Wealth is less to do with hard work or luck and more to do with your genes, DNA study shows

The findings below were well-known from twin studies but our knowledge of genetics has now advanced to the stage where we can look for the actual genes which underlie those findings.  And we are now begining to see them.  We can see that the genes that lead to high intelligence also lead to higher income etc.  In their usual blind way, Leftists usually dispute that IQ tests really measure anything.  But when you are seeing the associations in actual human genes, there is much less room for dispute.  The full, very detailed paper underlying the report below is here

It should be noted that the same studies which show a strong IQ influence on income also show negligible effects from family environment and other environmental variables.  Your genes really are your destiny and there's not much you can do about it. That finding will put a lot of noses out of joint on both the Right and the Left but that is what the data shows


Wealth and success may be less to do with hard work or luck and more to do with DNA, it seems. An analysis of 286,000 Britons showed that the genetic make-up of those who earned over œ100,000 differed from those on low incomes.

A scan pointed to 24 `golden genes' that affect intelligence, the immune system, and the strength of muscles and heart - and so can make the difference between economic success and poverty.

The discovery follows work at the Centre For Cognitive Ageing in Edinburgh.

Three-quarters of the genes are linked to intelligence, the scientists found. But physical attributes also affect the chances of being wealthy and some of these may be inherited.

`Genetic variants associated with higher income correlate with a genetic predisposition for greater intelligence, a longer lifespan, better physical and mental health, fewer feelings of tiredness, having fewer children and better living conditions,' the researchers say in a paper which is yet to be published.

SOURCE 

Slow vocab growth associated with hyperactivity in kids

The relevant academic journal article is Vocabulary development and trajectories of inattention-hyperactivity and emotional symptoms via academic ability and peer problems" by Elizabeth Westrupp et al.

It's a very painstaking piece of research but is greatly impoverished theoretically.  They don't seem to have realized that all they did was to rediscover IQ.  Yes, that pesky IQ again that no respectable academic may mention these days. Low IQ is of course associated with slow language development and all sorts of health and behavioral problems in later life. The prisons are full of low IQ people.  So Elizabeth and her friends have just reinvented the wheel.  Sad

Political correctness is a plague on all research concerning human beings.  So much effort has been put into research that is inconclusive due to the failure to account for IQ differences. If IQ WERE controlled for, most of the brightly-reported "findings" would lapse into statistical non-significance or negligible significance

In science, political correctness is a great evil.  It is a relentless enemy of truth


Children whose vocabulary skills develop slowly are more likely to experience emotional and behavioural issues in adolescence, according to a new Deakin University study, published today in the journal Child Development.

The research, led by Deakin School of Psychology researcher Dr Elizabeth Westrupp, was the first to model how children's language development influences changes in mental health problems over a 10 year period, from early childhood to adolescence.

"We found new evidence that lower growth in vocabulary over primary school was associated with increased child hyperactivity-inattention at eight to nine years, and more rapid increases in hyperactivity-inattention over early to middle teenage years, up to 14 to 15 years," Dr Westrupp said.

"These findings show the importance of monitoring children through middle childhood and adolescence as they develop."

As part of the study, data was gathered from almost 5000 Australian children, with children assessed six times between four and 15 years of age.

Dr Westrupp said the study also investigated possible reasons for the association between language development and behavioural issues.

"We found that children's academic experiences in middle childhood explained the link between early vocabulary development and teenage emotional and behavioural problems," she said.

"It may be that children with lower vocabulary skills struggle more in the classroom with reading and literacy, which then leads to the development of behavioural and emotional problems in teenage years."

Dr Westrupp said early literacy-based interventions may alleviate declining academic, emotional and behavioural functioning in adolescence.

"There's already some evidence to suggest that children with early language problems have higher rates of behavioural and emotional difficulties compared to other children," Dr Westrupp said.

"However prior research only looked at children at one point in time, and we know that children's language ability and mental health are not static, they change as children grow.

"Understanding these associations will allow parents and teachers to better support children in preventing childhood mental health problems."

Dr Westrupp said it was critical the focus was not just on kids who entered school with low language skills, but also kids who were dropping behind their peers in the first few years of primary school.

"We need to be aware that they are also at risk. Schools and parents must work together to identify and monitor children falling behind in language, that means having supportive and regular conversations about how a child's language is developing," she said.

"It also means oral language based interventions in the classroom may be important beyond just the first few years of primary school, and incorporating specialist oral language skills and interventions into the standard curriculum could be beneficial. So that's working with children around the meaning of words, the structure of words, and using words in new contexts.

"There is some explicit language teaching in the first years of formal schooling, but there's much less focus in older years. So a continued emphasis on these skills would help us to best support children to thrive."

Media release by email from Elise Snashall-Woodhams -- e.snashallwoodhams@mediaunit.deakin.edu.au

All babies are born equal, no matter their race or class (?)

Do-gooder BS gets really extreme here.  What they did was equalize the mothers in major ways and then discovered that their babies were equal too!  If a student had handed me a research proposal as dumb as that, I would have failed it.  IQ, health and much else is inherited and IQ is quite well related to physical health, wealth, social position etc. So the equalizations they did would have strongly equalized IQ as well

But that's not the worst of it. They examined IQ only up to age 2.  That is also hilarious.  You cannot reliably measure IQ at age 2.  Any scores you get at that age have little or no relation to scores at ages 16 or 30 (for instance)

What a shemozzle!  Totally unwarranted inferences from a brainless study

Babies born in similar circumstances will thrive regardless of race or -geography, Oxford-led research has found, quashing the idea that race or class determines intelligence.

In a scientific first, the team of -researchers tracked the physical and intellectual development of babies around the world from the earliest days after conception to age two.

"At every single stage we've shown that healthy mothers have healthy -babies and that healthy babies all grow at exactly the same rate," said Prof -Stephen Kennedy, the co-director of the Oxford Maternal and Perinatal Health Institute.

"It doesn't matter where you are living, it doesn't matter what the colour of your skin is, it doesn't matter what your race and -ethnicity is, receiving decent medical care and nutrition is the key."

The INTERGROWTH-21st Project, led jointly by Prof Kennedy and Prof Jos‚ Villar at Oxford, involved nearly 60,000 mothers and babies, tracking growth in the womb, then followed more than 1,300 of the children, measuring growth and development.

The mothers - in locations as diverse as Brazil, India and Italy - were chosen because they were in good health and lived in similar, clean, urban environments. Their babies scored similarly on both physical and intellectual development.

The study should help settle the debate over the role of genetics in determining intelligence, which has been rumbling since the publication of Charles Murray's The Bell Curve in the Nineties. The book argued that a "cognitive elite" was becoming separated from the general population.

"There's still a substantial body of opinion out there in both the scientific and lay communities who genuinely believe that intelligence is predominantly determined by genes and the environment that you're living in and that your parents and grandparents were living in and their nutritional and health status are not relevant," said Prof Kennedy. "Well, that's clearly not the case."

SOURCE  

UK: Education is NOT the great leveller

This is a fairly iconoclastic article.  That the author is of Hungarian origin may explain that. She is able to take an outside view.

But she is of course right -- though she doesn't really spell out why.  Social class continua are heavily correlated with IQ -- which is genetically inherited -- and education can do nothing to increase IQ.  Rich people are mostly smarter and have mostly smarter kids.  So their kids inherit their class position both socially and genetically. There are of course exceptions but most people end up in a social position matched to their IQ. Smart kids do at times emerge from poor backgrounds and provisiion to advance them is well warranted.  Grammar schools do that.

The push for more and more education for everyone, however,  is fundamentally misguided.  The years out of the workforce impoverish the country, if anything

Britain is unusual in having what could be seen as two status hierarchies -- a wealth hierarchy and a nobility hierarchy. Some members of the nobility (titled hereditary aristocracy) can even be poor.  But the two have a long history of melding into one another.  Poor aristocratic males -- and some not so poor -- have a historic habit of marrying rich American heiresses, for instance.  Winston Churchill was one of the results of such a union.  The American family buys prestige and the British family has its fortunes refreshed.  And as the progeny of often self-made men, the ladies concerned will be bright.

More broadly, noble titles are still much valued and respected in Britain so an aristocratic male will have a wide choice of potential partners.  He is able in fact to get a woman with it all -- brains and beauty.  And so it often happens.  So there has long been a steady influx of brains into the nobility -- so even in Britain, prestigious persons generally tend to be bright


For two decades, social mobility has been a central concern in British politics. Increasing equality of opportunity, in the context of rising inequalities between people's lives, has been a shared goal across the party political spectrum. Politicians have also agreed that educational policy is crucial to achieving this goal. This has made the thrust of speeches on social mobility given over the years by politicians including Tony Blair, Gordon Brown, David Cameron, Nick Clegg and Theresa May interchangeable.

Yet, new research I've published with my colleague John Goldthorpe, which brings together results from extensive British birth cohort studies, points to a serious disconnect between the discussion of social mobility in political and policy circles and the findings of sociological research.

In our analysis, we treat social mobility in terms of social class, and make a clear distinction between absolute and relative mobility rates. Absolute rates simply refer to the proportions of individuals who have moved to different class positions to those of their parents, whether in an upward or downward direction. Relative rates compare the chances of individuals from different class origins ending up in a different class "destination".

Contrary to what has become widely claimed in the media, mainly as a result of - often misunderstood - research by economists, social mobility in Britain is not in decline.

Absolute rates of class mobility between generations have been stable at least over the period since World War II. Men and women today are just as likely to be found in different class positions to those of their parents as they were in the 1950s.

The important change is, however, that rates of upward mobility are falling and rates of downward mobility are rising, as our research and the graph above shows. In this sense, young people now face less favourable mobility prospects than their parents or grandparents did. This is the result of the slowdown in the steady growth of managerial and professional employment that drove increasing upward mobility in the "golden age" from the 1950s up to the 1980s.

Relative rates of social mobility are also essentially stable: the inherent "stickiness" between the class positions of parents and children has altered little over at least the last half century. And in the case of "long-range" mobility - between, say, the lower stratum of the working class and those in managerial and professional jobs - quite extreme inequalities in relative chances exist.

Our findings show that the children of parents in higher managerial and professional positions are 20 times more likely to end up in such positions, rather than in working class positions, than children of working class parents are.

Not a low mobility society

Education plays an important role in determining whether a person is class mobile or immobile. But it does not follow that more education means more mobility at a societal level. For education to promote mobility at a societal level, the association between a person's class origins and their educational attainment must weaken, while the association between their educational attainment and their class destinations must strengthen. But as our research shows, neither of these changes is in fact apparent. And that's especially the case if education is considered in relative terms: for example if account is taken of the fact that a degree is worth far more in the labour market if only 10% of a birth cohort have one than if 40% do.

Again, contrary to what is widely claimed in the reports such as those by the Social Mobility Commission, Britain is not a distinctively low mobility society. Across European countries, rates of absolute class mobility are very similar. And as regards relative rates, Britain is one of a group of West-Nordic countries that show - comparatively - high fluidity within their class structures.

One reason for this is that, in Britain, education is not class destiny to the same extent as it is in a country such as Germany. In Germany, and several other Western-Central European countries, the educational system is highly stratified, with early selection for different types of school. Because there is then a tight link between formal educational qualifications and employment opportunities, educational inequalities are rather systematically translated into labour market inequalities. Where such "credentialism" prevails, education can in fact prove a barrier to, as much as a source of, social mobility.

No great leveller

Education is not "the great leveller" that can break the link between inequality in the conditions under which people live and inequality of opportunity. Parents with superior resources - economic, as well as social and cultural ones - will use their resources as necessary to give their children a competitive edge. Those wealthy enough can resort to the private sector, but for others the "commercialisation of opportunity" occurs by buying houses in the catchment areas of high-performing state schools, engaging private tutors for their children, and providing them with extensive out-of-school activities and experiences designed to improve their academic performance.

In addition, further education, or lifelong learning, turns out to promote immobility rather than mobility. As my research shows, it mainly gives "second chances" to those from more advantaged backgrounds whose performance in mainstream education gave them insufficient assurance that they would be able to maintain their parents' position. It primarily serves to prevent downward mobility.

So far as absolute mobility is concerned, the most effective way of increasing upward mobility would be through economic and social policies that could renew the expansion of managerial and professional employment, so as to bring back the conditions of the golden age. One way of equalising relative rates of social mobility would be for employers to develop internal promotion and training policies to take full advantage of the educationally "wasted talent" that exists among their workforces and to remove requirements for formal qualifications of an irrelevant kind.

But in all societies with a capitalist market economy, a conjugal family system and liberal-democratic policies, a limit may exist on the extent that mobility chances can be equalised. As this limit is approached, policies aimed at further equalisation will become increasingly contested, and social mobility will cease to be a matter on which political consensus prevails.

SOURCE 

What you are born with matters a lot more than your education

It's true and has long been known but is a bit surprising coming from UCSD.  They avoided mentioning that what they were studying was IQ, however

Summary:

Youthful cognitive ability strongly predicts mental capacity later in life.

Early adult general cognitive ability [IQ] is a stronger predictor of cognitive function and reserve later in life than other factors, such as higher education, occupational complexity or engaging in late-life intellectual activities.
    
FULL STORY

Early adult general cognitive ability (GCA) -- the diverse set of skills involved in thinking, such as reasoning, memory and perception -- is a stronger predictor of cognitive function and reserve later in life than other factors, such as higher education, occupational complexity or engaging in late-life intellectual activities, report researchers in a new study publishing January 21 in PNAS.

Higher education and late-life intellectual activities, such as doing puzzles, reading or socializing, have all been associated with reduced risk of dementia and sustained or improved cognitive reserve. Cognitive reserve is the brain's ability to improvise and find alternate ways of getting a job done and may help people compensate for other changes associated with aging.

An international team of scientists, led by scientists at University of California San Diego School of Medicine, sought to address a "chicken or egg" conundrum posed by these associations. Does being in a more complex job help maintain cognitive abilities, for example, or do people with greater cognitive abilities tend to be in more complex occupations?

The researchers evaluated more than 1,000 men participating in the Vietnam Era Twin Study of Aging. Although all were veterans, nearly 80 percent of the participants reported no combat experience. All of the men, now in their mid-50s to mid-60s, took the Armed Forces Qualification Test at an average age of 20. The test is a measure GCA. As part of the study, researchers assessed participants' performance in late midlife, using the same GCA measure, plus assessments in seven cognitive domains, such as memory, abstract reasoning and verbal fluency.

They found that GCA at age 20 accounted for 40 percent of the variance in the same measure at age 62, and approximately 10 percent of the variance in each of the seven cognitive domains. After accounting for GCA at age 20, the authors concluded, other factors had little effect. For example, lifetime education, complexity of job and engagement in intellectual activities each accounted for less than 1 percent of variance at average age 62.

"The findings suggest that the impact of education, occupational complexity and engagement in cognitive activities on later life cognitive function likely reflects reverse causation," said first author William S. Kremen, PhD, professor in the Department of Psychiatry at UC San Diego School of Medicine. "In other words, they are largely downstream effects of young adult intellectual capacity."

In support of that idea, researchers found that age 20 GCA, but not education, correlated with the surface area of the cerebral cortex at age 62. The cerebral cortex is the thin, outer region of the brain (gray matter) responsible for thinking, perceiving, producing and understanding language.

The authors emphasized that education is clearly of great value and can enhance a person's overall cognitive ability and life outcomes. Comparing their findings with other research, they speculated that the role of education in increasing GCA takes place primarily during childhood and adolescence when there is still substantial brain development.

However, they said that by early adulthood, education's effect on GCA appears to level off, though it continues to produce other beneficial effects, such as broadening knowledge and expertise.

Kremen said remaining cognitively active in later life is beneficial, but "our findings suggest we should look at this from a lifespan perspective. Enhancing cognitive reserve and reducing later life cognitive decline may really need to begin with more access to quality childhood and adolescent education."

The researchers said additional investigations would be needed to fully confirm their inferences, such as a single study with cognitive testing at different times throughout childhood and adolescence.

SOURCE 

Australian psychologists are down on "Traditional Masculinity" too

The most substantial piece of evidence from Australia for the criticisms is the "Man Box" study mentioned below.  It is a colourfully presented "report", not a refereed academic journal article.  And that shows.  It is not as bad as some such reports in that some care was taken with the sampling and conventional statistical significance was observed but it is basically crap.  Let me say in detail why:

For a start, no factor analysis of the questions asked is offered.  So is there in fact such a thing as a "man box"?  We do not know.  A strong first eigenvector would have reassured us but we are not told of one.  I once did a survey of allegedly female attitudes (The BSRI) which found the attitudes concerned not to be characteristic of Australian females.  They were not sex-polarized at all. So are we sure that the man box attitudes are in fact characteristic of Australian male attitudes?  We cannot assume it. Were there similar attitudes among women?

And including the man box questions within a larger survey was not done.  Doing so might have revealed that the questions had a larger identity.  For instance, many of the questions seem to me to be rather like assertiveness questions, and assertiveness is usually praised.  There certainly should have been some attempt to distinguish the "bad" man box questions from assertiveness.   Could some man box attitudes be good?

And the selection of man box attitudes was also tendentious.  Traditional male attitudes do for instance include courtesy towards women.  To this day I hold car doors open for women but that is only a trivial thing.  There is also a strong traditional male inhibition against hitting women, for instance.  Feminists are much concerned about domestic violence so should they encourage traditional male attitudes of courtesy and restraint towards women?  Nothing like that was examined in the survey, funnily enough.

And what about the traditional male attitude that self-sacrifice is noble?  What about the times when men have sacrificed themselves to save women -- in an emergency situation such as a sinking ship?  Is that noble or foolish?  Sane women would hope it is noble but there is no mention of such nobility in the man box.  The whole conception of the man box is thoroughly bigoted from the get-go.

But the most deplorable omission in the research is a complete failure to apply any demographic controls.  They apparently had demographic data but did not use it to segment their sample.  One does wonder why.  Were the results of such segmentation too embarrassing?  Were man box attitudes almost exclusively working class for instance?  From my own extensive background in survey research, I suspect it.  I always looked at demographic correlates of the attitudes I examined and social class variables were often significant.

And one social class variable that they would have avoided studying at all costs is the dreaded IQ.  Yet IQ is powerfully correlated with an amazing array of other variables.  In this case it could even explain some male/female differences. Why, for instance, do men on average die earlier than women?  The research below says it is because of their bad male attitudes but there is another explanation. Male IQ is more variable than female IQ.  There are more brilliant males but also more spectacularly dumb males.  And, for various reasons, IQ is significantly correlated with health.  So it is likely that most of the males who die young were simply dumb.  They did more silly and dangerous things, for instance.

All in all the report is just a piece of feminist propaganda designed to fool the general public.  I am guessing that they had no expectation that it might come under the scrutiny of an experienced survey researcher


Traditional masculinity has been labelled "harmful" in a major move by a health body, linked with high rates of suicide and violence.

The American Psychological Association released a report last week, citing more than 40 years of research on the issue of "masculine ideology" - a step praised by Australian experts.

"Traditional masculinity ideology has been shown to limit males' psychological development, constrain their behaviour, result in gender role strain and gender role conflict and negatively influence mental health and physical health," it said.

Increasingly referred to as "toxic masculinity", traditional ideals surrounding manhood are usually toughness, aggression, a suppression of emotion, dominance and stoicism.

Queensland University of Technology sociologist Michael Flood said some of the ways boys are raised can have "significant costs" for the community.

Across the country today, an estimated six men will take their own lives - three times the number of women to die by suicide.

"There's growing recognition that norms of masculinity in many ways are limiting for men themselves," Dr Flood told news.com.au.

"Going along with traditional masculine beliefs increases the risk of suicide - there have been studies to indicate that. If you think being a man means not asking for help or not showing pain, being a John Wayne character and going it alone, you can't cope when things are hard."

Traditional masculinity has a place in a number of scenarios, Dr Flood said, where a number of those qualities can be very useful. "Being tough and stoic are exactly the qualities you need if you're fighting a fire or something like that, but once it's over, you need other qualities," he said.

"Some of those men (without) are poorer at some of the qualities that many people recognise are important in contemporary relationships - communication, emotional expression."

There's growing recognition in the fields of men's mental health, education and the prevention of violence against women and children that "the norms of masculinity" can be harmful.

"Unless we tackle this, we'll continue to see large numbers of men turning up in hospitals, being assaulted, committing suicide, and suffering in silence and so on," Dr Flood said.

Criticisms from some segments of the community that the discussion about toxic masculinity is an attack on men are unfounded, he said.

"We need to distinguish between men and masculinity. The attack on the narrow messaging is not an attack on men. This is driven by a concern for men."

Dr Flood was involved in the groundbreaking Man Box study last year, which found that young Australian men who oversubscribe to traditional notion of masculinity had poorer health and wellbeing outcomes.

"We also found that many of them have poorer relationships with others and were more likely to be involved in violence," he said.

Of those surveyed - a cohort of 1000 men aged 18 to 30 - 69 per cent felt society expected them to act strong and 56 per cent felt being a man meant never saying no to sex.

Another 36 per cent agreed that society pressures them to shun friendships with gay men and 38 per cent thought boys shouldn't learn how to cook and clean.

SOURCE 

Are our life chances determined by our DNA?

In less than two decades, the bid to read the human genome has shrunk from billion-dollar space-race project to cheap parlour game. In 2000, President Bill Clinton and Tony Blair, then UK prime minister, jointly announced that scientists had elucidated the three billion letters of the human genome — or discovered “the language in which God created life”, as the US president solemnly phrased it.

In 2018, prompted by opposition goading, the Democrat US senator Elizabeth Warren took a consumer DNA test to prove a strain of Cherokee ancestry. Flashing a sliver of exotic bloodline for political advantage turned out to be a calamitous misjudgment: her actions upset Native Americans, who regard identity and culture as more than a matter of DNA.

Science too is engaged in the same enterprise: to reduce the complexity of human identity to genetics. While we have long known that genes build our bodies — determining eye and hair colour, influencing height and body shape — there is a growing conviction that genes also sculpt the mind. As the cost of gene-sequencing technology has plunged to a few hundred dollars, millions of people have had their DNA sliced and diced by scientists seeking to quantify the genetic contribution to personality, intelligence, behaviour and mental illness.

This is the dark and difficult territory explored by three important books that embody a new zeitgeist of genetic determinism. If DNA builds the brain and mind — the puppetmasters pulling our behavioural strings — then selfhood becomes circumscribed largely by our genes. The idea that we are little more than machines driven by our biology raises a profound conundrum: if the genes we inherit at conception shape personality, behaviour, mental health and intellectual achievement, where is the space for society and social policy — even parents — to make a difference? What of free will?

As might be guessed from its klaxon of a title, Blueprint is unequivocal in stating the supremacy of the genome. “Genetics is the most important factor shaping who we are,” opens Robert Plomin, a behavioural geneticist at King’s College London recognised globally (and reviled by some) for his research into the genetics of intelligence. “It explains more of the psychological differences between us than everything else put together,” he writes, adding that “the most important environmental factors, such as our families and schools, account for less than 5 per cent of the differences between us in our mental health or how well we did at school.”

For decades, Professor Plomin has been using twin and adoption studies to tease out the relative effects of genes and environment. Identical twins share 100 per cent of their DNA; in non-identical twins this drops to 50 per cent (the same genetic overlap as regular siblings). Adopted children share a home environment, but no DNA, with their adoptive parents; and 50 per cent of their DNA, but no home environment, with each of their biological parents.

A careful study of these permutations can point to the “heritability” of various characteristics and psychological traits. Body weight, for example, shows a heritability of about 70 per cent: thus 70 per cent of the differences in weight between people can be attributed to differences in their DNA. Identical twins tend to be more similar than non-identical, fraternal twins; adopted children are more like their biological parents than their adoptive parents.

Breast cancer, widely thought of as a genetic disease, shows a heritability of only 10 per cent. In contrast, it is 50 per cent for schizophrenia; 50 per cent for general intelligence (reasoning); and 60 per cent for school achievement. Last year Plomin claimed that children with high “polygenic scores” for educational achievement — showing a constellation of genetic variants known to be associated with academic success — gained good GCSE grades regardless of whether they went to non-selective or selective schools. His conclusion was that genes matter pretty much above all else when it comes to exam grades.

Even the home, the very definition of “environment”, is subject to genetic influence, he says. If kids in book-filled homes exhibit high IQs, it is because high-IQ parents tend to create book-filled homes. The parents are passing on their intelligence to their children via their genes, not their libraries: “The shocking and profound revelation . . . is that parents have little systematic effect on their children’s outcomes, beyond the blueprint that their genes provide.” His conclusion is that “parents matter, but they don’t make a difference”.

That is not the only seemingly contradictory message. Plomin describes DNA as a “fortune-teller” while simultaneously emphasising that “genetics describes what is — it does not predict what could be”. This caveat is odd, given his later enthusiasm for using genetic testing predictively in almost every aspect of life: in health, education, choosing a job and even attracting a spouse. He suggests, for example, that we could use polygenic scores for schizophrenia “to identify problems on the basis of causes rather than symptoms”.

This vision sounds worryingly like pre-medicalisation. Plomin proclaims himself a cheerleader for such implications but is disappointingly light on the ethical issues. A predisposition might never manifest as a symptom — and besides, “possible schizophrenic” is not the kind of descriptor I would want to carry around from birth.

Plomin admits that cowardice stopped him writing such a book before now; it probably also stopped him from addressing alleged racial differences in intelligence. This is a grave omission, as he is one of the few academics capable of authoritatively quashing the notion. James Watson, the 90-year-old DNA pioneer, recently restated his belief that blacks are cognitively inferior to whites. Those, like Plomin, responsible for fuelling the resurgence in genetic determinism have a responsibility to speak out — and early — against those who misuse science to sow division. (Plomin is writing an afterword for future editions.)

Neuroscientist Kevin Mitchell believes that genes conspire with a hidden factor — brain development — to shape psychology and behaviour. Neural development, he contends persuasively in his book Innate, adds random variation to the unfurling of the genetic blueprint, ensuring individuality, even among identical twins. These special siblings, though clones, rarely score identically for psychological traits. Genes are the ingredients but a lot depends on the oven: “You can’t bake the same cake twice.”

Mitchell, associate professor of neuroscience at Trinity College Dublin, explains: “It is mainly genetic variation affecting brain development that underlies innate differences in psychological traits. We are different from each other in large part because of the way our brains get wired before we are born.” Genetic relatives have brains that are wired alike. Thus, we should look to the cranium, not only to chromosomes, to learn how minds are shaped.

Indeed, each of us is a miniature study in how a genetic blueprint can quiver under the influence of random variation, like a pencil tracing that does not conform exactly to the original outline. The genes directing the development of each side of your body are identical — but you are still slightly asymmetrical (put a mirror down the middle of a mugshot and see how weird you look with perfect symmetry). Fascinatingly, identical twins do not always show the same handedness, despite shared DNA and upbringing.

What goes on in that oven, or the brain, cannot be described as environmental — the catch-all term for non-genetic factors — because it is intrinsic to the individual rather than shared. Mitchell labels it the “non-shared environment”, a crucial but overlooked component of innate traits. Once this factor is folded in, “many traits are even more innate than heritability estimates alone would suggest”.

This, he insists, does not close the door to free will and autonomy. Genes plus neural development pre-programme a path of possible action, not the action itself: “We still have free will, just not in the sense that we can choose to do any old random thing at any moment . . . when we do make deliberative decisions, it is between a limited set of options that our brain suggests.” Having free will, he adds, does not mean doing things for no reason, but “doing them for your reasons.” Those include wanting to conform to social and familial norms; unlike Plomin, Mitchell recognises the reality that societies and families can and do make a difference.

While both discuss heritable conditions such as autism and schizophrenia in terms of defective genes, Randolph Nesse turns this thinking on its head. In Good Reasons for Bad Feelings, he asks: why do such disorders persist in the human population, given that natural selection tends to weed out “bad” genes?

Mental illness and psychological ill-health, he theorises, could be the collateral damage caused by the selection, over evolutionary time, of thousands of genes for survival and fitness. Autism, for example, has a well-documented genetic overlap with higher cognitive ability: some biologists now regard autism as a disorder of high intelligence. Once, only the clever survived.

Nesse, who runs the Centre for Evolution and Medicine at Arizona State University, can also explain why life offers mental torment in abundance: “Natural selection does not give a fig about our happiness. In the calculus of evolution, only reproductive success matters.”

Charles Darwin was one of the first to see the similarity in facial expressions between humans and other animals: these hint at a shared evolutionary heritage when it comes to emotions. Jealousy and fear, for example, are thought to promote genetic survival: a jealous man who controls his partner is more likely to end up raising his own genetic offspring, according to the evolutionary scientist David Buss; fear makes us cautious and keeps us alive.

These are indeed good reasons for bad feelings. But extreme jealousy can lead to murder; extreme fear can become debilitating phobia. Panic attacks — an exceedingly common experience — mirror the fight-or-flight response. Anxiety, meanwhile, works on the smoke detector principle: “a useful response that often goes overboard”.

Nesse’s book offers fresh thinking in a field that has come to feel stagnant, even if new therapeutic avenues are not immediately obvious. The prevailing orthodoxy that each mental disorder must have its own distinct cause, possibly correctable through chemicals, has not been wholly successful over the decades. Biologists have also failed to uncover tidy genetic origins for heritable conditions such as schizophrenia and autism, instead finding the risk sprinkled across thousands of genes. Recasting our psychiatric and psychological shortcomings as the unintended sprawling by-products of evolution seems a useful way of understanding why our minds malfunction in the multiple, messy ways that they do. The UK’s Royal College of Psychiatry thinks so: it recently set up a special interest group on evolutionary psychiatry.

Given that natural selection is blind to organisms being happy, sad, manic or depressed, Nesse notes that things could have turned out worse: “Instead of being appalled at life’s suffering, we should be astounded and awed by the miracle of mental health for so many.”

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