Were you one of those obnoxious kids who during story time always said; “It’s impossible for Rapunzel to pull up some guy with just her hair.” Well, turns out that the Brothers Grimm might've done some of their research.
Matt Spring, of Science Blogs, calculated how much weight Rapunzel’s hair would be able to support if you were to be climbed up a tower. He concluded that if the prince weighed a measly 63 lb, he would be able to climb human hair up a 90-foot tower. This of course, doesn't take into account that the weight of the hair and the prince would probably snap Rapunzel's neck pretty easily.
It's estimated that 150,000 strands of hair (estimate for an entire human head of hair) to support 2 full-grown elephants (2 tons).
Scientists believe that hair evolved for different reasons; for example, curly hair kept people cool in warm climates while straight care kept them warm in cool climates. Shiny and healthy hair is also an outward sign of health, making others see the person as an acceptable mate for the purpose of producing healthy offspring.
Maybe that’s another reason why that prince was willing to starve himself, and then risk his life to be with Rapunzel.