Why do some people have straight hair and some have curly?
It has to do with the temperature of which the person and their ancestors have lived. Striaght hair is a sign that the person has lived in a cooler climate, because it will lay flat to conserve body heat. Curly hair is known as a heat coil, meaning that it disperses heat more rapidly. Pepole from arctic regions have straight, oily hair. People who live in desert regions like the desert or in africa have curly hair to disperse the heat.
