map (function, iterable, ...) Â¶ Apply function to every item of iterable and return a list of the results. If additional iterable arguments are passed, function must take that many arguments and is applied to the items from all iterables in parallel.
The grey hair ârule of thumbâ is that by the age of 50, half of the population have lost the colour in 50% of their hair. When researchers tested this rule, they found that 74% of people aged between 45 and 65 had grey hair, with an average intensity of 27%.Generally, men have more grey hair than women.he grey hair ârule of thumbâ is that by the age of 50, half of the population have lost the colour in 50% of their hair. When researchers tested this rule, they found that 74% of people aged between 45 and 65 had grey hair, with an average intensity of 27%. Generally, men have more grey hair than women.
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 their hair. When researchers tested this rule, they found that 74 per cent of people aged between 45 and 65 had grey hair, with an average intensity of 27 per cent.o, stress DOESN'T turn your hair grey and men's beards really DO go ginger: Expert reveals what really affects our hair colour. 1  Rodney Sinclair is a Professor of Dermatology at University of Melbourne. 2  Claims that by age 50, half of us have lost colour in 50 per cent of our hair.