• Question: How come people from different countries are born with different coloured hair? Like for example Swedish people mostly have blonde hair or Chinese people mostly have black hair.

    Asked by 322susa22 to Ahmed, Francesca, George, James, Nitheen on 17 Nov 2014.
    • Photo: Ahmed Osman

      Ahmed Osman answered on 17 Nov 2014:

      I think this is from their genes but what I am sure of it is the colour of the hair depend on the number of carbon atom in the hair, so blonde hair has lower carbon atoms than in black hair


    • Photo: Francesca Paradisi

      Francesca Paradisi answered on 17 Nov 2014:

      This is very interesting and always fascinated me too. It has to do with the genetic pool in the various areas of the World. In Sweden, the majority of people is blond with blue eyes and as it’s more likely that they will marry someone else from Sweden with the same genetic traits, this will be conserved and propagated in the children. Same in China. However, some genes are recessive (blue eyes and blond hair) so if a Swedish person will marry a Chinese, it is very likely that the Chinese traits will prevail in the children.

    • Photo: James Sullivan

      James Sullivan answered on 17 Nov 2014:

      Hi 322,

      They are blonde in Sweden because their parents were blonde, and blackhaired in China because their parents had black hair.

      For thousands of years we’e tended to mate with people from our own area so these characteristics get reinforced.

      What makes it interesting is why were the Swedes blonde 1000 generations ago and the Chinese blackhaired. And all I can suggest is there was some evolutionary pressure to favour blonde people in Scandinavia, and favour blackhaired people in China.