Anna G. Warrener, Assistant Professor of Anthropology, did a study while at Harvard University to test the notion that wider pelvises in women decrease the efficiency of locomotion. After measuring the chain reaction of forces moving through the body—from the foot to the leg to the hip—Warrener and her colleagues found that wider hips do not increase the cost of locomotion. Indeed, both women and men are equally efficient at walking and running, and in hunter-gatherer societies, women walk, on average, 5.5 miles per day, often while carrying and feeding infants as well.