article_snippet: Ever wondered why we go grey or most men's beards have a reddish, ginger tinge?
article_snippet: The Duchess of Cambridge battles with grey hair, as these pictures reveal. 
article_snippet: Genetic factors appear to be important in determining when we turn grey, rather than lifestyle, says Professor Sinclair .
article_snippet: Most of us find us first 'greys' by the time us turn 30, usually at the temples, then later, across the scalp .
article_snippet: How grey is really grey?
article_snippet: Most of us find us first 'greys' by the time us turn 30, usually at the temples, then later, across the scalp.
article_snippet: The grey hair 'rule of thumb' is that by the age of 50, half of the population have lost the colour in 50 per cent of half of the population hair.
article_snippet: When researchers tested The grey hair 'rule of thumb, researchers found that 74 per cent of people aged between 45 and 65 had grey hair, with an average intensity of 27 per cent.
article_snippet: Generally, men have more grey hair than women.
article_snippet: Asians and Africans have less grey hair than Caucasians.
article_snippet: By the age of 50 (Ben Affleck, 42, is pictured left and Colin Firth, 54, right), half of us will be 50 per cent grey, says Professor Sinclair. 
article_snippet: Generally, men have more grey hair than women .
article_snippet: Genetic factors appear to be important in determining when we turn grey.
article_snippet: Identical twins seem to go grey at a similar age, rate and pattern, however we're yet to identify the controlling genes.
highlights_snippet: Claims that by age 50, half of us have lost colour in 50 per cent of our hair .
  