The data to the left are from the paper Hand-grip strength of young men, women and highly trained female athletes. It is a German study, and compared three populations: normal men, normal women, and elite national level athletes in Germany in judo and handball. Judo and handball were selected because grip strength are at a premium in these two sports.

To their surprise the average female athlete was at the 25th percentile for males.

Many people will find this post a bit ridiculous. Who doesn’t know that men aren’t stronger than women?

First, there are some academics who believe that increased training will allow women to converge with men in strength, and therefore they propose to end sex segregation in sports. Proponents of this view say thinks like this:

Could that change? Could women start catching up with men again? After all, people used to say women were unable to handle political office. Even the slowest-converging lines eventually do merge; the truth is nobody knows for sure if that’s the case here. The history of women in sports is a history of being gradually allowed access to social privileges which have made them better athletes, and there could yet be undiscovered factors at play that could make the gap smaller.

There’s no comparison between political office and athletic performance. Second, the slowest converging lines do not eventually merge by necessity.

Second sometimes it is good to have numbers. I am not in the habit of getting into fights with women, ten year olds, or senior citizens, so I don’t have a quantitative grasp of how I “stack up.” I don’t beat my children so I don’t have a good sense of how much stronger than them I am, though my parents did beat me on occasion so I have an intuition about how it is on the other end. My grip strength is probably five times greater than my daughter’s. Good to know.


October 16, 2011

Individual differences don’t lie

Filed under: N.B.A.,Sports — Razib Khan @ 4:16 pm

Over at Think Progress there’s a piece titled Why We Can’t Dismiss The NBA Labor Dispute As ‘Millionaires Versus Billionaires’, where the author argues that the players are fundamentally different than the owners in relation to the acquisition of their wealth. There’s a whole lot of prose there, but the first commenter really hit the nail on the head: Chris Rock solved this shit years ago (and you just read that in his voice) – “The guys on the court are RICH. The guy sitting up in the box is WEALTHY.” If you magically multiplied the players’ salaries by a factor of two all that would do is that push back the likelihood of bankruptcy by 5 years or so. An added cushion would take more time to burn through, but that would be compensated for the fact that signalling consumption would increase. In other words, instead of 8 cars in the garage, 16. Instead of an entourage of 6, 12.

Consider someone like Antoine Walker. He’s still trying to maintain a professional career when it’s pretty obvious he doesn’t have the skills due to his age. But he’s got to service his debts. Would doubling Walker’s salary have made a difference at the end of the day? I doubt it.

This isn’t an argument for paying professional basketball players any less. Professional sports teams seem more like a luxury consumption good for most owners (Donald Sterling excepted). Their consumption habits certainly have a stimulative effect, though it seems that financial mismanagement and fraud are extremely common events in the careers of these athletes. Because they lack sophistication the slickest and slimiest lawyers and accountants seem drawn to them. But it just seems foolish and evasive to admit that these individuals lack the basic skills to manage huge windfall incomes for a few years, and not propose any policy response if you think that their inevitable fates should be avoided. If you want to increase long term player well being then you’d want their contracts to be negotiated so that salaries would be disbursed over 20 or 30 years, with trustees who could release funds in case of an emergency (e.g., health costs, or expenditures in the face of immanent death). You’d need to go very paternal.

Greece, the American consumer, and our financial sector simply couldn’t handle massive capital inflows responsibly. We expect N.B.A. players who tend to exhibit high time preference to be saved by extra millions of dollars? Get real.

June 12, 2011

Taking one’s talents to South Beach

Filed under: LeBron James,NBA,Sports — Razib Khan @ 6:56 pm

So It didn’t work out for LeBron this year. I suspect it will work in the near future. Remember that it took Shaq and Kobe four years to win their first championship. Talent doesn’t guarantee a championship, but it sure does increase the odds. For now though I’m savoring. Though perhaps not as much as the people in Cleveland.

May 30, 2011

Hope before the fall

Filed under: Jason Kidd,NBA,Sports — Razib Khan @ 10:08 pm

I think it is pretty irrational to bet on the Mavericks against the Heat in the NBA Finals. And since my Celtics lost I haven’t been following what’s going on closely, but I hope Jason Kidd gets his ring. He’s had some ups and downs, but I do remember being amazed by him when he was a freshman at Cal (though watching tape of Magic it was clear that he had the same panache when it came to assists):

April 2, 2010

Why Dukies underachieve as pros

Filed under: Sports — Razib Khan @ 4:01 pm

Interesting article in Slate. This shocked me:

Out of all the big schools, NBA teams likely fall harder for Dukies because of their NCAA tournament success. In Stumbling on Wins, economists David J. Berri and Martin B. Schmidt find that players who appear in the Final Four the year they’re drafted get a boost of 12 draft positions. Berri and Schmidt believe that this boost is unwarranted. One of the “statistically significant factors … that lead to less productivity in the NBA,” they write, is “playing for an NCAA champion the year drafted.”

I’ll have to look at the model itself, but this is somewhat surprising if plausible. It makes intuitive sense, but NBA teams don’t normally take the draft lightly and do prep work. On the other hand, as the years go by I’ve become more skeptical about the ability of institutions to squeeze all efficiencies out of any given process (I suspect there’s a principal-agent problem; those who are making the final call are less likely to get fired if they select a “can’t miss” who they think is overrated if that prospect flops than if they get someone who they believe is underrated, and it turns out their assessment was in error).

Personally, I think the similarities between Duke and Indiana during the Bobby Knight years are telling, and Knight was a mentor of Mike Krzyzewski. Both schools seem to produce fewer stars on the professional level in relation to the success of their teams; but I think the group vs. individual dynamic is key. There are differences between the pro and collegiate level, and Duke and Knight’s Indiana teams were able to leverage group level efficiency and precision in collective action to make up for shortfalls in relative individual talent. When a team manages to win many games individual players are perceived to be better than they are. Take individuals out of that context and their more modest talent endowments become obvious. A college team which routinely makes it far in the NCAA tournament can regularly field what might be “role players” at best in the NBA.

January 21, 2010

How much faster

Filed under: Sports — Razib @ 1:29 am

Athlete Atypicity on the Edge of Human Achievement: Performances Stagnate after the Last Peak, in 1988:

The growth law for the development of top athletes performances remains unknown in quantifiable sport events. Here we present a growth model for 41351 best performers from 70 track and field (T&F) and swimming events and detail their characteristics over the modern Olympic era. We show that 64% of T&F events no longer improved since 1993, while 47% of swimming events stagnated after 1990, prior to a second progression step starting in 2000. Since then, 100% of swimming events continued to progress.

We also provide a measurement of the atypicity for the 3919 best performances (BP) of each year in every event. The secular evolution of this parameter for T&F reveals four peaks; the most recent (1988) followed by a major stagnation. This last peak may correspond to the most recent successful attempt to push forward human physiological limits. No atypicity trend is detected in swimming. The upcoming rarefaction of new records in sport may be delayed by technological innovations, themselves depending upon economical constraints.

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