October 2010 – Page 3

The unconscious expert

Expertise seems to work most effectively in the unconscious mind. An intriguing new study on predicting the outcome of football matches suggests that a period of unconscious thought, at least for experts, is most effective for accurately calling the result.

The research was led by Dutch psychologist Ap Dijksterhuis and involved asking hundreds of Dutch students to rate how much they knew about football and call the outcome of four matches from the football league in Holland.

In the first experiment, the participants were split into three groups, and after being given the matches to predict, were either asked to respond immediately, or were asked to give their answer after thinking about the outcomes for two minutes, or, alternatively, after completing a ‘2-back’ working memory task for two minutes – designed to keep the conscious mind occupied.

The initial results are a blow to sports pundits everywhere. Overall, expertise barely accounted for any ability to predict matches accurately. In fact, knowledge of football accounted for less than 2% of overall match calling success.

Nevertheless, when experts were compared to non-experts, the ability to strike home with a prediction was significantly improved by a period of non-conscious thought – that is, spending two minutes doing the ‘2-back’ task before answering.

The amount of success predicted by expertise was still low, just under 7%, but the power of expertise more than tripled.

In contrast, deliberately analysing the matches for two minutes or responding immediately made expert predictions worse. This is also evidence against the ‘blink effect’, popularised by writer Malcolm Gladwell, as instant responses were not a success.

The researchers also ran a second experiment on World Cup matches to better understand why the unconscious mind was doing so well. They additionally asked participants to guess the world ranking of each team – the biggest single predictor of match success in the tournament.

For immediate responders and conscious thinkers, the rankings they gave didn’t show much relation to the outcome of matches. Unconscious thinkers, on the other hand, showed a strong link between ranking and match outcome.

World ranking was the single most useful piece of information in guessing World Cup scores, but even when people had accurate rankings, they tended to discount this information when given time to consciously mull it over. Perhaps there were distracted by a star player being off-form, or tabloid revelation about the team, or superstitions about playing in the away strip.

It’s not that these don’t have an effect, but that the conscious mind can give them undue weight.

The idea is that the unconscious mind is ticking away in the background and working on the problem, and that this is more effective than giving a rushed answer or one where the conscious mind is given free reign to override what’s going on in the ‘back of our minds’ with potentially irrelevant detail.

Looking at the bigger picture, the researchers used a similar choice for picking match outcomes as the football pools – a popular lottery-style form of gambling where punters predict matches as a wins, losses, draws and so on.

On the individual level the absolute boost in accuracy is small, but over the long-term or in syndicates, punters could significantly raise their chances by relying on unconscious deliberation.

Although it’s probably worth saying that chances are likely raised from minuscule to tiny, so you’re unlikely to be cashing in big time.

Link to study abstract and DOI entry.

Ten minutes of consciousness

I have to admit, I’m a little bored with consciousness, and my heart slightly sinks when I see yet another piece that rehashes the same old arguments. However, I thoroughly enjoyed this refreshing Cristof Koch talk where he engagingly describes his own approach to the neural basis of conscious experience.

The talk is from a recent debate on consciousness that was covered by The Guardian and serves as a great introduction to some of the major issues in the field.

Despite a minor relapse of his Mac-affliction half way through (sufferers may note that there is now a maintenance treatment that can ease the path to full remission) the talk is ten well-spent minutes which might just re-ignite your interest in consciousness.

Link to video of consciousness talk at The Guardian.

2010-10-08 Spike activity

Quick links from the past week in mind and brain news:

New York Magazine has an excellent article on the psychology of why people confess to crimes they didn’t commit.

The ever-incisive Neuroskeptic covers a fascinating study on retaliation and cycles of violence in the Israeli-Palestinian conflict.

Technology Review covers the launch of a massive new ‘connectome‘ project to map the connections of the brain on a massive scale.

Is there any evidence for the “porn-addicted brain”? Neurocritic hits it out of the park, if you’ll excuse the expression, with a great critical piece.

The New York Times covers how antipsychotics became some of the biggest selling drugs on the planet on the back of dodgy marketing and illegal sales practices. The lawsuits are now raining down.

A new 3D film by Werner Herzog on what the Chauvet cave paintings tell us about the mind of the creators gets a great write-up on The Beautiful Brain.

The Philosopher’s Zone had a fantastic discussion on the ‘extended mind hypothesis’.

Some excellent coverage of the recent ‘genetics of ADHD’ study and why genes are not a good answer to the stigma of mental illness over at Bad Science.

The Times has an excellent piece on the hidden dangers of ‘black box research’ where high-level algorithms shape our view of the world without us understanding what they’re doing. The article is paywalled but the author, Aleks Krotoski, has put a full version online.

Best forensic psychology blog on the net, In the News, discusses a radical proposal to apply ad-hoc ethics to managing violent sexual offenders.

The Dana Foundation has an excellent piece on what makes some people more vulnerable to stress and trauma than others.

How to form a habit. A truly fascinating piece from the BPS Research Digest – “the average time to reach peak automaticity was 66 days”.

The Economist reports on a new device for paralysed patients that allows them to communicate by sniffing.

Christine O’Donnell says scientists have made “mice with fully functioning human brains”. Wiring the Brain sardonically investigates this blinding scientific insight.

Scientific American Mind has a great piece on how researchers are measuring the beating of the heart to understand the mind.

Remind me to read Dan Ariely’s blog more often, it’s bloody brilliant. In this post there’s a copy of one of Hitler’s voting papers with a behavioural economics style nudge.

The New Yorker asks what we can learn about the mind from studying procrastination.

The history of ADHD is covered in a fantastic piece by the Child’s Play blog which is just getting better and better.

American Scientist has an in-depth review of the ‘Invisible Gorilla’ book on change blindness which looks very good.

There’s some fantastic coverage of the high cannibidiol, low memory impact cannabis study over at the mighty Addiction Inbox.

CNN has a great interview with Michael J. Fox on life and Parkinson’s disease.

Is epigenetics the fashionable new all-purpose woolly scientific explanation? asks a great post on Gene Expression.

The New York Times has an article exploring how memory biases lead us to think that are failings were in the distant past while our successes were only recent.

Diffusion Spectrum Imaging brain scans are really beautiful.

New Scientist covers the discovery of tattoos on an ancient Peruvian mummy that seemed to have a healing purpose.

The recent story on ‘the pill is changing women’s brains’ story is made coherent by a great post on Neurotic Physiology. Hint: the menstrual cycle has a similar effect.

Time has a fantastic piece marking the 30th anniversary of a newspaper report about an 8-year-old heroin addict that won the Pullitzer Prize – and was subsequently revealed as a fake.

October 10th is World Mental Health Day. Providentia has the low down.

The Wall Street Journal has a fascinating piece on how women are more likely to be rewarded at work if they’re thin, men as they rise in weight up to the point of 207 pounds! NB: Correlation, causation etc etc.

The Arabic anaesthetic sponge

A 1997 letter to the British Medical Journal describes an innovative surgical anesthetic used by Arabs in the middle ages that involved placing a sponge soaked in opium, hashish and scopolamine over the patient’s face.

From the ingredients, the patient was probably aware of little, let alone any pain, and it appropriately features in the dreamy Middle Eastern classic, Arabian Nights.

Editor—Anthony John Carter’s review of sedative plants skipped several centuries and did not mention the “Arabic anaesthetic sponge.” Opium infusion was known to Arab clinicians throughout the middle ages and was used commonly to relieve pain associated with inflammation or procedures such as tooth extraction and reduction of fractures. Poppy seeds were used in oral perioperative analgesic syrups or paste; their boiled solution was often used for inhalation.

Anaesthesia by inhalation was mentioned in R Burton’s Arabian Nights, and Theodoric of Bologna (1206-98), whose name is associated with the soporific sponge, got his information from Arabic sources. The sponge was steeped in aromatics and soporifics and dried; when required it was moistened and applied to lips and nostrils. The Arabic innovation was to immerse the “anaesthetic sponge” in a boiled solution made of water with hashish (from Arabic hasheesh), opium (from Arabic afiun), c-hyoscine (from Arabic cit al huscin) [aka scopolamine], and zo’an (Arabic for wheat infusion) acting as a carrier for active ingredients after water evaporation.

Link to full text of BMJ letter.

Dealing with delinquents in the 1920s

Canada’s The Daily Gleaner has a brief but revealing insight into the understanding of juvenile crime and delinquent behaviour in the 1920s.

Obviously the cultural standards of the day were different, so some behaviours considered ‘delinquent’ then were not be considered so now, and vice versa.

However, it is also clear from the piece that theories of how delinquency came about were influenced by very different sets of assumptions.

Prior to the emergence and expansion of psychiatry, moral and eugenic discourses dominated the understanding of juveniles and their treatment. However, Toronto Mayor Howland and other 19th-century reformers believed “allowing youth to go to the devil was a sheer waste.”

They believed there was no “such thing as a youth being really criminal at heart,” and that all deviant actions were just “surface depravity.”

Children were considered to be the product of their surroundings, and if a delinquent grew up in idleness and crime, that is what any child would be in a similar situation.

Previously, the dominant explanation for juvenile deviance was a ‘defective mind’ due to an inherited degenerate constitution. Famous at the time were life histories of degenerate families, with their poverty, prostitution, alcoholism and incest.

The brief article also mentions case reports of the time with a short excerpt which seems nothing short of jaw-dropping from a modern perspective:

Amanda, for example, had become “impudent of late” with a tendency to become “foxy and cunning.” Physical examination of her hymen showed she “had been immoral,” so she was found guilty of vagrancy and sent to the home for girls.

When Amanda was asked by a social worker about her life goals, she said she wanted to be an actress, and the psychiatrist was appalled. He suggested that a better occupation would be milliner, with release conditional on her acceptance.

Link to psychology and delinquency in the 1920s (via @jonmsutton).

Campaign man

Wired Science has an exclusive interview with Ari Ne’eman, the first openly autistic White House appointee in history, who has been given a place on the National Council on Disability that advises the president on equality for disabled people.

Ne’eman is an advocate of neurodiversity, which rather than automatically seeing conditions like autism and Asperger’s syndrome as diseases to be cured, understands them as another form of human variation that should be accepted.

As a society, our approach to autism is still primarily “How do we make autistic people behave more normally? How do we get them to increase eye contact and make small talk while suppressing hand-flapping and other stims?” The inventor of a well-known form of behavioral intervention for autism, Dr. Ivar Lovaas, who passed away recently, said that his goal was to make autistic kids indistinguishable from their peers. That goal has more to do with increasing the comfort of non-autistic people than with what autistic people really need.

Lovaas also experimented with trying to make what he called effeminate boys normal. It was a silly idea around homosexuality, and it’s a silly idea around autism. What if we asked instead, “How can we increase the quality of life for autistic people?” We wouldn’t lose anything by that paradigm shift. We’d still be searching for ways to help autistic people communicate, stop dangerous and self-injurious behaviors, and make it easier for autistic people to have friends.

But the current bias in treatment — which measures progress by how non-autistic a person looks — would be taken away. Instead of trying to make autistic people normal, society should be asking us what we need to be happy.

This issue is a particularly heated one, not least because describing someone as ‘on the autism spectrum’, or even ‘autistic’ tell us little about the individual.

People with a diagnosis of autism can range from highly intelligent but socially atypical individuals, to people who are unable to attend to their most basic needs and are severely cognitively impaired.

This diversity means that anyone seeming to champion autistic people is assumed by one party or other to be an interloper who doesn’t fully represent the range of life experiences, either of individuals or families with autistic members.

Ne’eman is certainly a powerful and articulate speaker and as the first autistic person to be appointed to an official advisory position, he will be seen as the ‘voice of autism’ whether he likes it or not.

Link to Wired Science interview with Ari Ne’eman.

Drone war psychology

As US military attacks by unmanned drone aircraft intensify, I was interested to find a podcast (mp3) on the psychology of combat drone piloting from Texas Tech University’s Psychology Podcast.

Unfortunately, their podcast series is not well indexed, but from what I can make out, the piece was from 2007 and interviews aviation psychologist Nancy Cooke and ex-fighter pilot and current drone interface designer Missy Cummings.

The discussion is notable for a couple of things. The first is the interesting point that although drones are aircraft, the designers are trying to stop engineers automatically designing control centres that look and work like aircraft cockpits.

Cockpits are designed to do the best job in the space allowed, and, although familiar, control systems for drones can be much better designed if the whole concept is divorced from the cockpit metaphor.

The second is that they don’t mention killing anyone.

I allowed myself a grim smile when Cummings is asked how the drones are used and she replies “search and rescue, for instance, downed hikers in remote areas, border patrols, we can use them to take pictures and that’s what happens a lot in Afghanistan and Iraq – they use predatory UAVs to really monitor a situation”.

The stress of being interviewed obviously caused ‘running an illegal air war in Pakistan’ to slip her mind.

Snarky comments aside, the psychology of killing remotely must play a huge role in how the drones are managed in combat, and it’s not as if the topic has never been broached.

‘On Killing’, a book on combat that analyses the role of psychological distance in kill decisions and their aftermath, is a classic in military psychology.

Nevertheless, the podcast is a brief but interesting interview on the psychology of drone flying and how the wider public feel about unmanned aircraft as they inevitably migrate from military weapons to civilian workhorses.

mp3 of interview on drone piloting psychology.
Link to Texas Tech podcast page.

The ’68 comeback perceptual

Elvis makes a fleeting comeback, accompanied by a milk drinking chimp and some well-dressed mice, in the hallucinations of a patient with Parkinson’s disease who is described in a case study published in the Southern Medical Journal.

He had compulsive gambling behavior and multiple hallucinations (visual and auditory). Visual hallucinations were simple (shapes of shadows, animal shapes like a raccoon, a cat, and a dog) and complex (a woman sitting next to him in car, two well-dressed little mice running around, a chimpanzee drinking his milk standing next to his lunch table in a restaurant, and Elvis Presley standing outside his door in his white coat and white trousers without a guitar). Once while fishing, he saw his dead uncle standing next to him and his uncle said, “It’s not going to work.” Auditory hallucinations were also both simple (incomprehensible sounds) and complex (like his uncle talking to him, nonspecific symphony, and constant melody of chimes). All hallucinations were associated with intact insight and were nonthreatening.

Although the patient was diagnosed with Parkinson’s, which is known to trigger hallucinations, it is likely they were caused as much by the dopamine-boosting medication than by the effects of the disease itself.

The patient was taking quite a selection, reportedly prescribed “a combined regimen including carbidopa/levodopa 25/100 mg four times a day (q.i.d.); carbidopa/levodopa 50/200 mg sustained release three times a day (t.i.d.) with a half tablet in the morning; entacapone 200 mg 5 times a day; pramipexole 1mg q.i.d. with 1.5 mg at bedtime (h.s.); amantadine 100 mg twice a day (b.i.d.); and clonazepam 1mg h.s.”

Despite the perceptual distortions encouraged by the meds, the patient is quoted as saying “It is the best control I have had of my motor functions in a long time” and refused to discontinue any of the treatments.

Link to PubMed entry for case study (via @anibalmastobiza).

Whacking off: a psychological history

The Insight Therapy blog has a fantastic dash through the psychological history of masturbation – looking at how self-pleasuring has been linked to everything from madness to blindness and has even inspired a type of biscuit [no, not that type].

Through the 19th century, the assault on “self-abuse” continued: Reverend Sylvester Graham invented the Graham crackers to curb sexual impulses. In the 1830s, Benjamin Rush, renowned physician and signer of the declaration of Independence, argued that masturbation caused tuberculosis, memory loss, and epilepsy. JH Kellogg, turn of the century medical writer and creator of breakfast cereal, believed signs of masturbation included acne, weak back, and convulsions. Noted 19th century physician and early sex research pioneer Richard von Krafft Ebing linked masturbation to homosexuality and other types of what he considered deviance and illnesses.

The piece makes the interesting point that that the practice is more common in men than women and has been linked to range of positive health outcomes, perhaps suggesting that we should be aiming to include masturbation in the drive to close the gender gap.

Link to Insight Therapy on ‘The Masturbation Gap’.

Edvard Munch in 100 words

This month’s British Journal of Psychiatry has the latest in their ‘100 words’ series on the Norwegian artist Edvard Munch, famous for his iconic painting ‘The Scream’ and his own struggles with mental illness.

The Norwegian Expressionist Edvard Munch caused outrage when his paintings were first shown in Berlin but became one of the most prolific artists of his time. Often described as having had bipolar affective disorder, his low moods and sense of isolation are evident in works such as The Scream, Separation,and Evening on Karl Johan. Yet the evidence of his diaries and his many biographies suggest more plausible diagnoses of depressive disorder and comorbid alcohol dependence. Art historians acknowledge his ability to represent extreme emotional states, while debating the extent to which Munch exploited the market for his ‘flawed personality’.

Link to DOI entry for article.

Distracted by the data

Wired has an incisive article looking at the science behind the ‘technology and multi-tasking are damaging the brain’ scare stories that regularly make the media.

The piece does a fantastic job of actually looking at specific studies on multi-tasking and distraction and questioning whether the ‘tech scare’ headlines are warranted given the findings.

The conclusion is neither that ‘all is well’ or that ‘we are all doomed’ but that we really have very little data – although none of it so far has given any credence to popular concerns that technology is impairing our intelligence.

The piece also hits on the crucial idea that talking of ‘technology’ or the ‘internet’ as a coherent whole is unhelpful because it has such different forms each with potentially different effects:

A solid consensus on digital multitasking is unlikely to be reached anytime soon, perhaps because the internet and technology are so broadly encompassing, and there are so many different ways we consume media. Psychological studies have seen a mix of results with different types of technology. For example, some data shows that gamers are better at absorbing and reacting to information than nongamers. In contrast, years of evidence suggest that television viewing has a negative impact on teenagers’ ability to concentrate. The question arises whether tech-savvy multitaskers could consume different types of media more than others and/or be affected in diffferent ways.

A research paper authored by a group of cognitive scientists titled “Children, Wired: For Better and for Worse” (pdf) sums it up best:

“One can no more ask, ‘How is technology affecting cognitive development?’ than one can ask, ‘How is food affecting physical development?’” the researchers wrote. “As with food, the effects of technology will depend critically on what type of technology is consumed, how much of it is consumed, and for how long it is consumed.”

There are some quotes from me included, but don’t let that put you off, as it remains a lively discussion of the science behind a common 21st century talking point.

Link to Wired piece on media, technology and brain studies.

The war changed me: brain injury after combat

The Washington Post has an amazing series of video reports on US soldiers who have returned from Iraq and Afghanistan with brain injury – often leading to a marked change in personality.

The reports cover veterans who have suffered numerous types of brain injury, from shrapnel-driven penetrating brain injuries to concussion-related mild-traumatic brain injury, and how they have adapted after returning home.

The treatments range from brain surgery to psychological rehabilitation and the interviews cover the difficulties from all angles – including the patients’, families’ and medical professionals’ perspectives.

It’s probably worth noting that this combat brain injury is not an area without controversy and the Washington Post piece follows the US military orthodoxy on mild traumatic brain injury – that all problems after blast concussion are due to brain damage.

Owing to the widespread use of improvised explosive devices many soldiers get caught up in a blast without suffering any visible physical injury, although they may suffer concussion due to the shock waves.

The US military is focused on the idea that subsequent problems – such as headaches, mood problems, trouble concentrating, irritability, impulsiveness or personality change – are due to the physical effects of the blast. This cluster of symptoms is often diagnosed as post-concussion syndrome or PCS.

Studies have found that, on average, soldiers who have experienced a blast are more likely to show changes in the micro-structure of the brain. However, not every soldier who shows the PCS symptom cluster has detectable brain changes or shows a clear link between the symptoms and the blast.

This latter point is important because the same symptoms can arise from combat stress – being caused by the emotional impact of war rather than a direct result of a shock to the brain.

It becomes clear why this distinction is crucial when you read the US military’s guidance on screening for mild traumatic brain injury which doesn’t have a specific way of distinguishing the effects of emotional stress from the effects of brain disturbance.

Owing to the fact that blasts are such common experiences for soldiers, this could lead to false positives where veterans are thought to have brain damage when they would be better off being treated for combat stress.

In fact, this exact same scenario was played out in World War I where ‘shell shock’ was originally considered to be caused by blast waves affecting the brain (hence the name) only for it to be later discovered that not everyone who had the symptoms had even been near a shell explosion.

Regardless of this medical debate, The Washington Post special report is a fantastic combination of real life experiences and the neuroscience of combat-related brain injuries. Highly recommended.

Link to WashPost ‘Coming home a different person’ with intro clip.
Link straight to main menu.

Rehabilitating the most vilified

ABC Radio National’s 360documentaries has a confronting edition that interviews two child sex offenders currently in treatment along with their psychologist, examining their offending behaviour, what led up to it and what they hope to change in their lives.

It’s neither morbid sensationalism nor an apology for crimes committed but there are plenty of moments that don’t make for easy listening.

It does, however, challenge lots of stereotypes about the sort of person who undergoes treatment in such a programme as the two people involved are very different – one of which has never actually committed a personal offence against a child but who sought treatment after struggling with his desires.

The programme is a rare look at the sort of treatment programme that is often vilified by the press, despite strong evidence that such programmes reduce offending and keep the public safer as a result.

There are a few places in the piece that I thought could have been done better, but in general, it’s unlikely you’ll get a more stark insight into a difficult and controversial area.

Link to 360documentaries on sex offender treatment programme.

A nasty case of misery

BBC Radio 4 has a short but excellent programme on the increasing medicalisation of human sadness which notes that even everyday talk about difficult but necessary life events is being increasingly couched in medical terms.

The writer and presenter of the piece, journalist Mary Kenny, notes, for example, how the concept of trauma is being increasingly applied to mourning, previously considered a painful but normal response to tragic circumstances. She also tackles how this tendency is being reflecting in the ongoing widening of the criteria for mental illness.

Kenny’s piece neither relies on tired simplifications of ‘evil drug companies’ nor falls back on simple explanations for mental illness and makes for a insightful short analysis of how our understanding of human distress is changing.

Unfortunately, you can only listen to a streamed version of the piece and it will disappear in four days, so catch it while you can.

Link to ‘Medicalising Melancholy’ on BBC Radio 4.
Link to article on BBC News website based on the programme.

The taste of the past

The latest edition of The Psychologist has a fascinating article on ‘sensory history’ – the practice of investigating how people from the past differently interpreted and understood sensory experiences.

I was first alerted to the idea by a book review we covered back in 2009 which noted that the superstition of the ‘evil eye’ – where you can curse someone by looking at them – makes more sense when you realise people believed that the eyes actively emitted rays rather than passively receiving them.

This new article is by sensory historian Mark Smith, author of the book Sensing the Past, who examines how the meaning of the senses has changed over time.

This part particularly caught my eye (pun intended) as it describes how the print revolution made the sense of sight seem more ‘truthful’ and ‘objective’:

In part, at least, historians of the sensate attend to the nonvisual senses principally because we have, for so long, assumed the supremacy of the eye in the human sensorium. Historical interest in smell, sound, touch and taste has been animated often because of the assumed ascendancy of vision that emerged following the print revolution and the developments of the Enlightenment, many of which supposedly elevated the eye as the arbiter of truth, the producer of perspective and balance (courtesy of the invention and subsequent dissemination of visual technologies such as the telescope, microscope and camera) and, in the process, diluted the value placed on the nonvisual, often proximate senses of hearing, olfaction, tasting, and touching.

It seems – or, at least, some sensory historians now theorise – that this supposed revolution in the senses was so thoroughgoing that moderns –at least those of the Western 18th-, 19th- and 20th-century variety – increasingly dismissed the other senses as reliable indicators of reason and truth and, instead, came to associate them with emotionalism or, more often than not, hardly worthy of sustained scholarly investigation.

Link to ‘The explosion of sensory history’.

Full disclosure: I’m an unpaid associate editor and occasional columnist for The Psychologist who has trouble sensing breakfast, let alone history.

Inattention to details

Neuroskeptic has excellent coverage of the recent headline-making study on the genetics of ADHD that was overly-hyped as the ‘first direct genetic link’ to the disorder and overly-slammed as a drug company ploy.

For example, BBC News has a report on the study where you can see researcher Anita Thapar making some unrealistic claims for the significance of the interesting-but-preliminary study while the science-retardant child psychologist Oliver James counters by cherry picking evidence (and not even very accurately).

Neuroskeptic does a great job of untangling the actual import of the research and discusses why the finding of copy-number variations or CNVs in about 16% of the ADHD kids compared to 7.5% of the controls is neither a ‘direct genetic link’ nor evidence against the idea that the condition is ‘socially constructed’.

However, I was particularly drawn by Thapar’s comments that discovering the genetic component “should address the issue of stigma.”

The common idea is that if we can demonstrate a particular mental disorder is a ‘brain disease’ or the result of a biological dysfunction people who have the condition will be less stigmatised due to a vague notion that their behaviour ‘is not their fault’.

Unfortunately, studies to date have shown that biological explanations for mental disorder actually increase stigma in public, patients and mental health professionals because the affected people are typically seen as more unpredictable and dangerous than when social or psychological explanations are given.

It is genuinely important that we understand the genetic influences to behavioural problems, including those that get classified as ADHD, and this new study is a small but important step toward that aim.

But we kid ourselves if we think this evidence automatically decreases stigma and we do society a disservice if we make our acceptance and compassion for people with behavioural difficulties dependent on certain types of scientific explanation.

Link to excellent Neuroskeptic piece on genetics and ADHD study.