It has been a while since I posted, and that is partly because I have been on spring break vacation with my wife and kids. We went to Disneyland (Yuck.) Whenever I am someplace where there's a lot of people, I tend to get into people watching mode. And as someone who is very interested in the way people move, my people watching mode involves watching people move. Now of course I get the chance to do this in many places, but one of the advantages of Disneyland (and the airports that get you there), is that you can watch families moving together. Which allows you to compare movement and posture patterns between members of the same family. So fun right?
Whenever I noticed someone with a particularly distinctive posture or gait, I immediately looked over to see if anyone else in the family had the same pattern. Some of the resemblances were so striking, that when I pointed them out to my wife she said: "Hmm."
For example, I saw a 40 year old woman with very hunched shoulders and a forward head. Many therapists would look at this posture and assume it results from some bad (and changeable) habit of use. But when you see the exact same posture on her ten year old daughter, you have to wonder how much of it is due to genetics.
Nature or Nurture
Of course some people will say the daughter may be imitating her mother. Now I don't have specific research to refute this explanation, but it does not strike me as very plausible. Babies learn the movement basics (rolling, creeping, crawling, deep squatting, standing) not by imitating their parents (who aren't doing these things), but by trial and error. And once kids are in school, in general, they imitate their peers, not their parents. For example, even toddlers talk with the accent of their friends, not their family. I would guess kids try to move and posture themselves like their peers as well. This is particularly obvious in the teenage years, where social signaling through body language becomes very important. So when I see many family members moving the same way, I favor genetic explanations.
I actually did not need to go to Disneyland for this type of observation, because one branch of my wife's family is a good example. If you go to a party with this side of the fam, you will notice that many of them like to stand with the pelvis translated forward and tucked under into posterior tilt. Do they all stand this way because they imitated each other, or is this posture simply an inviting way to stand when you have the structure that is dictated by their common genetics? Who knows, but again I favor the structural explanation, because the few family members without the distinctive family structure do not share the distinctive family posture. I better stop now before getting into trouble.
What do you think? Are posture or movement similarities between family members due to environmental or genetic influences? Do people imitate their peers movement wise? Anyone have any interesting family stories? Let me know in the comments.