It would be nice if you had the sexes of the siblings, since it’s supposedly only the older brothers that count, though I don’t really expect that to change anything.
Really the important thing is just to separate birth order from family size. Usually the way I think of this is, we can look at number of older brothers, with a given number of older siblings. I like this setup because it looks like a randomized trial. I have two older siblings, so do you, meiosis randomizes their sexes.
But I guess with the data you have you can look at birth order with a given family size, so we don’t have to worry about the effect of a larger or smaller family. I… don’t think this is what you did? Did I misunderstand something? It seems like if cardinals come from smaller families, that would show up as lower birth orders.
With 9 million people I’d just split it into categories by number of siblings, with your data I’m not sure.
It would be nice if you had the sexes of the siblings, since it's supposedly only the older brothers that count, though I don't really expect that to change anything. I wanted to do that but given the Ablaza et al. results where the effect exists for all older siblings, I decided it wasn’t worth the drop in power.
It would be nice if you had the sexes of the siblings, since it’s supposedly only the older brothers that count, though I don’t really expect that to change anything.
Really the important thing is just to separate birth order from family size. Usually the way I think of this is, we can look at number of older brothers, with a given number of older siblings. I like this setup because it looks like a randomized trial. I have two older siblings, so do you, meiosis randomizes their sexes.
But I guess with the data you have you can look at birth order with a given family size, so we don’t have to worry about the effect of a larger or smaller family. I… don’t think this is what you did? Did I misunderstand something? It seems like if cardinals come from smaller families, that would show up as lower birth orders.
With 9 million people I’d just split it into categories by number of siblings, with your data I’m not sure.
It would be nice if you had the sexes of the siblings, since it's supposedly only the older brothers that count, though I don't really expect that to change anything.I wanted to do that but given the Ablaza et al. results where the effect exists for all older siblings, I decided it wasn’t worth the drop in power.