> The human brain is constrained in size by the width of the female pelvis. https://en.wikipedia.org/wiki/Obstetrical_dilemma https://en.wikipedia.org/wiki/Obs

> The human brain is constrained in size by the width of the female pelvis. https://en.wikipedia.org/wiki/Obstetrical_dilemma https://en.wikipedia.org/wiki/Obstetrical_dilemma While the width is constrained by bipedal locomotion.