By Tim Weber
Business editor, BBC News website, in Davos
Ms Fisher says a good business needs both male and female staff
When Helen Fisher speaks, the politically correct members of her audience are likely to flinch.
Declaring that she's "definitely not a feminist," the American anthropologist from Rutgers University dissects the differences between men and women.
Men are more analytical; women are better long-term planners.
Each gender has a different way of falling in love.
And the invention of the plough did more to set back gender equality than anything else since.
What Ms Fisher says is not psychobabble. She bases her findings on archaeological evidence, MRI brain scans, genetics and large-scale surveys of how men and women behave.
And understanding that male and female brains develop and behave differently is important not just if you are in the dating game.
It also helps us to hire the right people, improve teamwork and can - to quote part of the title of her talk at the World Economic Forum in Davos - grow a company's bottomline.
Once upon a time
Double-income families are not an invention of modern times.
Your ring finger apparently says a lot about you
"In prehistoric times, double-income families were the norm, and women provided 60-80% of the evening meal," says Ms Fisher.
But following the invention of the plough and with the resulting need for hard manual labour, the power balance shifted.
Only since World War I are women re-entering the workforce and regaining their status in society.
But there are much more fundamental differences between men and women, says Ms Fisher, that have been shaped over millennia of evolution.
For starters, men and women are thinking differently. Brain scans prove it, as does plenty of other research.
On average, women gather more data, consider the context, are intuitive, have a sympathising mind and think more long-term. Ms Fisher calls it "web thinking".
Men, on the other hand, are more focused, think linear, focus on rules and the short-term - "step thinking".
Blame testosterone for the difference. From the moment the embryo's brain develops in the mother's womb, high testosterone levels will make you focus on details in later life.
Blame your time in the womb if you aren't a great detail person
Now lift your hand and look at your palm. Is the ring finger longer than your index finger? Then you were the recipient of high levels of testosterone.
Chances are that you are an analytical thinker (or very musical), regardless of gender, while a shorter ring finger suggests you have a more sympathising mind. And men tend to grow up on lots of testosterone.
You want proof? Research shows that film scripts written by women are more complex and have more ambiguous endings than those written by men.
Male doctors focus on the illness and its treatment, while female doctors take a more holistic approach.
The long-term thinking of women makes them better investors.
It's even true in the bedroom, says Ms Fisher. Men tend to focus more on what they are doing, while women are easily distracted, she says to slightly embarrassed laughter from her audience.
And when men get older and their testosterone levels sink, their brain starts to work differently - they become more sympathetic to the plight of others.
But why the difference? Well, over the ages men tended to be the hunters and needed to focus.
Women, in contrast, had much more diverse tasks, like bringing up children (which Ms Fisher also believes may be the reason why women are better talkers: language is the key tool to control children).
The business case
So what does all this mean for business leaders?
Combine the long-term thinking of women with the short-term focus of men.
And bear in mind that different thinking also results in very different behaviour.
Men think more in terms of status and rank. Women prefer flat hierarchies.
Men can have tunnel vision, women may fail to get to the point.
Women find it difficult to counter aggression. When men push back, it earns them the respect of other men.
When women apologise, they are not really sorry. For men it's a serious affair, a perceived weakening of their status.
Ms Fisher's list goes on and on, but her message is clear.
Managers, says Ms Fisher, have to realise that men and women act differently, and that they complement each other.
Having only men or women on your team would be like hopping on one foot instead of walking.
As the status of women is on the rise again, says Ms Fisher, we "move forward to a lifestyle we had a million years ago".