babies of smoking mothers versus babies of non-smoking mothers.
Overall, But just babies of smoking mothers to
their siblings when the mother was not smoking.
In this case, within the shibship, there's no effect of maternal smoking.
That is, the mother who smoked when she had a child, when she did
smoke while pregnant And she had a child while she didn't smoke while pregnant.
There was no difference in the risk of ADHD to those two children.
Smoking did not appear...does not appear does not appear to be a causal
influence on risk to ADHD because you don't get the within sibship effect.
Why is it associated then overall?
It's associated overall because there are other factors that may be...must
be correlated with maternal smoking that are really the causes here of ADHD risk.
What might those be?
I mentioned those in the previous slide.
Those might have to do with the The home
environment or it might have to do with genetic
factors, but maternal smoking per se does not appear
to be causal because you don't get the within-family effect.
So, parental behavior is related to offspring functioning.
But what a behavioral geneticist will want to emphasize is the mere observation of a
correlation between parent behavior and offspring functioning
doesn't isn't the basis of some causal inference.
That could be for genetic reasons, it could be for environmental reasons.
We don't know just be observing the correlation.
You're going to, you shouldn't allow me, if somebody reported a study
that said, highly religious parents tend to have highly religious children, and
I came along and said, oh,
there's a parent-offspring correlation in religiousness,
that must be genetic, I would hope that you would challenge me.
Because that correlation by itself can't be
the basis for a strong causal conclusion.
What I'm arguing at the same time is, if I observe a correlation between parent
religiousness and offspring religiousness, I'm not going to let
you say that that necessarily is environmental either.
You need more evidence.
Where that additional evidence is going to come from often from behavioral genetic
studies, like the within sibship study I gave you previously in this module.