FACEBOOK'S chief operating officer Sheryl Sandberg has launched a fierce attack on the gender stereotypes that hold back women at work.
Addressing the World Economic Forum in Davos, Switzerland, Ms Sandberg, who is publishing a book called Lean In on women in the workplace, singled out T-shirts sold in the US with the boys' version emblazoned with the words ''Smart Like Daddy'', while the girls' version says ''Pretty like Mommy''.
''I would love to say that was 1951, but it was last year,'' she said. ''As a woman becomes more successful, she is less liked, and as a man becomes more successful, he is more liked, and that starts with those T-shirts.''
She blasted managers who unconsciously reflect stereotypes when they judge women's performance, saying, ''She's great at her job but she's just not as well liked by her peers'', or, ''She's a bit aggressive''.
''They say this with no understanding that this is the penalty women face because of gender stereotypes.
''Women still have two jobs in the most developed countries around the world; men have one. From the moment they leave school, the messages for women are different: 'Don't you want to have kids one day?' ''
Ms Sandberg was appearing at a panel session in Davos, where five of six speakers were female - the opposite of the gender balance at many Davos events.
Only 17 per cent of delegates at the high-powered event are women and, in an effort to increase female numbers, the organisers now insist the top 100 ''strategic partner'' companies that attend and which can bring five delegates each must include one woman. Many, however, choose to bring only four rather than include a female executive.
The International Monetary Fund managing director, Christine Lagarde, said her experiences of overcoming prejudice had helped her to be a better boss. ''I grew up with brothers; I grew up in a man's world, and you had to elbow your way in,'' she said.
''I listen more; I'm more attentive to those in the back of the room that sit in the dark and don't want to talk but have a lot to contribute.''
She said women made better team players: ''It's because of our history, it's because of our heritage, it's because of what we've had to face.''
The European Commissioner for Justice, Fundamental Rights and Citizenship, Viviane Reding, had earlier presented data showing women made up 15.8 per cent of company boards in Europe, up from 13.7 per cent a year ago.
She said companies had been forced to become more diverse by the European Commission when it declared it would legislate to improve the situation. ''Since the moment that I threatened that if there was no progress then I would put up legislation, there has been real progress,'' she said. ''Sometimes it needs a little push.''
Ms Reding added that it was crucial for workers to be provided with proper childcare. ''This is an issue for men as well as women.''
Elsewhere in Davos, the European Central Bank president, Mario Draghi, said the optimism surging through the stock exchanges of Europe showed that normality was returning.
But he did not expect the economic recovery to begin until the second half of this year.