rational judges, not extraneous factors in decisions

The graph tells a drammatic story of irrationality, presented in the 2011 paper Extraneous factors in judicial decisions. What it shows is the outcome of parole board decisions, as ruled by judges, against the order those decisions were made. The circles show the meal breaks taken by the judges.

parole_decisionsAs you can see, the decisions change the further the judge gets from his/her last meal, dramatically decreasing from around 65% chance of a favourable decision if you are the first case after a meal break, to close to 0% if you are the last case in a long series before a break.

In their paper, the original authors argue that this effect of order truly is due to the judges’ hunger, and not a confound introduced by some other factor which affects the order of cases and their chances of success (the lawyers sit outside the closed doors of the court, for example, so can’t time their best cases to come just after a break – they don’t know when the judge is taking a meal; The effect survives additional analysis where severity of prisoner’s crime and length of sentence are factored it; and so on). The interpretation is that as the judges tire they more and more fall back on a simple heuristic – playing safe and refusing parole.

This seeming evidence of the irrationality of judges has been cited hundreds of times, in economics, psychology and legal scholarship. Now, a new analysis by Andreas Glöckner in the journal Judgement and Decision Making questions these conclusions.

Glöckner’s analysis doesn’t prove that extraneous factors weren’t influencing the judges, but he shows how the same effect could be produced by entirely rational judges interacting with the protocols required by the legal system.

The main analysis works like this: we know that favourable rulings take longer than unfavourable ones (~7 mins vs ~5 mins), and we assume that judges are able to guess how long a case will take to rule on before they begin it (from clues like the thickness of the file, the types of request made, the representation the prisoner has and so on). Finally, we assume judges have a time limit in mind for each of the three sessions of the day, and will avoid starting cases which they estimate will overrun the time limit for the current session.

It turns out that this kind of rational time-management is sufficient to  generate the drops in favourable outcomes. How this occurs isn’t straightforward and interacts with a quirk of original author’s data presentation (specifically their graph shows the order number of cases when the number of cases in each session varied day to day – so, for example, it shows that the 12th case after a break is least likely to be judged favourably, but there wasn’t always a 12 case in each session. So sessions in which there were more unfavourable cases were more likely to contribute to this data point).

This story of claim and counter-claim shows why psychologists prefer experiments, since only then can you truly isolate causal explanations (if you are a judge and willing to go without lunch please get in touch). Also, it shows the benefit of simulations for extending the horizons of our intuition. Glöckner’s achievement is to show in detail how some reasonable assumptions – including that of a rational judge – can generate a pattern which hitherto seemed only explainable by the influence of an irrelevant factor on the judges decisions. This doesn’t settle the matter, but it does mean we can’t be so confident that this graph shows what it is often claimed to show. The judges decisions may not be irrational after all, and the timing of the judges meal breaks may not be influencing parole decision outcome.

Original finding: Danziger, S., Levav, J., & Avnaim-Pesso, L. (2011). Extraneous factors in judicial decisions. Proceedings of the National Academy of Sciences, 108(17), 6889-6892.

New analysis: Glöckner, A. (2016). The irrational hungry judge effect revisited: Simulations reveal that the magnitude of the effect is overestimated. Judgment and Decision Making, 11(6), 601-610.

Elsewhere I have written about how evidence of human irrationality is often over-egged : For argument’s sake: evidence that reason can change minds

 

Is psychosis an ‘immune disorder’?

A fascinating new study has just been published which found evidence for the immune system attacking a neuroreceptor in the brain in a small proportion of people with psychosis. It’s an interesting study that probably reflects what’s going to be a cultural tipping point for the idea of ‘immune system mental health problems’ or ‘madness as inflammation disorder’ but it’s worth being a little wary of the coming hype.

This new study, published in The Lancet Psychiatry, did blood tests on people who presented with their first episode of psychosis and looked for antibodies that attack specific receptors in the brain. Receptors are what receive neurotransmitters – the brain’s chemical signals – and allow information to be transferred around the nervous system, so disruption to these can cause brain disturbances.

The most scientifically interesting finding is that the research team found a type of antibody that attacks NMDA receptors in 7 patients (3%) out of 228, but zero controls.

The study found markers for other neuroreceptors that the immune system was attacking, but the reason the NMDA finding is so crucial is because it shows evidence of a condition called anti-NMDA receptor encephalitis which is known to cause episodes of psychosis that can be indistinguishable from ‘regular’ psychosis but for which the best treatment is dealing with the autoimmune problem.

It was only discovered in 2007 but there has been a long-running suspicion that it may be the best explanation for a small minority of cases of psychosis which can be easily misdiagnosed as schizophrenia.

Importantly, the findings from this research have been supported by another independent study that has just been published online. The two studies used different ranges for the concentration of NMDA antibodies they measured, but they came up with roughly the same figures.

It also chimes with a growing debate about the role of the immune system in mental health. A lot of this evidence is circumstantial but suggestive. For example, many of the genes associated (albeit weakly) with the diagnosis of schizophrenia are involved in the immune system – particularly in coding proteins for the major histocompatibility complex.

However, it’s worth being a little circumspect about this new enthusiasm for thinking of psychosis as an ‘immune disorder’.

Importantly, these new studies did blood tests, rather than checking cerebrospinal fluid – the fluid that your brain floats around in which lies on the other side of the blood-brain barrier, so we can’t be sure that these antibodies were actually affecting the brain in everyone found to have them. It’s likely, but not certain.

Also, we’re not sure to what extent anti-NMDA antibodies contribute to the chance of developing psychosis in everyone. Certainly there are some cases where it seems to be the main cause, but we’re not sure how that holds for all.

It’s also worth bearing in mind that the science over the role of the genes associated with the schizophrenia diagnosis in the immune system is certainly not settled. A recent large study compared the role of these genes in schizophrenia to known autoimmune disorders and concluded that the genes just don’t look like they’re actually impacting on the immune system.

There’s also a constant background of cultural enthusiasm in psychiatry to identify ‘biomarkers’ and anything that looks like a clear common biological pathway even for a small number of cases of ‘psychiatric’ problem gets a lot of airtime.

Curiously, in this case, Hollywood may also play a part.

A film called Brain On Fire has just been shown to film festivals and is being tested for a possible big release. It’s based on the (excellent) book of the same name by journalist Susannah Cahalan and describes her experience of developing psychosis only for it later to be discovered that she had anti-NMDA receptor encephalitis.

Hollywood has historically had a big effect on discussions about mental health and you can be sure that if the movie becomes a hit, popular media will be alive with discussions on ‘whether your mental health problems are really an immune problem’.

But taking a less glitzy view, in terms of these new studies, they probably reflect that a small percentage of people with psychosis, maybe 1-2%, have NMDA receptor-related immune problems that play an important role in the generation of their mental health difficulties.

It’s important not to underestimate the importance of these findings. It could potentially translate into more effective treatment for millions of people a year globally.

But in terms of psychosis as a whole, for which we know social adversity in its many forms plays a massive role, it’s just a small piece of the puzzle.
 

Link to locked Lancet Psychiatry study.

How liars create the illusion of truth

Repetition makes a fact seem more true, regardless of whether it is or not. Understanding this effect can help you avoid falling for propaganda, says psychologist Tom Stafford.

“Repeat a lie often enough and it becomes the truth”, is a law of propaganda often attributed to the Nazi Joseph Goebbels. Among psychologists something like this known as the “illusion of truth” effect. Here’s how a typical experiment on the effect works: participants rate how true trivia items are, things like “A prune is a dried plum”. Sometimes these items are true (like that one), but sometimes participants see a parallel version which isn’t true (something like “A date is a dried plum”).

After a break – of minutes or even weeks – the participants do the procedure again, but this time some of the items they rate are new, and some they saw before in the first phase. The key finding is that people tend to rate items they’ve seen before as more likely to be true, regardless of whether they are true or not, and seemingly for the sole reason that they are more familiar.

So, here, captured in the lab, seems to be the source for the saying that if you repeat a lie often enough it becomes the truth. And if you look around yourself, you may start to think that everyone from advertisers to politicians are taking advantage of this foible of human psychology.

But a reliable effect in the lab isn’t necessarily an important effect on people’s real-world beliefs. If you really could make a lie sound true by repetition, there’d be no need for all the other techniques of persuasion.

One obstacle is what you already know. Even if a lie sounds plausible, why would you set what you know aside just because you heard the lie repeatedly?

Recently, a team led by Lisa Fazio of Vanderbilt University set out to test how the illusion of truth effect interacts with our prior knowledge. Would it affect our existing knowledge? They used paired true and un-true statements, but also split their items according to how likely participants were to know the truth (so “The Pacific Ocean is the largest ocean on Earth” is an example of a “known” items, which also happens to be true, and “The Atlantic Ocean is the largest ocean on Earth” is an un-true item, for which people are likely to know the actual truth).

Their results show that the illusion of truth effect worked just as strongly for known as for unknown items, suggesting that prior knowledge won’t prevent repetition from swaying our judgements of plausibility.

To cover all bases, the researchers performed one study in which the participants were asked to rate how true each statement seemed on a six-point scale, and one where they just categorised each fact as “true” or “false”. Repetition pushed the average item up the six-point scale, and increased the odds that a statement would be categorised as true. For statements that were actually fact or fiction, known or unknown, repetition made them all seem more believable.

At first this looks like bad news for human rationality, but – and I can’t emphasise this strongly enough – when interpreting psychological science, you have to look at the actual numbers.

What Fazio and colleagues actually found, is that the biggest influence on whether a statement was judged to be true was… whether it actually was true. The repetition effect couldn’t mask the truth. With or without repetition, people were still more likely to believe the actual facts as opposed to the lies.

This shows something fundamental about how we update our beliefs – repetition has a power to make things sound more true, even when we know differently, but it doesn’t over-ride that knowledge

The next question has to be, why might that be? The answer is to do with the effort it takes to being rigidly logical about every piece of information you hear. If every time you heard something you assessed it against everything you already knew, you’d still be thinking about breakfast at supper-time. Because we need to make quick judgements, we adopt shortcuts – heuristics which are right more often than wrong. Relying on how often you’ve heard something to judge how truthful something feels is just one strategy. Any universe where truth gets repeated more often than lies, even if only 51% vs 49% will be one where this is a quick and dirty rule for judging facts.

If repetition was the only thing that influenced what we believed we’d be in trouble, but it isn’t. We can all bring to bear more extensive powers of reasoning, but we need to recognise they are a limited resource. Our minds are prey to the illusion of truth effect because our instinct is to use short-cuts in judging how plausible something is. Often this works. Sometimes it is misleading.

Once we know about the effect we can guard against it. Part of this is double-checking why we believe what we do – if something sounds plausible is it because it really is true, or have we just been told that repeatedly? This is why scholars are so mad about providing references – so we can track the origin on any claim, rather than having to take it on faith.

But part of guarding against the illusion is the obligation it puts on us to stop repeating falsehoods. We live in a world where the facts matter, and should matter. If you repeat things without bothering to check if they are true, you are helping to make a world where lies and truth are easier to confuse. So, please, think before you repeat.

This is my BBC Future column from the other week, the original is here. For more on this topic, see my ebook : For argument’s sake: evidence that reason can change minds (smashwords link here)

reinforcing your wiser self

phoneNautilus has a piece by David Perezcassar on how technology takes advantage of our animal instinct for variable reward schedules (Unreliable rewards trap us into addictive cell phone use, but they can also get us out).

It’s a great illustrated read about the scientific history of the ideas behind ‘persuasive technology’, and ends with a plea that perhaps we can hijack our weakness for variable reward schedules for better ends:

What is we set up a variable reward system to reward ourselves for the time spent away fro our phones & physically connecting with others? Even time spend meditating or reading without technological distractions is a heroic endeavor worthy of a prize

Which isn’t a bad idea, but the pattern of the reward schedule is only one factor in what makes an activity habit forming. The timing of a reward is more important than the reliability – it’s easier to train in habits with immediate than delayed rewards. The timing is so crucial that in the animal learning literature even a delay of 2 seconds between a lever press and the delivery of a food pellet impairs learning in rats. In experiments we did with humans a delay of 150ms we enough to hinder our participants connecting their own actions with a training signal.

So the dilemma for persuasive technology, and anyone who wants to free themselves from its hold, is not just how phones/emails/social media structure our rewards, but also the fact that they allow gratification at almost any moment. There are always new notifications, new news, and so phones let us have zero delay for the reward of checking our phones. If you want to focus on other things, like being a successful parent, friend or human the delays on the rewards of these are far larger (not to mention more nebulous).

The way I like to think about it is the conflict between the impatient, narrow, smaller self – the self that likes sweets and gossip and all things immediate gratification – and the wider, wiser self – the self than invests in the future and carers about the bigger picture. That self can win out, does win out as we make our stumbling journey into adulthood, but my hunch is we’re going to need a different framework from the one of reinforcement learning to do it

Nautilus article: Unreliable rewards trap us into addictive cell phone use, but they can also get us out

Mindhacks.com: post about reinforcement schedules, and how they might be used to break technology compulsion (from 2006 – just sayin’)

George Ainslie’s book Breakdown of Will is what happens if you go so deep into the reinforcement learning paradigm you explode its reductionism and reinvent the notion of the self. Mind-alteringly good.

Do students know what’s good for them?

Of course they do, and of course they don’t.

Putting a student at the centre of their own learning seems like fundamental pedagogy. The Constructivist approach to education emphasises the need for knowledge to reassembled in the mind of the learner, and the related impossibility of its direct transmission from the mind of the teacher. Believe this, and student input into how they learn must follow.

At the same time, we know there is a deep neurobiological connection between the machinery of reward in our brain, and that of learning. Both functions seem to be entangled in the subcortical circuitry of a network known as the basal ganglia. It’s perhaps not surprising that curiosity, which we all know personally to be a powerful motivator of learning, activates the same subcortical circuitry involved in the pleasurable anticipation of reward. Further, curiosity enhances memory, even for things you learn while your curiosity is aroused about something else.

This neurobiological alignment of enjoyment and learning isn’t mere coincidence. When building learning algorithms for embedding in learning robots, the basic rules of learning from experience have to be augmented with a drive to explore – curiosity! – so that they don’t become stuck repeating suboptimal habits. Whether it is motivated by curiosity or other factors, exploration seems to support enhanced learning in a range of domains from simple skills to more complex ideas.

Obviously we learn best when motivated, and when learning is fun, and allowing us to explore our curiosity is a way to allow both. However, putting the trajectory of their experience into students’ hands can go awry.

False beliefs impede learning

One reason is false beliefs about how much we know, or how we learn best. Psychologists studying memory have long documented such metacognitive errors, which include overconfidence, and a mistaken reliance on our familiarity with a thing as a guide to how well we understand it, or how well we’ll be able to recall it when tested (recognition and recall are in fact different cognitive processes). Sure enough, when tested in experiments people will over-rely on ineffective study strategies (like rereading, or reviewing the answers to questions, rather than testing their ability to generate the answers from the questions). Cramming is another ineffective study strategy, with experiment after experiment showing the benefit of spreading out your study rather than massing it all together. Obviously this requires being more organised, but my belief is that a metacognitive error supports students’ over-reliance on cramming – cramming feels good, because, for a moment, you feel familiar with all the information. The problem is that this feel-good familiarity isn’t the kind of memory that will support recall in an exam, but immature learners often don’t realise the extent of that.

In agreement with these findings from psychologists, education scholars have reacted against pure student-led or discovery learning, with one review summarising the findings from multiple distinct research programmes taking place over three decades: “In each case, guided discovery was more effective than pure discovery in helping students learn and transfer”.

The solution: balancing guided and discovery learning

This leaves us at a classic “middle way”, where pure student-led or teacher-led learning is ruled out. Some kind of guided exploration, structured study, or student choice in learning is obviously a necessity, but we’re not sure how much.

There’s an exciting future for research which informs us what the right blend of guided and discovery learning is, and which students and topics suit which exact blend. One strand of this is to take the cognitive psychology experiments which demonstrate a benefit of active choice learning over passive instruction and to tweak them so that we can see when passive instruction can be used to jump-start or augment active choice learning. One experiment from Kyle MacDonald and Michael Frank of Stanford University used a highly abstract concept learning task in which participants use trial and error to figure out a categorisation of different shapes. Previous research had shown that people learned faster if they were allowed to choose their own examples to receive feedback on, but this latest iteration of the experiment from MacDonald and Frank showed that an initial session of passive learning, where the examples were chosen for the learner boosted performance even further. Presumably this effect is due to the scaffolding in the structure of the concept-space that the passive learning gives the learner. This, and myriad experiments, are possible to show when and how active learning and instructor-led learning can be blended.

Education is about more than students learning the material on the syllabus. There is a meta-goal of producing students who are better able to learn for themselves. The same cognitive machinery in all of us might push us towards less effective strategies. The simple fact of being located within our own selfish consciousness means that even the best performers in the world need a coach to help them learn. But as we mature we can learn to better avoid pitfalls in our learning and evolve into better self-determining students. Ultimately the best education needs to keep its focus on that need to help each of us take on more and more responsibility for how we learn, whether that means submitting to others’ choices or exploring things for ourselves – or, often, a bit of both.

This post originally appeared on the NPJ ‘Science of Learning’ Community

The hidden history of war on terror torture

The Hidden Persuaders project has interviewed neuropsychologist Tim Shallice about his opposition to the British government’s use of ‘enhanced interrogation’ in the Northern Ireland conflict of the 1970s – a practice eventually abandoned as torture.

Shallice is little known to the wider public but is one of the most important and influential neuropsychologists of his generation, having pioneered the systematic study of neurological problems as a window on typical cognitive function.

One of his first papers was not on brain injury, however, it was an article titled ‘Ulster depth interrogation techniques and their relation to sensory deprivation research’ where he set out a cognitive basis for why the ‘five techniques’ – wall-standing, hooding, white noise, sleep deprivation, and deprivation of food and drink – amounted to torture.

Shallice traces a link between the use of these techniques and research on sensory deprivation – which was investigated both by regular scientists for reasons of scientific curiosity, and as we learned later, by intelligence services while trying to understand ‘brain washing’.

The use of these techniques in Northern Ireland was subject to an official investigation and Shallice and other researchers testified to the Parker Committee which led Prime Minister Edward Heath to ban the practice.

If those techniques sound eerily familiar, it is because they formed the basis of interrogation practices at Guantanamo Bay and other notorious sites in the ‘war on terror’.

The Hidden Persuaders is a research project at Birkbeck, University of London, which is investigating the history of ‘brainwashing’. It traces the practice to its use by the British during the colonisation of Yemen, who seemed to have borrowed it off the KGB.

And if you want to read about the modern day effects of the abusive techniques, The New York Times has just published a disturbing feature article about the long-term consequences of being tortured in Guantanamo and other ‘black sites’ by following up many of the people subject to the brutal techniques.
 

Link to Hidden Persuaders interview with Tim Shallice.
Link to NYT on long-term legacy of war on terror torture.

Does ‘brain training’ work?

You’ve probably heard of “brain training exercises” – puzzles, tasks and drills which claim to keep you mentally agile. Maybe, especially if you’re an older person, you’ve even bought the book, or the app, in the hope of staving off mental decline. The idea of brain training has widespread currency, but is that due to science, or empty marketing?

Now a major new review, published in Psychology in the Public Interest, sets out to systematically examine the evidence for brain training. The results should give you pause before spending any of your time and money on brain training, but they also highlight what happens when research and commerce become entangled.

The review team, led by Dan Simons of the University of Illinois, set out to inspect all the literature which brain training companies cited in their promotional material – in effect, taking them at their word, with the rationale that the best evidence in support of brain training exercises would be that cited by the companies promoting them.

The chairman says it works

A major finding of the review is the poverty of the supporting evidence for these supposedly scientific exercises. Simons’ team found that half of the brain training companies that promoted their products as being scientifically validated didn’t cite any peer-reviewed journal articles, relying instead on things like testimonials from scientists (including the company founders). Of the companies which did cite evidence for brain training, many cited general research on neuroplasticity, but nothing directly relevant to the effectiveness of what they promote.

The key issue for claims around brain training is that practising these exercises will help you in general, or on unrelated tasks. Nobody doubts that practising a crossword will help you get better at crosswords, but will it improve your memory, your IQ or your ability to skim read email? Such effects are called transfer effects, and so called “far transfer” (transfer to a very different task than that trained) is the ultimate goal of brain training studies. What we know about transfer effect is reviewed in Simons’ paper.

Doing puzzles make you, well, good at doing puzzles.
Jne Valokuvaus/Shutterstock.com

As well as trawling the company websites, the reviewers inspected a list provided by an industry group (Cognitive Training Data of some 132 scientific papers claiming to support the efficacy of brain training. Of these, 106 reported new data (rather than being reviews themselves). Of those 106, 71 used a proper control group, so that the effects of the brain training could be isolated. Of those 71, only 49 had so called “active control” group, in which the control participants actually did something rather than being ignored by the the researchers. (An active control is important if you want to distinguish the benefit of your treatment from the benefits of expectation or responding to researchers’ attentions.) Of these 49, about half of the results came from just six studies.

Overall, the reviewers conclude, no study which is cited in support of brain training products meets the gold standard for best research practises, and few even approached the standard of a good randomised control trial (although note their cut off for considering papers missed this paper from late last year).

A bit premature

The implications, they argue, are that claims for general benefits of brain training are premature. There’s excellent evidence for benefits of training specific to the task trained on, they conclude, less evidence for enhancement on closely related tasks and little evidence that brain training enhances performance on distantly related tasks or everyday cognitive performance.

The flaws in the studies supporting the benefits of brain training aren’t unique to the study of brain training. Good research is hard and all studies have flaws. Assembling convincing evidence for a treatment takes years, with evidence required from multiple studies and from different types of studies. Indeed, it may yet be that some kind of cognitive training can be shown to have the general benefits that are hoped for from existing brain training exercises. What this review shows is not that brain training can’t work, merely that promotion of brain training exercises is – at the very least – premature based on the current scientific evidence.

Yet in a 2014 survey of US adults, over 50% had heard of brain training exercises and showed some credence to their performance enhancing powers. Even the name “brain training”, the authors of the review admit, is a concession to marketing – this is how people know these exercises, despite their development having little to do with the brain directly.

The widespread currency of brain training isn’t because of overwhelming evidence of benefits from neuroscience and psychological science, as the review shows, but it does rely on the appearance of being scientifically supported. The billion-dollar market in brain training is parasitic on the credibility of neuroscience and psychology. It also taps into our lazy desire to address complex problems with simple, purchasable, solutions (something written about at length by Ben Goldacre in his book Bad Science).

The Simons review ends with recommendations for researchers into brain training, and for journalists reporting on the topic. My favourite was their emphasis that any treatment needs to be considered for its costs, as well as its benefits. By this standard there is no commercial brain training product which has been shown to have greater benefits than something you can do for free. Also important is the opportunity cost: what could you be doing in the time you invest in brain training? The reviewers deliberately decided to focus on brain training, so they didn’t cover the proven and widespread benefits of exercise for mental function, but I’m happy to tell you now that a brisk walk round the park with a friend is not only free, and not only more fun, but has better scientific support for its cognitive-enhancing powers than all the brain training products which are commercially available.

The Conversation

Tom Stafford, Lecturer in Psychology and Cognitive Science, University of Sheffield

This article was originally published on The Conversation. Read the original article.