The Grandmother Effect, with colorful, inclusive illustrations, is a great gift for Grandparent' s Day or any day!This heartwarming and beautiful book celebrates the bond between grandmothers and grandkids. When grandmothers and grandchildren get together, they share cozy moments and daring events, important milestones and ordinary afternoons. Not only is time spent with gram special-- it' s also pretty rare!Humans are among a small group of animals that enjoy grandmas and multigenerational family life. In fact, scientists who study human evolution have determined that, thanks to grandmothers, our human species was able to develop large brains, form social groups, and live long lives. The Grandmother Effect, written by Beth Bacon and illustrated by Kat Bourek, is a tribute to today' s grandmas as well as those ancient grandmothers who allowed us to develop advanced human traits.