Years ago when Jamaican sprinters started to dominate the 100m/200m dashes, it was whispered that they had unusual jaw growth, some of them needing braces even in their early twenties. The allegation was that they used HGH, human growth hormone, that besides improving performance had side effects on the growth of extremities.
These side effect can occur naturally, usually if there is a tumor in the pituitary gland and very high amounts of growth hormone are created. This leads to a condition called Acromegaly, where jaw and brow ridge and basically everything else grows to almost grotesk proportions. André the giant may be most famous example, or Richard Kiel playing Jaws in the Bond movies.
At one of the recent Olympics, maybe 2012 or maybe 2016, I was struck by how similar the two superstars Micheal Phelps and Usain Bolt looked in terms of their body shape. Long, lean with a strong jaw and big hands and feet (Usain Bolt has shoe size 13, Phelps size 14).
I began wondering whether HGH-abuse, probably starting already in teenage years, was playing a major role in shifting the borders of human performance in high level sports. In swimming the never-ending flood of world records was explained by the improvements of full body swimming suits. Of course when these suits were banned records kept falling.
HGH leads to detectable changes in the facial structure. And Deep Learning methods allow us to turn pictures of faces into vectors that encode facial structures. This gives us a way to empirically assess whether faces of world class athletes have been shifted towards the facial structure typical for people suffering Acromegaly.
Because this is half-assed science and not full-assed science and there is, as always, a severe lack of graduate slaves, we will only manage a proof of concept. For this we select the male Olympic finalists in swimming for the years 1976, 1992 and 2016. These three years fall into three different phases of HGH-abuse: HGH has been used in high-level sport since 1982 and it was possible to detect it’s abuse since the early 2000s. So 1976 is pre-HGH, 1992 is HGH-time with no risk of being caught and 2016 is HGH-time with the theoretical possibility of being caught.
We also select the a couple of people suffering Acromegaly, as given by the wiki-article on the subject. And as a control group a number of normal guys, by googling ‚random guy‘ and ‚normal guy‘. We use a model that creates face embeddings, that is it detects faces in a picture and assigns vectors to these faces that encode facial structure.
We then compare the average face vector for our Olympic finalists and normal guys with the average Acromegaly face vector. Our results show that the distance to the facial structure typical for Acromegaly was biggest in 1976 with 0.671, smallest in 1992 with 0.625 and a little bigger than 1992 in 2016 with 0.634. The normal guys have on average a face 0.658 away from the Acromegaly face. The standard deviation of the distance of normal guys is 0.058, so the difference between 1976 and 1992 is 0.78 standard deviations.
This is certainly a big difference and the pattern of differences between 1976, 1992 and 2016 fit the different phases of HGH-abuse very well. The only thing that should give us pause is the fact that my normal guys are closer to the Acromegaly face than the 1976 athletes. More work is needed, but probably not by me!