The placebo effect usually triggers an eye-brow raise or two among even the most hard-nosed of skeptics. We may not be able to forecast the future or move physical objects with our minds, but the placebo effect is nearly as marvellous (Ben Goldacre once called it the “coolest, strangest thing in medicine”).
The term “placebo effect” is short-hand for how our mere beliefs about the effectiveness of an inert treatment or intervention can lead to demonstrable health benefits and cognitive changes – an apparently incontrovertible demonstration of the near-magical power of mind over matter. It’s not literally magic, of course. Our beliefs are the subjective echo of physical processes in the brain – and it’s this constellation of neurochemical and electrical events , and their downstream effects, that underlies the placebo phenomenon (in some cases the placebo effect can also be interpreted as a form of conditioned response, in which a learned physiological reaction occurs in the absence of the original trigger).
There is another angle to this topic. To research psychologists, the placebo effect isn’t always a phenomenon of wonder, but a methodological nuisance. Researchers must go to extreme lengths to rule out the influence of participant expectations, so as to establish which observed effects are truly attributable to an intervention.
Here, in a celebration of the mysterious and maddening placebo effect, and to help inspire future research into this most fascinating aspect of human (and animal) psychology, we digest 10 amazing placebo-related findings:
“Look. You can’t plan out your life. What you have to do is first discover your passion—what you really care about.” Barack Obama, as quoted by David Gergen (cited in Jachimowicz et al, 2018).
If, like many, you are searching for your calling in life – perhaps you are still unsure whether psychology is for you, or which area of the profession aligns with what you most care about – here are five digested research findings worth taking into consideration:
It’s a question that’s reverberated through the ages – are we humans, though imperfect, essentially kind, sensible, good-natured creatures? Or deep down are we wired to be bad, blinkered, idle, vain, vengeful and selfish? There are no easy answers and there’s clearly a lot of variation between individuals, but this feature post aims to shine some evidence-based light on the matter. Here in the first part of a two-part feature – and deliberately side-stepping the obviously relevant but controversial and already much-discussed Milgram, Zimbardo and Asch studies – we digest 10 dispiriting findings that reveal the darker and less impressive aspects of human nature:
Around the world, more people than ever are locked up in prisons – estimated to be in excess of 11 million people, up by almost 20 per cent since the turn of the millennium (pdf). According to a recent House of Commons Briefing Paper the rate of increase is even higher than this in the UK where prison populations are at a record high. Many of these incarcerated individuals have intensifying mental health needs – for instance, the same briefing paper reports that UK rates of self-harm in prisoners were 25 per cent higher in 2015 than in 2014. Ahead of this week’s meeting of the All Party Parliamentary Group for Psychology on the topic of Mental Health in the Criminal Justice System, here we provide a digest of research into the mental health of prisoners.
In a neat example of real life echoing a classic psychology experiment (I’m referring to Asch), #thedress was enough to make you think your friends were gas lighting you – how could it be that you and they were looking at the exact same picture and yet seeing entirely different things?
Of course there are many optical illusions, including others that involve colour (see, for example, the “checker shadow” illusion, pictured right). What was special about #thedress was that it triggered a bimodal split in perceptual experience among the population. Also, many illusions trigger a fluctuating percept, but once someone perceives the dress one way, they usually keep seeing it that way.
Viral hits happen overnight. Science is slow, but it’s catching up. With the passing of the years, numerous studies into #thedress have now been published – 23 according to a new review. Here we present you with a fascinating digest of what’s been discovered so far about the famous frock – researchers have made progress, certainly, yet much remains mysterious, making this a humbling experience for perceptual science.
Johannes Eichstaedt was sitting in a coffee shop by Lake Atitlan in Guatemala when he received a slack about a tweet about a preprint. In 2015, the University of Pennsylvania psychologist and his colleagues published a headline-grabbing article linking heart disease to the language used on Twitter. They’d found that tweets emanating from US counties with high rates of heart disease mortality tended to exhibit high levels of negative emotions such as anger, anxiety, disengagement, aggression, and hate. The study, published in Psychological Science, has proven influential, already accruing over 170 citations. But three years later, the preprint authors Nick Brown and James Coyne from the University of Groningen claimed to have identified “numerous conceptual and methodological limitations”. Within the month, Eichstaedt and his colleagues issued a riposte, publishing their own preprint that claims further evidence to support their original conclusions.
As recent revelations surrounding Facebook and Cambridge Analytica have highlighted, corporations and political organisations attach a high value to social media data. But, Eichstaedt argues, that same data also offers rich insights into psychological health and well-being. With appropriate ethical oversight, social media analytics could promote population health and perhaps even save lives. That at least is its promise. But with big data come new challenges – as Eichstaedt’s “debate” with Brown and Coyne illustrates.
Ahead of the world heavyweight boxing championship reunification fight on March 31, 2018, featuring Great Britain’s Anthony Joshua versus Joseph Parker from New Zealand – the first time that two undefeated heavyweight world champions competed in the UK – we trawled the psychology literature looking for intriguing findings involving boxers and other sporting fighters. From the curse of the pre-match smile, to the cognitive biases that sway your choice of greatest ever boxer, here’s the psychology of fighting, digested:
Psychologists have long studied chimps and other animals with two principal, related aims: to find out the capabilities of the animal mind, and to discover what makes us truly unique, if anything. This is a challenging field. As any pet owner knows, it’s tempting to project a human interpretation onto animal behaviour. Researchers, especially when they’ve spent many years studying the same animal, can fall victim to this very bias (you’ll see a theme of this field is the powerful, close bonds frequently formed between psychologist and animal). At the same time, though, there is also a temptation to overestimate our human uniqueness. Which emotions and capabilities are exclusively human? Tool use, perspective taking and deceit were once contenders, but no more, and the list is getting shorter all the time.
This Digest feature post is a celebration of the contribution that animals have made to psychology, including eight that we’ve come to know on first-name terms:
Basic facts about the brain are a key part of many introductory psychology courses, including information about brain cells. For instance, for years, students (and the public) have been taught that, thanks to the ageing process, the older we get, the more brain cells we lose. But as outlined in a new review in the Journal of Chemical Neuroanatomy by Christopher von Bartheld at the University of Nevada, many established facts about brain cells (like the idea we lose lots of them as we get older) have been shown by modern techniques to be misconceptions. Taken mostly from the review, here are four myths about brain cells, plus one unresolved issue.
There are behavioural differences, on average, between the sexes – few would dispute that. Where the debate rages is over how much these differences are the result of social pressures versus being rooted in our biology (the answer often is that there is a complex interaction between the two).
For example, when differences are observed between girls and boys, such as in preferences for play, one possibility is that this is partly or wholly because of the contrasting ways that girls and boys are influenced by their peers, parents and other adults (because of the ideas they have about how the sexes ought to behave). Studying non-human primates allows us to identity sex differences in behavior that can’t be due to human culture and gender beliefs.
Learning more about the biological roots of behavioural sex differences should not be used as an excuse for harmful stereotyping or discrimination, but it can help us better understand our human nature and the part that evolved sex differences play in some of the most important issues that affect our lives, including around diversity, relationships, mental health, crime and education.
“Many sex differences in behavioral development exist in nonhuman primates,” she writes, “despite a comparative lack of sex-biased treatment by mothers and other social partners”. Here is a digested account of five of these behavioural sex differences: