Take a moment to consider how old you feel. Not your actual, biological age – but your own subjective feelings.
Abundant research during the past few decades has shown that this “subjective age” can be a powerful predictor of your health, including the risk of depression, diabetes and hypertension, dementia, and hospitalisation for illness and injury, and even mortality – better than your actual age. In each case, the younger you feel, the healthier you are.
The link probably goes in both directions. So while it’s true that ill-health may make you feel older, a higher subjective age could also limit your physical activity and increase feelings of vulnerability that make it hard to cope with stress – both of which could, independently, lead to illness. The result could even be a vicious cycle, where feelings of accelerated ageing lead you to become more inactive, and the resulting ill-health then further confirms your pessimistic views. And as I recently wrote for BBC Future, understanding this process could be essential for designing more effective health programmes.
Yannick Stephan at the University of Montpellier has led much of the work examining this phenomenon, and his latest paper, published with colleagues in the journal Intelligence, extends this understanding by revealing a surprising link with IQ. According to this research, the more intelligent we are in our late teens and early 20s, the younger we will feel in our 70s – and this may also be reflected in various markers of biological ageing.
A systematic survey in the US of people’s beliefs about their own intelligence – the first for 50 years – has shown that was true then is also the case in the modern era: a majority of people think they are smarter than average.
The research, led by Patrick Heck from the Geisinger Health System and published in PLOS One, combined an online survey and phone survey, with each involving 750 people reflecting a cross-section of the US population, balanced in terms of sex, age, education levels and race.
Across both surveys, 65 per cent of participants agreed with the statement “I am more intelligent than the average person.” Around 70 per cent of men versus 60 per cent of women made the above-average claim, and a similar pattern was found in the young and old. There were also no clear racial differences.
This research accords with both the half-century old study from the Russell Sage Foundation, and more recent research that suggests there is an overconfidence bias in the general population. The trouble is that most of the work following the Foundation’s study has often come from self-selecting or convenience samples that are unlikely to be representative of the wider population, or from students, who may be special cases, struggling, for instance, to envisage what the average person is like from their campus existence.
The new surveys also validate another cornerstone of overconfidence research: that the least intelligent tend to be the most overconfident. While university graduates (who are typically one standard deviation higher than average in intelligence) collectively tended to slightly underestimate their intelligence, those participants whose highest qualification was a high school diploma collectively over-shot in estimating theirs. Heck’s team conclude “that American’s self-flattering beliefs about intelligence are alive and well several decades after their discovery was first reported.”
Intelligence is a concept that some people have a hard time buying. It’s too multifaceted, too context-dependent, too Western. The US psychologist Edwin Boring encapsulated this scepticism when he said “measurable intelligence is simply what the tests of intelligence test.” Yet the scientific credentials of the concept are undimmed, partly because intelligence is strongly associated with so many important outcomes in life. Now Utah Valley University researchers Russell Warne and Cassidy Burningham have released evidence that further strengthens the case for intelligence being a valid and useful concept. Their PsyArXiv pre-print presents a cross-study analysis suggesting a single intelligence-like factor underpins mental performance across a wide range of non-western cultures.
Basic neuroscience teaches us how individual brain cells communicate with each other, like neighbours chatting over the garden fence. This is a vital part of brain function. Increasingly however neuroscientists are zooming out and studying the information processing that happens within and between neural networks across the entire brain, more akin to the complex flow of digital information constantly pulsing around the globe.
This has led them to realise the importance of what they call “brain entropy” – intense complexity and irregular variability in brain activity from one moment to the next, also marked by greater long-distance correlations in neural activity. Greater entropy, up to a point, is indicative of more information processing capacity, as opposed to low entropy – characterised by orderliness and repetition – which is seen when we are in a deep sleep or coma.
A new study in Scientific Reports is the first to examine whether and how ingesting a psychostimulant – in this case caffeine – affects brain entropy. The results show caffeine causes a widespread increase in cerebral entropy. This dose of neural anarchy is probably welcome, especially considered in light of another new paper, in PLOS One, which finds greater brain entropy correlates with higher verbal IQ and reasoning ability.
A pre-registered mass replication attempt published in Perspectives on Psychological Science has raised doubts about another celebrated psychology finding. The collaboration between 40 laboratories found scant evidence for the so-called “Professor Prime”, undermining the famous finding that when people imagined themselves as a professor rather than a football hooligan it led them to perform better on a trivia quiz.
A researcher in human intelligence at Utah Valley University has analysed the 29 best-selling introductory psychology textbooks in the US – some written by among the most eminent psychologists alive – and concluded that they present a highly misleading view of the science of intelligence (see full list of books below).
Russell T Warne and his co-authors found that three-quarters of the books contain inaccuracies; that the books give disproportionate coverage to unsupported theories, such as Gardner’s “multiple intelligencies”; and nearly 80 per cent contain logical fallacies in their discussions of the topic.
A growth mindset – believing your capabilities can grow over time – can help us set self-improvement goals, consider mistakes as a step towards mastery, and remain upbeat when facing tribulation. Psychologists are excited by the ways we can help develop such mindsets, particularly towards creativity and intelligence, but some studies have found the impact less impressive than earlier research had suggested. Now researchers are hungry to understand the individual characteristics that might prevent these interventions making an impact on some people.
New research in the British Journal of Social Psychology has investigated one possible candidate – political ideology, specifically a perspective known as “social dominance orientation”. If you are invested in preserving the status quo, perhaps that encourages you to see social relations as inevitable, as “just the way things are” – an essentialist, fixed view of the world that seems to carry over to how you view human capability.
Intelligence tests are meant to tell you something about a person’s inherent abilities. But what if the results are distorted by the motivation to perform well? That would undermine the tests’ validity and have important implications for their use in education and recruitment.
A simple way to find out whether motivation affects intelligence test performance is to offer people a financial incentive for doing well and see if this helps them get a higher score. A paper in the British Journal of Psychology has done this, finding that while a financial incentive boosted people’s self-declared effort levels, it failed to lift their performance. This result is good news for the validity of intelligence testing. Or as the paper’s author, Gilles Gignac at the University of Western Australia, put it: “The position of a causal effect of test-taking motivation on intelligence test performance in adults does not, yet, appear to be clearly tenable”.
From the beginning of recorded time, humanity has been fascinated by the figure of the wise person, wending their path through the tribulations of life, and informing those willing to learn. What sets them apart? Maybe that’s the wrong question. In a new review in European Psychologist, Igor Grossman of the University of Waterloo argues that understanding wisdom involves taking the wise off their pedestal, and seeing wisdom as a set of processes that we can all tap into, with the right attitude, and in the right context.
Picture yourself aged 11: who was your best friend and how smart were they? The answer may have shaped your life more than you think. A new study published as a pre-print at PsyArXiv reports that participants’ IQ at age 15 was correlated with the IQ of whomever was their best friend years earlier, when that friend was aged 11, even after factoring out the participants’ own earlier intelligence, as well as a host of other potentially confounding variables.
We already know, thanks to previous research, that our school-age peers shape our personalities, our powers of self-control, and the chances that we’ll get into trouble, so it’s to be expected that they also affect our intelligence (and we theirs). Surprisingly, however, this possibility had not been studied before now. “Our findings add … another layer of evidence for the important and pervasive influence of peers on a host of traits during adolescence,” the researchers said.