American film director, screenwriter and novelist Nora Ephron is behind one of the most revealing quotes about women's enduring youth appeal and success in the workplace: "There's a reason why forty, fifty, and sixty don't look the way they used to, and it's not because of feminism, or better living through exercise. It's because of hair dye.
In the 1950s only 7pc of American women dyed their hair, and today there are parts of Manhattan and Los Angeles where there are no grey-haired women at all."
It seems men in the US are now beginning to fight back at the recession by following women's lead in their battle for career success, and by dyeing their hair more -- and where Los Angeles leads, European capitals eventually follow.
Jeff Swaner, who owns Epic Salon in Los Angeles, has revealed that 40pc of his male clients are now having colour treatments, more than twice as many as two years ago.
"They don't want to have age as a barrier, and this is one of the ways that they can look a little younger and feel more comfortable about going in and interviewing for a job," he said.
The striking element of this new trend of men dyeing their hair is that they want to keep just a little grey in their colour. They hope this will indicate to potential employers that unlike the young buck beside them, they have experience, do not require training, and can hit the ground running.
Dublin stylist Paul Hession says: "I'm seeing this in how men don't go for a block colour the way women do, but go for a comb-in colour which disguises the fact that they are going grey. It's the salt and pepper look. Men are going greyer and balder younger. Going grey can be hereditary or stress-related." Men in their thirties look for a little help in keeping a youthful appearance at his salon in Clontarf.
Paul says: "A lot of male clients would be the husbands or boyfriends of the women we style and, while I haven't a figure on it, an increasing number are looking to have their hair coloured.
"What I will say to men is not to forget the grey around the sides. When the sides are grey and the rest isn't, it just looks like a man has forgotten to touch up the sides with colour.
"Job interviews are really important today, so it makes sense that a man will want to look his best on the day," he says.
Grey hair was once thought to make a man look distinguished, and George Clooney (left), Richard Gere and Harrison Ford have often been cited as mature men who have not lost their sexiness in spite of going grey.
However, with the job market more competitive than ever, men are finding that defying the grey can help when it comes to bringing home a salary.