The most important psychology experiment never done?

To celebrate the 100th issue of the British Psychological Society’s Research Digest, the editor Christian Jarrett asked some of the world’s top psychologists to put their thinking caps on – and cast practicalities and ethics aside. 

Here we present a selection of the responses. For full versions, and for contributions from Alex Haslam, Annette Karmiloff-Smith, Richard Gregory and Society President Pam Maras, see

Saving the world

My experiment would begin with the construction of a comprehensive evidence-based educational programme of debiasing children and adolescents in multiple countries against malignant biases. I would randomly assign some students to receive this programme and others to receive standard educational curricula, and measure the long-term effects on well-validated attitudinal and behavioural measures of ideological fanaticism. The goal of this programme would be to inculcate not merely knowledge but wisdom, particularly aspects of wisdom that necessitate an awareness of one’s biases and limitations, and the capacity to recognise the merits of differing viewpoints.  Aside from the sheer pragmatic difficulty of administering a large scale curriculum across multiple countries, the greatest obstacle here is the surprising paucity of research on effective debiasing strategies. Nevertheless, at least some research suggests that encouraging individuals to seriously entertain viewpoints other than their own (e.g. ‘considering the opposite’) can partly immunise them against confirmation bias and related biases. Whether such educational debiasing efforts, implemented on a massive scale, would help to inoculate future generations against ideological fanaticism, is unknown. But launching such an endeavour via small-scale pilot studies would seem to be a worthwhile starting point.
- Scott Lilienfeld  


Maximum kindness, minimum drugs

John Bola recently reported a meta-analysis of clinical trials in which (a) the majority of patients were experiencing their first episode of schizophrenia, (b) some were unmedicated, and (c) the follow-up period was at least one year. Amazingly he could identify only six studies that met these criteria and the evidence suggested that unmedicated patients did at least as well and possibly better than medicated patients in the long term.

One of the studies was the controversial Soteria project from Leon Mosher, who devised a system of caring for acutely distressed psychotic patients with maximum kindness and minimum medication. No formal psychotherapy was provided, and the patients were looked after by untrained graduates who dealt with their difficulties with acceptance and emotional support. Despite evidence that Soteria patients did as well as first-episode patients treated in conventional psychiatric services, and the fact that Mosher was director of schizophrenia research for the US National Institute of Mental Health, NIMH closed down the project, probably because of pressure from the pharmaceutical industry.

In Britain, over the last decade, clinical psychologists have pioneered the development of cognitive-behavioural interventions for patients with psychosis, with promising results. However, CBT has always been offered in combination with conventional antipsychotic drugs. Even though Soteria and CBT come from different philosophical roots, close examination of the two approaches reveals many common features, including acceptance and the normalisation of symptoms. Psychiatric patients need to know the results of a clinical trial in which a CBT version of Soteria is compared to treatment as usual. Unfortunately, given the corrupting influence of the pharmaceutical industry, they are likely to have to wait for a very long time.
- Richard Bentall


Positive psychotherapy

For one hundred years psychotherapy has been where you go to talk about your troubles. Looking over hundreds of controlled outcome studies, it is a moderately effective process. But does the troubles part matter?

We have recently been looking at a process – called ‘positive psychotherapy’ – in which talking about what is good in your life is the central focus: strengths, virtues, flow, meaning, positive emotion, gratitude, hope and the like. We do not neglect troubles (depressed patients are socialised into the belief that troubles must be discussed and rapport would be undermined otherwise), but they are not the central focus and often forma segue into talking about strengths and meaning. Similarly, trouble-focused psychotherapy does not wholly neglect the positive side of life, but damage and its repair are the central focus. Trouble-focused therapy, unlike strength-focus therapy, is not much fun (worse, sometimes patients unravel and cannot be ravelled up again), is stigmatising, and has a considerable drop-out rate.

So let us finally test experimentally if it is troubles and repairing damage or building strength, meaning, and positive emotion that is the (more) active ingredient in psychotherapy: 200 depressed people, randomly assigned to therapists, trained to deliver either trouble-focused or strength-focused psychotherapy. It could even be within subjects in an ABAB design. And how would these compare to medication, or medication plus a strength- or trouble-focus?
- Martin Seligman


Switching the parents

In a 1995 paper in Psychological Review (see, I proposed that children’s personalities are shaped, not by their parents, but by the environment they encounter outside the home. This proposition, I said, implies that ‘children would develop into the same sort of adults if we left them in theirhomes, their schools, their neighbourhoods, and their cultural or subcultural groups, but switched all the parents around’.

The experiment is an important one but it cannot be done, and not only for practical and ethical reasons. For one thing, there’s no control group. We’d need two identical universes so that we could switch the parents around in one and leave them in place in the other. And we’d have to compare the children one by one, because my prediction wasn’t about group averages – it was about individual differences. But that wouldn’t work either, because we already know that two children with identical genes and essentially identical outside-the-home environments – namely, reared-together identical twins – don’t end up with the same adult personalities (a mystery I address in my 2006 book, No Two Alike.)

There are ways to work around these problems and show that, given a child’s genetic makeup and outside-the-home environment, the environment provided by the parents inside the home makes no noticeable difference in the long run. But it involves putting together evidence from many different sources. Evidence exists, for example, that identical twins reared by different parents are (on average) as similar in personality as those reared by the same parents; that adoptive siblings reared by the same parents are as dissimilar as those reared by different parents; that children reared by immigrant parents have the personality characteristics of the country they were reared in, rather than those of their parents’ native land; and that environmental differences within the family, such as those associated with birth order, leave no long-term marks on children’s personalities.

Is it less convincing to put together little bits of evidence than to point to a single grand experiment that proves one’s thesis conclusively? It certainly requires patience from one’s audience. But sometimes the piecemeal approach is all that is possible.
- Judith Rich Harris


Watching death

What happens when we die? Surely everyone wonders about this very human question, and it’s certainly caused much dissent between religion and science. While most scientists think that death must be the end of personal consciousness, most religious believers expect their soul or spirit to survive. How can we find the truth?

The most important experiment that’s never been done is to take fMRI or PET scans of people as they die; either those who really do go on to die, or those who suffer clinical death but are resuscitated. If this were done, we would be able to test theories about how ‘near death’ and mystical experiences are generated in the dying brain, and answer questions about the timing of the experiences. Perhaps even this would not resolve the final question once and for all, but it would certainly bring us a lot closer to knowing what happens when we die.

And why has it not been done? Because when someone is dying it is far more important to try to save their life than to do a scientific experiment. Neverthelesst could be done, and I hope that one day the technology will be so unobtrusive and easy to use that the ethical problem will disappear and we will be able to watch the dying brain as easily as we can now watch the living brain. I think it would help us face death with more equanimity.
- Susan Blackmore


Investigating delusions

In 1684, the dramatist Nathaniel Lee was admitted to Bethlem Hospital. He described the situation as one where ‘they called me mad, and I called them mad, and damn them, they outvoted me’. Over 300 years later, the difficulty of agreeing on whether someone’s belief is a paranoid delusion – a sign of psychotic mental illness – is still troubling psychologists.

Delusions are broadly defined as false, fixed beliefs that are held despite obvious evidence to the contrary. Sometimes, it’s a clear-cut case. If someone believes they are dead, a condition known as Cotard’s syndrome, you can be confident that the belief is a delusion. But more often the question relies on a judgement of how well the evidence supports the person's belief. What counts as evidence, and what counts as ‘well supported’, are often a matter of opinion. And we know, for example, that people diagnosed with schizophrenia are much more likely to suffer violence and discrimination. Perhaps, some of the paranoia is driven by genuine persecution.

So here’s the experiment. Everyone who walks into a mental health clinic is interviewed and their seemingly paranoid beliefs are noted. The mental health professional is asked to make a judgement on how delusional the belief might be. Then, each client is assigned a world-class private investigator, who is given the job of checking out all aspects of the belief, no matter how unusual. Is anyone in the neighbourhood persecuting the person? Are there really microphones in the house? Is there anyone who might have an interest in listening to their breathing patterns?

At the end, the professionals’ judgements are compared with the evidence from the investigation, and we get to see how good we are at distinguishing paranoia from realistic concerns. Just as importantly, the study would indicate where the borderlands of paranoia lie, giving usa better understanding of how the mind exaggerates our fears. Further research could look precisely at how genuine threats spark, ignite and become inflamed by the cognitive distortions of psychosis.

The experiment, of course, will never be run. Even ignoring the practical difficulties, it’s simply too intrusive and risks breaking client confidentiality. Thankfully though, good mental health care focuses on psychological distress, no matter what causes it. But the issue raises the important question of how much we rely on guesswork to judge other people’s reality.
- Vaughan Bell

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We again are missing the obvious.We are born with emotions fixed - therefore they are hereditary and that is what gives us our personality/character. The environment we grow up in only makes us act to fit in to this particular society. Deep down we still have the original emotions and this is what causes the conflict within ourselves.We do suffer from mental/psychological problems directly but from this conflict between what we feel we want to do and what we think we should do.