Isotope analysis
A recent development in forensic science is the isotopic analysis of hair strands. Hair has a recognisable growth rate of 9-11mm per month or 15 cm per year. Human hair growth is primarily a function of diet, especially drinking water intake. The stable isotopic ratios of drinking water are a function of location, and the geology that the water percolates through. Sr, Sr and oxygen isotope variations are different all over the world. These differences in isotopic ratio are then biologically 'set' in our hair as it grows and it has therefore become possible to identify recent geographic histories by the analysis of hair strands. For example, it could be possible to identify whether a terrorist suspect had recently been to a particular location from hair analysis. This hair analysis is a non-invasive method which is becoming very popular in cases that DNA or other traditional means are bringing no answers.
Hair fetishism
Hair is one of the defining characteristics of mammals. In humans, hair can be scalp hair, facial hair, chest hair, pubic hair, axillary hair, besides other places. Men tend to have hair in more places than women. Hair does not in itself have any intrinsic sexual value other than the attributes given to it by individuals in a cultural context. Some cultures are ambivalent in relation to body hair, with some being regarded as attractive while others being regarded as unaesthetic. Many cultures regard a woman's hair to be erotic. For example, many Islamic women cover their hair in public, and display it only to their family and close friends. Similarly, many Jewish women cover their hair after marriage. During the Middle Ages, European women were expected to cover their hair after they married, and according to the New Testament, a christian woman should cover her head while in a church or in prayer.