Quote:Baroness Susan Greenfield is one of Britain's best-known female scientists; she's a professor of neurophysiology at the University of Oxford, a former director of the Royal Institution and an accomplished writer and broadcaster on scientific matters.
So when she very publicly bemoans the lack of women reaching the higher echelons of the scientific establishment, people tend to sit up and take notice.
In a newspaper article last month, she expressed her concern that only ten per cent of science professors in this country are women.
Albert Einstein
Albert Einstein: Was he the perfect example of a male scientist being more intelligent than a female colleague?
Her comments struck a chord, attracting a host of comments agreeing that women scientists were generally getting a raw deal.
This raises an important and controversial question. Is there really a glass ceiling holding back the careers of talented female scientists? Have decades of anti-sexual discrimination legislation really counted for nothing in the laboratories of Britain?
Or might there be another explanation for why we find such a marked shortage of women, not just in the highest levels of science but in big business, the professions, and politics, too?
It is my contention - based on a lifetime of academic research - that there is an explanation and I advance it all too aware of the howls of feminist outrage I am about to unleash.
So, here goes: one of the main reasons why there are not more female science professors or chief executives or Cabinet ministers is that, on average, men are more intelligent than women.
Nor do the shocks to the noisy advocates of equal opportunities stop there, I'm afraid.
Baroness Susan Greenfield
Baroness Susan Greenfield
For not only is the average man more intelligent than the average woman but also a clear and rather startling imbalance emerges between the sexes at the high levels of intelligence that the most demanding jobs require.
For instance, at the near-genius level (an IQ of 145), brilliant men outnumber brilliant women by 8 to one. That's statistics, not sexism.
In this context, Professor Greenfield's indignation that only one in ten science professors is female doesn't seem all that bad. It also goes some way to explaining why, in almost 110 years of Nobel Prize history, only two women have ever won the Prize for physics, only four have won the Prize for chemistry and why no women at all have ever won the coveted Fields Medal for mathematics in eight decades of trying.
In recent years, the forces of political correctness have made the reporting of this sort of statistic virtually impossible.
Yet as a psychologist who has dedicated his career to the study of intelligence - and, in particular, to how it differs between the sexes - I can tell you that in my academic circles these IQ figures are barely disputed.
Ever since the Frenchman Alfred Binet devised the first intelligence test in 1905, study after study has confirmed the same result. When it comes to IQ, men and women - at least once they've gained adulthood - simply are not equal.
Boys and girls may start out with the same IQ but by 16 or so boys are starting to inch ahead. The ever-growing success of girls at GCSE, A-level and now at university would seem to refute this - but the blame lies with our exam system, with its emphasis on coursework, which rewards diligence more than it does intelligence.
The undeniable, easily measurable fact remains that, by the time both sexes reach 21, men, on average, score five IQ points higher than women.
Before discussing how and why this might be, I ought to explain what psychologists mean by intelligence. It's made up of a range of cognitive abilities that include reasoning, problem-solving, spatial ability, general knowledge and memory.
In all of these, men outperform women - although women hold their own when it comes to verbal reasoning and have a definite edge in foreign language skills and spelling.
We must look to the field of evolutionary psychology for an explanation of why men have emerged as the more intelligent sex.
As the hunter part of a hunter-gatherer society, men were faced with complex, life-threatening problems that needed solving on a daily basis. For example, how to kill that elusive deer?
The hunters that used all their mental capabilities to come up with the answers, successfully killing animals day after day, were clearly the most intelligent.
They were the high-status males of their day and - provocative as it is to say so - must have possessed far sharper minds than those of women engaged in the relatively simple tasks of gathering berries and raising children.
The difference in intelligence between boys and girls starts to emerge at school
The difference in intelligence between boys and girls starts to emerge at school
These high-status males would also have been the most eligible mates, and it would be their genes - chief among which would be those controlling male brain size - that would be passed on to the next generation.
The result is that men today still have physically bigger brains than women, even after adjustments for their different-body size. Might this underpin the five-point difference in IQ between the sexes?
Of course, in normal daily life, there's not much real difference between a man with an IQ of 105 and a woman with an IQ of
100. The real difference only emerges as we rise up the IQ scale to the sort of level that the really top jobs require and as we drop lower down the scale - because men, as it turns out, have a much wider range of intelligence than women.
As a result, there are not only far more men with high IQs than there are women, but there are also, as I'm sure any woman would tell you, far more stupid men around than there are stupid women.
There is, as yet, no simple or, indeed, totally convincing explanation as to why this is, but while the abundance of stupid men has always caused social problems, it is the relative abundance of highly intelligent men that has caused problems for several generations of emancipated, liberated, ambitious women.
As a result, when these women get close to the top, they are simply out-numbered by highly intelligent and often ruthlessly ambitious men.
As our hunter-gatherer example has already suggested, men and women have also evolved different kinds of intelligence.
The demands of hunting - devising tactics and strategies, anticipating likely outcomes - favoured the development of reasoning, together with mathematical and spatial abilities, which is why, thousands of years later, men continue to be overrepresented in fields such as maths and physics.
However, when it comes to verbal intelligence, women match men because, in our hunter-gatherer past, women needed verbal abilities to negotiate their relationships with both men and women and to teach and socialise their children.
This explains why they are every bit as successful as men at writing novels, say, or even newspaper columns. Their superior foreign language skills explain why if you walk into a university language lecture theatre, you won't find many men.
But there's another reason why, at the very highest and most demanding of levels in society, men have a natural advantage - and it's one we've seen in countless natural history TV documentaries.
Take, for example, the case of rutting stags or fighting chimps and you get the generally aggressive idea. Thanks to high levels of the male sex hormone testosterone, men are far more competitive and motivated for success than women.
For a man - at least as far as his hormone system is concerned - succeeding, competing and beating his rivals is very much still a matter of life and death.
Consequently, ambitious, high-achieving men typically work harder, compete more aggressively and become totally immersed in their careers, while even the most high-achieving women will often admit to finding themselves distracted by their genetically preconditioned aptitude for nurture and support.
For them, it is often a question of what to get for supper, or whether the children have got clean shirts for school. These are small distractions, admittedly, but at the very highest level they have an effect.
As an academic, it's my job to tell the truth, to explain the scientific evidence before us, irrespective of how unfashionable my conclusions are.
Big ideas such as Galileo's theory that Earth revolved around the Sun, rather than vice versa, or Darwin's theory of evolution, met with vociferous opposition when first advanced.
And, certainly, the ideas I've laid out here have already got some highly respected people into very serious trouble.
Lawrence Summers
Economist Lawrence Summers was forced to resign after saying men are better than women at certain jobs
In 2005, the distinguished economist Lawrence Summers was forced to resign as President of Harvard University after expressing the view, at a seminar on diversity in the academic workplace, that in some fields the innate cognitive differences between the sexes might make the search for a perfect 50:50 gender balance impossible.
He didn't accept that the lack of women at senior level was all due to glass ceilings, anti-social hours or lack of opportunity and encouragement.
Instead, he went with what the science is clearly telling us - that at the really top level in maths and science, when we're not dealing with average intelligence but near genius, there are simply more men around who can do the job.
For that simple statement of truth, he was eventually forced out of his post.I take some comfort from the fact that Lawrence Summers' hormonally-driven male competitive instincts kicked in and he has now bounced back to become a senior economic adviser to President Obama.
But what if he and I are right - as I am 100 per cent convinced we are? If men are innately better at certain subjects than women, then why should society struggle so hard - and so expensively - to try to engineer a perfect balance between the sexes?
By all means, take steps to ensure that boys and girls get the same opportunities in education, but let's also accept that those same opportunities will not produce the same outcomes. Men will always outnumber women in certain fields and vice versa.
My argument isn't based on crude chauvinist doctrine (although I'm quite sure my opponents will disagree) but on decades of research, relatively simple statistics and an understanding of the law of averages.
Of course, just because men, on average, are more intelligent then women, doesn't mean there are no individually brilliant women around.
If I'm right, it doesn't mean there will be no female professors of physics; it just means we should accept that there will be fewer of them. Nor does it mean that a woman will never win the Fields Medal for mathematics; it just means that we live in a world where such an event is very, very unlikely.
I realise my views are unfashionable, just as I realise the juggernaut of sexual equality and political correctness will take an awful lot of stopping.
But I say to the social engineers who dream up ever-more-ingenious ways of getting more women into top positions; don't be surprised if you find your nobly motivated ambitions foundering on the immovable rock of human nature.
• Professor Richard Lynn is Professor Emeritus of Psychology at the University of Ulster.