You’d have to do a study of whether children were more active before seatbelts became common. Which may be impossible. I would expect that children who spend less time in cars (i.e. who live close enough to school that they can walk) would be less likely to develop couch-potato habits.
You could study children living in places with very good mass transit compared to those living in places with little or no mass transit—the latter would be generally spending more time belted in.
You might even be able to find enough children who’d moved from one environment to the other so that if there’s a seatbelt effect, what the critical ages might be.
But mass transit has many other effects besides the seatbelts. For example, cars leave whenever you want them to, while public transport leaves at fixed times. In a bus or train there will often be many strangers, while there will usually be none in a car. Places with good mass transit might be that way for other reasons, like population density, terrain, wealth, political climate, etc.
I doubt you will be able to get a meaningful result about the activity of children in relation to seatbeltiness while controlling for all of these factors.
Side issue: cars leave when the person driving is willing to leave, which isn’t the same thing as being the driver yourself or dealing with mass transit schedules.
I’ve heard for New York and would find it plausible for other places with good mass transit, that New Yorkers do more walking than people in places with little mass transit.
It might be possible to sort out at least some of the confounding factors—not every city has good mass transit, for example.
That data should be possible to obtain, but there are some confounding factors—I can definitely imagine a family more inclined to drive than walk passing the factors that led to those preferences on to their children, for example. And I’m not sure how you’d control for that.
Most studies that try to separate genetic factors from “nurture” factors provided by the parents will twins that were adopted separately. It’s a small-ish subject pool though, and probably not recent since I don’t think they encourage separating siblings for adoption now.
I’ve wondered whether carseats and seatbelts end up training some children to accept not moving much.
You’d have to do a study of whether children were more active before seatbelts became common. Which may be impossible. I would expect that children who spend less time in cars (i.e. who live close enough to school that they can walk) would be less likely to develop couch-potato habits.
You could study children living in places with very good mass transit compared to those living in places with little or no mass transit—the latter would be generally spending more time belted in.
You might even be able to find enough children who’d moved from one environment to the other so that if there’s a seatbelt effect, what the critical ages might be.
But mass transit has many other effects besides the seatbelts. For example, cars leave whenever you want them to, while public transport leaves at fixed times. In a bus or train there will often be many strangers, while there will usually be none in a car. Places with good mass transit might be that way for other reasons, like population density, terrain, wealth, political climate, etc.
I doubt you will be able to get a meaningful result about the activity of children in relation to seatbeltiness while controlling for all of these factors.
It would be complicated, and you might be right.
Side issue: cars leave when the person driving is willing to leave, which isn’t the same thing as being the driver yourself or dealing with mass transit schedules.
I’ve heard for New York and would find it plausible for other places with good mass transit, that New Yorkers do more walking than people in places with little mass transit.
It might be possible to sort out at least some of the confounding factors—not every city has good mass transit, for example.
That data should be possible to obtain, but there are some confounding factors—I can definitely imagine a family more inclined to drive than walk passing the factors that led to those preferences on to their children, for example. And I’m not sure how you’d control for that.
Most studies that try to separate genetic factors from “nurture” factors provided by the parents will twins that were adopted separately. It’s a small-ish subject pool though, and probably not recent since I don’t think they encourage separating siblings for adoption now.
Did they ever encourage it?
It definitely used to happen a lot, judging by the sample size in twin adoption studies (usually 200-something pairs of separated twins).
Seems doubtful to me. It isn’t like you’d be walking around if you didn’t have a seatbelt on.
A seat belt considerably limits one’s ability to shift and turn, and a car seat is even more limiting than a seat belt.