From BMJ: "Tribal people do

From BMJ: "Tribal people do not like lying on the ground in the recovery position while wearing no clothes as the penis dangles in the dust and can get bitten by insects."  This is actually a very interesting article about how we humans are actually quite well engineered, yet the habits of Western Culture have changed our posture, sleeping position, etc ... so that we are much more prone to physical injury, back pain, etc.