08 March 2006

Wrist-walking humans

wrstwlkrA case study1 of five siblings who are wrist-walkers has come to my attention. The individuals (4 females, 1 male), all adults from a village in southern Turkey, have never developed bipedalism; instead, they walk and run on their feet and wrists with palms, but not the fingers, contacting the ground. According to the study, they all have a congenital brain condition and are mentally retarded. Interestingly, another sibling with the same cerebral symptoms walks upright.

There are 2 unfortunate aspects of the story. First, the authors report that these individuals, although accepted by their family, are teased and laughed at by the other villagers. Second, they don’t appear to have received any form of physical therapy that might have helped them develop bipedal walking.

At the end of the paper, there is a brief discussion of the evolutionary implications of this particular case. The authors mention that wrist-walking might have been an intermediate stage during the evolution of bipedalism from quadrupedalism. And then, they go on to speculate that "in these modern human quadrupeds, we are indeed seeing the 'rediscovery' of something very like the quadrupedal gait used by our ancestors." Well, I don’t think I would go that far based on one case. To me, this sounds more a like a case of infants with developmental problems imitating their older siblings to do the best they can in the absence of proper medical care and early intervention.

Note added later: Afarensis has posted a more detailed review of the subject.


1. Nicholas Humphrey, John R. Skoyles, Roger Keynes. 2005. Human Hand-Walkers: Five Siblings Who Never Stood Up. CPNSS Discussion Paper DP 77/05. pdf

3 comments:

afarensis said...

That's my take on it too

fish without faces said...

how are we eldest siblings to feel about all this? I've always told my brother and sister not to follow my example.

I read that the family was left with a new well after the whole thing.

eped said...

how are we eldest siblings to feel about all this? I've always told my brother and sister not to follow my example.

I read that the family was left with a new well after the whole thing.