I understand that the prevalence of infantile colic is around 15%. What I’d like to know is how heritable this is, to wit: how does the probability change if a sibling is known to have had colic? A parent? Etc. Of course this could be controlled for differing family sizes and other variables, I don’t expect a simple percentage.
A reference or two would be great; I’ve searched for various combinations of [colic sibling heritability] without any fortune thus far. (Strange, I would have thought this to be an easy question, maybe I’m doing or assuming something wrong.)