> I think it actually owes to Alan Previc.
> >This hypothesis originates with Dr. Bill Calvin who suggests that the
> >reason a mother would want to hold a baby on the left side is because
> >is where the heart is most audible.
Do you have a referrence on this? Calvin explicitly claims this hypothesis as his own, both in his book and in person. I talked with him at the Society for Neuroscience conference in New Orleans a year ago.