Fear really does have a smell

People often talk with some drama about the smell of fear, and yet who among us could describe what the odour is like? This vagueness seems to support the idea that fear as a smell is metaphorical - a way raconteurs through the ages have conveyed the tendency for fear to spread rapidly and invisibly from one person to the next. A new study, however, suggests there is, after all, a literal truth to the idea of fear being communicated through our sense of smell.

Alexander Prehn-Kristensen and colleagues bottled the smell of fear by placing cotton pads under the arms of students waiting to give an assessed oral presentation. For comparison the researchers also collected fear-free sweat from the armpits of students performing cycling exercises.

Next the researchers scanned the brains of 28 students while the two sources of odour were delivered to their noses using an adapted oxygen mask. Half the time, the students couldn't even perceive an odour. They were also unable to distinguish between the two odour sources, rating them as equally pleasant. Crucially, however, the participants' brain responses to the two odours did differ significantly.

The smell of sweat taken from students anxiously awaiting an oral exam led to proportionately greater activation in the participants across a swathe of brain areas known to be involved in empathy, emotion, representing other people's mental states and distinguishing the self from other. These included the insula, the precuneus, the cingulate gyrus, the fusiform cortex and the dorsomedial prefrontal cortex.

This finding, of the smell of fear triggering an emotional brain response in the absence of any conscious awareness, could help explain why we're sometimes moved by a whiff of fear in the air, without registering any accompanying sensory experience. "It is concluded that the human brain automatically guides physiological adjustments to chemosensory anxiety signals, without being dependent on conscious mediation," the researchers said.
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Prehn-Kristensen, A., Wiesner, C., Bergmann, T., Wolff, S., Jansen, O., Mehdorn, H., Ferstl, R., & Pause, B. (2009). Induction of Empathy by the Smell of Anxiety. PLoS ONE, 4 (6) DOI: 10.1371/journal.pone.0005987

It's called sfdkshfsk ... Stand back!

If you want people to recognise that a substance is dangerous - give it a complicated, hard-to-pronounce name. That's the implication of a new study that suggests we use a simple rule-of-thumb when judging risk. If something is easy to process and digest - for example, by virtue of being easy to pronounce - we tend to assume that it's familiar and safe. By contrast, if it seems hard to process, we assume it's novel and likely to be risky. These kinds of mental short cuts are known as heuristics and psychologists enjoy uncovering them because they show how our minds have evolved to cope with the constant storm of information and stimulation hurled their way.

In an initial study, Hyunjin Song and Norbert Schwarz found that student participants rated made-up food additives as more harmful if the they had hard-to-pronounce names such as Hnegripitrom, as compared with easier to pronounce names like Magnalroxate. A follow-up study suggested that this effect was partially explained by perceived novelty. That is, easy-to-pronounce additives were judged to be more familiar as well as being safer.

Another explanation for the effect of fluency on risk perception is that we enjoy fluency, which biases us to see things as less risky because risk is negative. A third study undermined this account. Student participants rated easy-to-pronounce fairground rides as less risky, even in the context of that risk being a good thing - in this case "exciting and adventurous".

"From an applied perspective, our findings suggest that fluency manipulations may offer a promising avenue for the management of perceived risk," the researchers said. "For example, disfluent product names may alert consumers to the risks posed by potentially hazardous products."

These findings add to a growing literature on the effects of fluency on our decision making. In 2006, for example, Adam Alter and Daniel Oppenheimer showed that people tend to invest more in companies with easy-to-pronounce names. Meanwhile, a 2005 study showed that writers who adopt a simple style are perceived to be more intelligent.

Link to full-text pdf via author website.
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Song, H., & Schwarz, N. (2009). If It's Difficult to Pronounce, It Must Be Risky. Psychological Science, 20 (2), 135-138 DOI: 10.1111/j.1467-9280.2009.02267.x

A computerised learning tool helps boost study effectiveness

Much of psychology's efforts over the last few decades have been spent on understanding the nature of memory. Increasingly, though, psychologists are beginning to apply what we've learned about memory, so as to help enhance people's performance. In 2007, the Digest reported on a study that investigated the optimal interval to leave between study periods if you want to remember material long term. Now Claudia Meltzer-Baddeley and Roland Baddeley have tested a related approach to study, known as adaptive training, and found that it too helps boost learning.

Adaptive training is a strategic form of study that ensures the learner spends more time focused on material they know less well and less time focused on already mastered material. This means that less familiar material is re-examined more frequently, while better mastered material is gradually left for longer and longer periods. It's possible to employ this kind of system by using stacks of learning cards, whereby correctly answered cards are placed on piles that are re-tested less often. However, there are computerised tools like "SuperMemo" that simplify and enhance this process, allowing the learner to say how confidently they answered each item, which in turn influences the likelihood of that item appearing again.

Meltzer-Baddeley and Baddeley tested the ability of 32 undergrads to learn Spanish vocabulary using the SuperMemo software. Crucially, they compared the learning effectiveness of two versions - one employed adaptive training, whilst the other version simply randomised the presentation of the study items. The researchers found that the adaptive training version significantly boosted performance on a vocab test given immediately after training and two weeks' later, compared with performance using the simple randomised presentation of study items.

The size of the adaptive training benefit was modest but the researchers said "in real life situations, in which motivated people may come back to material repeatedly across larger periods of times, we would expect much bigger advantages of adaptive spacing." They concluded that adaptive computer based training programmes could prove to be a useful tool "to enhance memory in healthy individuals, as well as people with learning and memory problems."
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Metzler-Baddeley, C., & Baddeley, R. (2009). Does adaptive training work? Applied Cognitive Psychology, 23 (2), 254-266 DOI: 10.1002/acp.1454

The Special Issue Spotter

We trawl the world's journals so you don't have to:

Sport & Exercise Psychology in Europe: Building on 40 years of FEPSAC - the European Federation of Sports Psychology (Psychology of Sport and Exercise).

Psychology in an economic world (Applied Psychology).

Shyness and language (Infant and Child Development).

Episodic Memory and the Brain (Neuropsychologia).

Genetics of High Cognitive Ability (Behavioural Genetics).

Walking in other people's digital shoes could back-fire

They say you should walk a mile in a person's shoes before judging them. Virtual reality technology offers this possibility by allowing us to control a digital representation of another person. Unfortunately, the first ever investigation of racial perspective-taking in an immersive virtual environment has found that assuming a different racial identity leads to increased racial bias, not less.

Victoria Groom and colleagues invited 98 participants, half of whom were of White ethnicity, to view a photograph of either a Black or White person of the same gender as themselves, and to imagine they were that person. Next the participants donned a virtual reality headset which transported them to an empty room where they were interviewed for a job, still playing the role of that other person. Crucially, half the participants could see their new identity in a mirror in the virtual room, and as they answered some introductory questions they spent at least a minute observing their adopted selves in the mirror.

After this brief immersive experience, White participants who'd assumed a new identity as a Black person, and seen their new identity in the mirror, showed increased implicit racial bias, as compared with the White participants who'd embodied the identity of a White person. Black participants too, showed increased implicit bias against Black people after embodying the virtual identity of another Black person. For the participants who didn't see their new digital selves in the virtual mirror, there were no effects on racial bias.

Implicit bias was measured using the implicit association test, which records the ease with which people associate categories (such as positive words and African American names) by assigning those categories to the same or different response keys. Explicit racial bias was measured but was unaffected by the experiment.

The finding that embodying a Black person in a virtual environment can increase racial bias may seem counter-intuitive at first, but it's possible that the effect occurred due to an established phenomenon known as "stereotype activation", in which racially-relevant stimuli can activate negative stereotypes, even if those stereotypes aren't endorsed. This would explain why the Black participants also showed increased implicit bias, and why explicit bias was unaffected in participants of both ethnicities.

"Those who have championed digital technologies as a means to render race flexible and racism obsolete maybe disheartened by these results," the researchers said. However, they cautioned that their results are far from conclusive, especially given the brevity of the immersive experience studied in this experiment.
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Groom, V., Bailenson, J., & Nass, C. (2009). The influence of racial embodiment on racial bias in immersive virtual environments. Social Influence, 1-18 DOI: 10.1080/15534510802643750

Our changing attitudes to time

Youngsters tend to live for the moment whilst older folks are more concerned about their futures. But when in a person's life does this change in perspective usually occur? A new study identifies a period between the ages of thirteen and sixteen as being critical. Laurence Steinberg and colleagues asked 935 people between the ages of ten and thirty years to answer questions regarding how much they think about the future, and to complete a time-discounting task. Briefly, this required them to make a number of hypothetical choices between less money now or more money at a later date. Choosing more money available later is a sign of being more oriented to the future.

A key difference emerged between participants who were aged thirteen and younger versus those aged sixteen and older, with the older group being more future oriented. There were no age-related differences among participants aged thirteen or less, or among participants aged sixteen or more, whilst fourteen and fifteen-year-olds were mixed, with a time orientation that did not differ from the younger or older groups.

Another important finding was that a tendency to favour immediate rewards was associated with the participants' self-reported tendency to not think about the consequences of their actions, but was less related to their self-reported impulsivity and disinclination to plan ahead. It's a subtle distinction, but Steinberg's team said this implies future orientation is influenced by at least two developmental trajectories: one relating to a proclivity to plan ahead, which continues to emerge well into early adulthood, and another related to a diminishing salience of immediate rewards, which as we've seen, undergoes a crucial change in mid-adolescence.
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Steinberg, L., Graham, S., O’Brien, L., Woolard, J., Cauffman, E., & Banich, M. (2009). Age Differences in Future Orientation and Delay Discounting. Child Development, 80 (1), 28-44 DOI: 10.1111/j.1467-8624.2008.01244.x

Do you love humanity?

"I love humanity but I hate people"

Edna St. Vincent Millay (American poet and playwright).

Psychology hasn't paid enough attention to the regard people have towards humanity - their "humanity-esteem". That's according to Michelle Luke and Gregory Maio whose new research suggests a person's view of humanity can have important social implications, for example affecting their proclivity for racism. If we think highly of humankind, it follows that we're less likely to have a negative attitude to other ethnic groups - after all, they're human too.

In an initial study, the researchers devised a new 10-item psychology questionnaire (featuring items like "On the whole I am satisfied with the evolution of humanity") and a single-item, 9-point scale version ("Overall, how favourable are you toward human beings in general?"). The researchers confirmed, with the help of hundreds of student participants, that humanity-esteem is a unidimensional construct and that it is related to, but not completely explained by, a person's feelings towards and beliefs about people, such as whether they tend to be trustworthy or not.

In further investigations, the researchers showed that people's humanity-esteem can be influenced by presenting them with images casting humankind in a positive light (e.g. a child kissing an older relative, with a strap-line celebrating the benefit of families) or in a negative light (e.g. a Palestinian man carrying a dying boy, with a strap-line blaming unrest for innocent deaths).

Moreover, increasing people's humanity-esteem with positive images was found to reduce their subsequent tendency to differentiate between groups, whilst negative images had the opposite effect. This has real-world implications, the researchers warned. "Because the media often emphasises the negative side of human nature, it may have a negative influence on humanity-esteem and increase problems of discrimination. Awareness of this potential effect should enter discussions of the ways in which events are covered." Luke and Maio end their paper with a call for more research on this topic. "Evaluations of humanity merit far more attention than they have received," they said.
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LUKE, M.L., & MAIO, G.R. (2009). Oh the humanity! Humanity-esteem and its social importance. Journal of Research in Personality, 43 (4), 586-601 DOI: 10.1016/j.jrp.2009.03.001

Unleash the crowd within

You can boost your quiz performance by unleashing the crowd within, a new study shows. The next time you're asked to estimate a historical date, for example, try doing the following: make your first estimate; then pause and assume your first guess was off the mark. Consider why, then use this new perspective to make a second estimate. Average your two estimates and, chances are, this newly calculated date will be more accurate than your original answer. The new approach is called "dialectical boot-strapping" and according to Stefan Herzog and Ralph Hertwig, it really works.

We've known since at least the time of Francis Galton that the averaged judgement of a group of independent individuals will nearly always outperform the judgement of a lone individual, no matter how expert he or she is. Galton, who was Darwin's cousin, showed this by averaging the guesses of 787 people as to the weight of an ox on show at the International Exhibition of 1884 in London. Remarkably, the crowd's averaged estimate was off by just one pound.

The wisdom of a crowd of independent-minded individuals emerges because the error in contrasting judgements is cancelled out. Imagine a jar of 100 beans. I estimate that there are 110 beans in the jar and you estimate their are 90. The errors in our judgements cancel out and together we are more accurate. Of course, real life isn't that neat, but the general principle holds, so long as our judgements are independent. If a group of individuals are not independently minded, perhaps because they're relying on the same faulty information, then collective wisdom will not emerge, because everyone's errors will all fall in the same direction.

Back to dialectical boot-strapping: Herzog and Hertwig asked 101 participants to estimate historical dates, such as the discovery of electricity. Crucially, half the participants used the dialectical boot-strapping technique. They made their first estimate, considered how it might be wrong, and then used this new perspective to make a new estimate. The other control participants simply made two best estimates.

The average of each dialectical boot-strapper's two guesses was, on average, 4.1 per cent more accurate than their initial estimate (72 per cent of them benefited by using this technique). By contrast, the average of each control participant's two estimates was, on average, just 0.3 per cent more accurate than their initial estimate.

"Part of the wisdom of the many resides in an individual mind," the researchers said. "Dialectical bootstrapping is a simple mental tool that fosters accuracy by leveraging people's capacity to construct conflicting realities."
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Herzog, S., & Hertwig, R. (2009). The Wisdom of Many in One Mind: Improving Individual Judgments With Dialectical Bootstrapping. Psychological Science, 20 (2), 231-237 DOI: 10.1111/j.1467-9280.2009.02271.x


Useful related links grabbed from the wisdom of the comments section (thanks people):

*Condorcet's jury theorem
*Two averaged guesses, without deliberate dialectical boot-strapping, can also be beneficial

Extras

Eye-catching studies that didn't make the final cut:

How much should recycling signs acknowledge the inconvenience of recycling?

Amount of attendance at religious ceremonies, but not regular prayer, is associated with people expressing greater support for suicide attacks.

Researchers create rat casino to study problem gambling.

Agreement with the statement "I felt depressed" predicts the likelihood of an older adult dying over the next five years. (hat tip: mind hacks).

Introducing the wonderfully named Jackson-5 scales.

Differences in the perceived route to happiness across 27 nations fell into three distinct categories.

Are shooting club members more aggressive than most?

After the horror of a shooting spree, it sometimes emerges in the media that the killer was a member of a shooting club. Unsurprisingly, calls often then ensue for shooting club membership to be discouraged or even banned. Two assumptions underlie such calls: first, that shooting clubs attract aggressive people to their membership, and second, that contact with guns increases aggression. Now Maria Hagtegaal and colleagues have tested whether this is true, by comparing the self-reported aggression levels and personality profiles of 59 members of Dutch shooting associations and 67 non-member, age-matched controls. Their key finding was that shooting club members are less aggressive and impulsive than controls, not more, and that most of them became a member for relaxation, or to socialise, whereas only a small minority (6 per cent) joined the club to let off steam or vent their frustration.

Obviously a major weakness of this study is its reliance on self-report. But the researchers recognised this and included a measure of "social desirability" - the tendency for participants to answer in a way that casts them in the best possible light. The social desirability measure included impossibly good items like, "Are all your habits good and desirable ones?". Strong agreement with such statements indicates dishonest answering. The shooting club members displayed more social desirability than the controls, but crucially, their lower aggression and impulsivity remained even after adjustment for their higher social desirability.
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Nagtegaal, M., Rassin, E., & Muris, P. (2009). Do members of shooting associations display higher levels of aggression? Psychology, Crime & Law, 15 (4), 313-325 DOI: 10.1080/10683160802241682