Can dummies make the best teachers? Medical students are increasingly being trained on high-fidelity mannequins that bleed, sweat … and even give birth. Their “bodies” offer simulations that help trainees practice high-stress medical crises in low-stakes environments. The hope is that these “patients” will help reduce medical errors — reportedly the third-leading cause of death in America. Studies show they help boost confidence, but with price tags hovering around six figures and murky findings on whether they reduce mistakes, some wonder whether dummies are the smartest choice.