Why do we go bald on our heads?

To stop Rosalind Davis pulling her hair out trying to get to the bottom of this, she asked Professor Robert Foley, from the department of Archaeology and Anthropology at the University of Cambridge to help her out.

Robert - We do lose hair from our heads and from our bodies throughout our lives. You only have to clean a shower out or a bath out to realise that that's true and, of course, we don't really notice or see the loss of hair on our bodies because the hair is miniaturised , very small and it's not very dense, the loss is virtually invisible. In addition, of course, it's replaced so we don't see a long term effect either on our bodies or our hair. If we turn to the bigger, and obviously more important question is the permanent loss of hair. In other words, going bald and there, there is a particular pattern to it. It is men, rather some men, who go bald. Why some men become bald is partly a matter of genetics. There seems to be quite strong evidence that there are genes, and those genes are on the X chromosome, and that produces a sex-linked pattern of inheritance. So that men inherit their baldness from their mother's father.

Rosalind - Surely though, as a species, we would have all evolved to keep our glossy locks.

Robert - It might well be that baldness has actually got some evolutionary advantage. Not many men feel that, but there have been studies showing that bald men can be seen as more attractive, often because it's associated with longevity, with success, wisdom, knowledge, maturity.

Rosalind - Okay, so if you are wise and mature but also, unfortunately, bald. Is there anything you can do?

Robert - In terms of doing anything about it, all one can really say is "buy a hat and be happy." That's almost certainly a signal of long term survival-ship as anything else.