In the first year only, 30 fathers were also interviewed, as were a small number of maternal grandmothers. (fatherhoodinstitute.org)
The preference for maternal grandparents starts early, with maternal grandmothers being more likely to be invited into the delivery room. (thespruce.com)
All of the birds in the third generation showed an immune response to the foreign protein, but the chicks that descended from maternal grandmothers who had also been injected mounted a significantly larger response, they report today in Biology Letters. (sciencemag.org)