Another consideration is parent-offspring conflict, which predicts that babies try to extract more care out of their parents than is optimal for the parents, perhaps enough of a difference to account for your surprise.
In terms of genetic interests this should reduce to male-female conflict, like birth weight, yes?
Not sure. They seem very much related, but the rationale for parent-offspring conflict applies equally well to parents of either sex (any unit of parental investment gives the child twice the benefit that it gives the parent because the child has only 50% of the parent’s genes). See the original POC paper here, and a paper on genomic imprinting (also by Trivers) here.
In terms of genetic interests this should reduce to male-female conflict, like birth weight, yes?
Not sure. They seem very much related, but the rationale for parent-offspring conflict applies equally well to parents of either sex (any unit of parental investment gives the child twice the benefit that it gives the parent because the child has only 50% of the parent’s genes). See the original POC paper here, and a paper on genomic imprinting (also by Trivers) here.