Past research showed that people accumulate more knowledge about other people and objects they like compared to those they dislike. More knowledge is commonly assumed to lead to more differentiated mental representations; therefore, people should perceive others they like as less similar to one another than others they dislike.

We predict the opposite outcome based on the density hypothesis; accordingly, positive impressions are less diverse than negative impressions as there are only a few ways to be liked but many ways to be disliked. Therefore, people should perceive liked others as more similar to one another than disliked others even though they have more knowledge about liked others.

Seven experiments confirm this counterintuitive prediction and show a strong association between liking and perceived similarity in person perception.

{ Journal of Experimental Social Psychology | Continue reading }

What happens to us as we accrue knowledge and experience, as we become experts in a field? Competence follows. Effortlessness follows. But certain downsides can follow too. We reported recently on how experts are vulnerable to an overclaiming error – falsely feeling familiar with things that seem true of a domain but aren’t. Now a new paper in the Journal of Experimental Social Psychology explores how feelings of expertise can lead us to be more dogmatic towards new ideas.

{ BPS | Continue reading }

In Experiment 1 (N = 218), where female participants rated male facial attractiveness, the facilitative effect of smiling was present when judging long-term partners but absent for short-term partners. This pattern was observed for East Asians as well as for Europeans. […]

Related to this issue, Morrison et al. (2013) compared the attractiveness of faces displaying the six basic emotions (anger, disgust, fear, happiness, sadness, and surprise). Faces with a happy expression were rated to be more attractive than faces with the other emotions, but they were rated as attractive as neutral ones.

{ Evolutionary Psychology | Continue reading }

related { Transferring the expressions of one person’s face to the other in realtime }

This research examines the role of alcohol consumption on self-perceived attractiveness. Study 1, carried out in a barroom (N= 19), showed that the more alcoholic drinks customers consumed, the more attractive they thought they were.

In Study 2, 94 non-student participants in a bogus taste-test study were given either an alcoholic beverage (target BAL [blood alcohol level]= 0.10 g/100 ml) or a non-alcoholic beverage, with half of each group believing they had consumed alcohol and half believing they had not (balanced placebo design). After consuming beverages, they delivered a speech and rated how attractive, bright, original, and funny they thought they were. The speeches were videotaped and rated by 22 independent judges. Results showed that participants who thought they had consumed alcohol gave themselves more positive self-evaluations. However, ratings from independent judges showed that this boost in self-evaluation was unrelated to actual performance.

{ British Journal of Psychology | PDF }

Starting at age 55, our hippocampus, a brain region critical to memory, shrinks 1 to 2 percent every year, to say nothing of the fact that one in nine people age 65 and older has Alzheimer’s disease. The number afflicted is expected to grow rapidly as the baby boom generation ages. Given these grim statistics, it’s no wonder that Americans are a captive market for anything, from supposed smart drugs and supplements to brain training, that promises to boost normal mental functioning or to stem its all-too-common decline. […]

A few years back, a joint study by BBC and Cambridge University neuroscientists put brain training to the test. Their question was this: Do brain gymnastics actually make you smarter, or do they just make you better at doing a specific task? […] All subjects took a benchmark cognitive test, a kind of modified I.Q. test, at the beginning and at the end of the study. Although improvements were observed in every cognitive task that was practiced, there was no evidence that brain training made people smarter.

There was, however a glimmer of hope for subjects age 60 and above. Unlike the younger participants, older subjects showed a significant improvement in verbal reasoning, one of the components of the benchmark test, after just six weeks of brain training, so the older subjects continued in a follow-up study for a full 12 months.

Results of this follow-up study, soon to be published in a peer-reviewed journal, generally show that continued brain training helps older subjects maintain the improvement in verbal reasoning seen in the earlier study. This is good news because it suggests that brain exercise might delay some of the effects of aging on the brain.

{ NY Times | Continue reading }

Experts say fakes have become one of the most vexing problems in the art market. […]

Two years ago, the center, known for its work in bioengineering, encryption and nanotechnology, set about developing a way to infuse paintings, sculptures and other artworks with complex molecules of DNA created in the lab. […]

The new approach, in its formative stage, would implant synthetic DNA, not the personal DNA of the artists, because of privacy issues and because a person’s DNA could conceivably be stolen and embedded, thus undermining the authority of such a marking protocol.

The developers said the bioengineered DNA would be unique to each item and provide an encrypted link between the art and a database that would hold the consensus of authoritative information about the work. The DNA details could be read by a scanner available to anyone in the art industry wanting to verify an object.

{ NY Times | Continue reading }

installation { Yayoi Kusama, The obliteration room, 2002-present }

Statisticians love to develop multiple ways of testing the same thing. If I want to decide whether two groups of people have significantly different IQs, I can run a t-test or a rank sum test or a bootstrap or a regression. You can argue about which of these is most appropriate, but I basically think that if the effect is really statistically significant and large enough to matter, it should emerge regardless of which test you use, as long as the test is reasonable and your sample isn’t tiny. An effect that appears when you use a parametric test but not a nonparametric test is probably not worth writing home about.

A similar lesson applies, I think, to first dates. When you’re attracted to someone, you overanalyze everything you say, spend extra time trying to look attractive, etc. But if your mutual attraction is really statistically significant and large enough to matter, it should emerge regardless of the exact circumstances of a single evening. If the shirt you wear can fundamentally alter whether someone is attracted to you, you probably shouldn’t be life partners. […]

In statistical terms, a glance at across a bar doesn’t give you a lot of data and increases the probability you’ll make an incorrect decision. As a statistician, I prefer not to work with small datasets, and similarly, I’ve never liked romantic environments that give me very little data about a person. (Don’t get me started on Tinder. The only thing I can think when I see some stranger staring at me out of a phone is, “My errorbars are huge!” which makes it very hard to assess attraction.) […]

I think there’s even an argument for being deliberately unattractive to your date, on the grounds that if they still like you, they must really like you.

{ Obsession with Regression | Continue reading }

Neurotechnologies are “dual-use” tools, which means that in addition to being employed in medical problem-solving, they could also be applied (or misapplied) for military purposes.

The same brain-scanning machines meant to diagnose Alzheimer’s disease or autism could potentially read someone’s private thoughts. Computer systems attached to brain tissue that allow paralyzed patients to control robotic appendages with thought alone could also be used by a state to direct bionic soldiers or pilot aircraft. And devices designed to aid a deteriorating mind could alternatively be used to implant new memories, or to extinguish existing ones, in allies and enemies alike. […]

In 2005, a team of scientists announced that it had successfully read a human’s mind using functional magnetic resonance imaging (fMRI), a technique that measures blood flow triggered by brain activity. A research subject, lying still in a full-body scanner, observed a small screen that projected simple visual stimuli—a random sequence of lines oriented in different directions, some vertical, some horizontal, and some diagonal. Each line’s orientation provoked a slightly different flurry of brain functions. Ultimately, just by looking at that activity, the researchers could determine what kind of line the subject was viewing.

It took only six years for this brain-decoding technology to be spectacularly extended—with a touch of Silicon Valley flavor—in a series of experiments at the University of California, Berkeley. In a 2011 study, subjects were asked to watch Hollywood movie trailers inside an fMRI tube; researchers used data drawn from fluxing brain responses to build decoding algorithms unique to each subject. Then, they recorded neural activity as the subjects watched various new film scenes—for instance, a clip in which Steve Martin walks across a room. With each subject’s algorithm, the researchers were later able to reconstruct this very scene based on brain activity alone. The eerie results are not photo-
realistic, but impressionistic: a blurry Steve Martin floats across a surreal, shifting background.

Based on these outcomes, Thomas Naselaris, a neuroscientist at the Medical University of South Carolina and a coauthor of the 2011 study, says, “The potential to do something like mind reading is going to be available sooner rather than later.” More to the point, “It’s going to be possible within our lifetimes.”

{ Foreign Policy | Continue reading }

A recent Norwegian study shows that men and women react differently to various types of infidelity. Whereas men are most jealous of sexual infidelity, so-called emotional infidelity is what makes women the most jealous. Evolutionary psychology may help explain why this may be. […]

Men and women over thousands of generations have had to adapt to different challenges that are related to reproduction. Infidelity is one such challenge. A man must decide whether he really is the father of his partner’s child, and if he should choose to invest all his protection and status resources on this child. Since the dawn of time men have grappled with paternity insecurity, since fertilization occurs inside a woman’s body.

According to the evolutionary psychology explanation, men’s jealousy is an emotional reaction to signs of sexual infidelity. The jealousy serves to reduce the chances that his partner is cheating, since he then monitors her more closely.

It’s a different story for the child’s mother. She knows for sure that she is the child’s mother, but she must ensure that the child’s father will provide their offspring with food and the security and social status it needs. The greatest threat for the woman is not that the man has sex with other women, but that he spends time and resources on women other than her.

{ Medical Xpress | Continue reading }

Imagine that you are imprisoned in a tunnel that opens out onto a precipice two paces to your left, and a pit of vipers two paces to your right. To torment you, your evil captor forces you to take a series of steps to the left and right. You need to devise a series that will allow you to avoid the hazards — if you take a step to the right, for example, you’ll want your second step to be to the left, to avoid falling off the cliff. You might try alternating right and left steps, but here’s the catch: You have to list your planned steps ahead of time, and your captor might have you take every second step on your list (starting at the second step), or every third step (starting at the third), or some other skip-counting sequence. Is there a list of steps that will keep you alive, no matter what sequence your captor chooses?

In this brainteaser, devised by the mathematics popularizer James Grime, you can plan a list of 11 steps that protects you from death. But if you try to add a 12th step, you are doomed: Your captor will inevitably be able to find some skip-counting sequence that will plunge you over the cliff or into the viper pit.

Around 1932, Erdős asked, in essence, what if the precipice and pit of vipers are three paces away instead of two? What if they are N paces away? Can you escape death for an infinite number of steps? The answer, Erdős conjectured, was no — no matter how far away the precipice and viper pit are, you can’t elude them forever.

But for more than 80 years, mathematicians made no progress on proving Erdős’ discrepancy conjecture (so named because the distance from the center of the tunnel is known as the discrepancy).

{ Quanta | Continue reading }

We review recent evidence revealing that the mere willingness to engage analytic reasoning as a means to override intuitive “gut feelings” is a meaningful predictor of key psychological outcomes in diverse areas of everyday life. For example, those with a more analytic thinking style are more skeptical about religious, paranormal, and conspiratorial concepts. In addition, analytic thinking relates to having less traditional moral values, making less emotional or disgust-based moral judgments, and being less cooperative and more rationally self-interested in social dilemmas. Analytic thinkers are even less likely to offload thinking to smartphone technology and may be more creative.

{ SSRN | Continue reading }

oil on canvas { Alberto Giacometti, Portrait of Pierre Josse, 1961 }

My brain tumor introduced itself to me on a grainy MRI, in the summer of 2009, when I was 28 years old. […]

Over time I would lose my memory—almost completely—of things that happened just moments before, and become unable to recall events that happened days and years earlier. […]

Through persistence, luck, and maybe something more, an incredible medical procedure returned my mind and memories to me almost all at once. I became the man who remembered events I had never experienced, due to my amnesia. The man who forgot which member of his family had died while he was sick, only to have that memory, like hundreds of others, come flooding back. The memories came back out of order, with flashbacks mystically presenting themselves in ways that left me both excited and frightened.

{ Quartz | Continue reading }

People with a certain type of gene are more deeply affected by their life experiences, a new study has revealed.

The findings challenge traditional thinking about depression, showing what might be considered a risk gene for depression in one context, may actually be beneficial in another.

Researchers at the University of Melbourne were interested in why some, but not all adults who have experienced sexual or physical abuse as children go on to develop long-term depression. […]

Those with the s/s genotype (23%) who had experienced sexual or physical abuse as a child were more likely to experience ongoing severe depressive symptoms in middle age. But, conversely, those with this same genotype but no history of abuse were happier than the rest of the population.

{ EurekAlert | Continue reading }

An influential theory about the malleability of memory comes under scrutiny in a new paper in the Journal of Neuroscience.

The ‘reconsolidation’ hypothesis holds that when a memory is recalled, its molecular trace in the brain becomes plastic. On this view, a reactivated memory has to be ‘saved’ or consolidated all over again in order for it to be stored.

A drug that blocks memory formation (‘amnestic’) will, therefore, not just block new memories but will also cause reactivated memories to be forgotten, by preventing reconsolidation.

This theory has generated a great deal of research interest and has led to speculation that blocking reconsolidation could be used as a tool to ‘wipe’ human memories.

However, Gisquet-Verrier et al. propose that amnestic drugs don’t in fact block reconsolidation, but instead add an additional element to a reactivated memory trace. This additional element is a memory of the amnestic itself – essentially, ‘how it feels’ to be intoxicated with that drug.

In other words, the proposal is that amnestics tag memories with ‘amnestic-intoxication’ which makes these memories less accessible due to the phenomenon of state dependent recall. This predicts that the memories could be retrieved by giving another dose of the amnestic.

So, Gisquet-Verrier et al. are saying that (sometimes) an ‘amnestic’ drug can actually improve memory.

{ Neuroskeptic | Continue reading }

related { Kids can remember tomorrow what they forgot today }

Sensitive new telescopes now permit astronomers to detect the waste heat that is expected to be a signature of advanced alien civilisations that can harness enormous energies on the scale of the stellar output of their own galaxy. Professor Michael Garrett has used radio observations of candidate galaxies to show that such advanced civilisations are very rare or entirely absent from the local Universe.

{ Astron | Continue reading }

Health has been identified as an important variable involved in mate choice. Unhealthy organisms are generally less able to provide reproductively important resources to partners and offspring and are more likely to pass on communicable disease.

Research on human mate preferences has shown that both men and women prefer healthy mates. Yet to date, little research has examined how health relates to one’s own mating experiences. In the present study, 164 participants (87 women) who were currently in heterosexual romantic relationships completed measures of frequency and severity of health problems, anticipated partner infidelity, and intensity of jealousy felt in their current relationship. […]

[I]ndividuals who believe they are in poor health are also likely to perceive themselves to be at a mating disadvantage. Results indicated that self-reported poor health, in terms of both frequency and severity of health symptoms, predicted a greater perception that one’s partner would commit an infidelity as well as increased romantic jealousy. Anticipated partner infidelity mediated the links between health problems and jealousy, suggesting that unhealthy individuals perceive their partners as being more likely to mate with an intrasexual (same-sex) rival, in turn facilitating jealousy.

{ Evolutionary Psychology | PDF }

The ratio between the body circumference at the waist and the hips (or WHR) is a secondary sexual trait that is unique to humans and is well known to influence men’s mate preferences. Because a woman’s WHR also provides information about her age, health and fertility, men’s preference concerning this physical feature may possibly be a cognitive adaptation selected in the human lineage. […]

We analyzed the WHR of women considered as ideally beautiful who were depicted in western artworks from 500 BCE to the present. These vestiges of the past feminine ideal were then compared to more recent symbols of beauty: Playboy models and winners of several Miss pageants from 1920 to 2014. We found that the ideal WHR has changed over time in western societies: it was constant during almost a millennium in antiquity (from 500 BCE to 400 CE) and has decreased from the 15th century to the present. Then, based on Playboy models and Miss pageants winners, this decrease appears to slow down or even reverse during the second half of the 20th century.

The universality of an ideal WHR is thus challenged, and historical changes in western societies could have caused these variations in men’s preferences.

{ PLOS | Continue reading }

A new study from Duke University finds that adolescents ages 10 to 16 can be more analytical in their economic choices than many slightly older young adults. […]

Scott Huettel, a professor of psychology and neuroscience at Duke: “The new results point to the idea that we should not think of adolescents as being irrational. What’s different about them is they don’t use simple rules as effectively.”

Such simple rules are the mental shortcuts people take in decision-making—often to their benefit—as they age and gain more experience. Most adults apply the “don’t drink and drive” rule, for example, to avoid getting in a car with someone who’s been drinking. In contrast, teens may more carefully weigh this decision.

“Adolescents are going to be more likely to use cost-benefit analysis than the (simple rules) that adults use.” […]

Other research has shown that adolescents aren’t necessarily more risk-seeking but that they are more sensitive to good outcomes compared with adults.

{ Science Beta | Continue reading }

photo { Vasantha Yogananthan }

In daily life, we frequently encounter false claims in the form of consumer advertisements, political propaganda, and rumors. Repetition may be one way that insidious misconceptions, such as the belief that vitamin C prevents the common cold, enter our knowledge base. Research on the illusory truth effect demonstrates that repeated statements are easier to process, and subsequently perceived to be more truthful, than new statements.

The prevailing assumption in the literature has been that knowledge constrains this effect (i.e., repeating the statement “The Atlantic Ocean is the largest ocean on Earth” will not make you believe it). We tested this assumption. […]

Contrary to prior suppositions, illusory truth effects occurred even when participants knew better. […] Participants demonstrated knowledge neglect, or the failure to rely on stored knowledge, in the face of fluent processing experiences.

{ Journal of Experimental Psychology | Continue reading }

Animals eject fluids for waste elimination, communication, and defense from predators. These diverse systems all rely on the fundamental principles of fluid mechanics, which we use to predict urination duration across a wide range of mammals. […]

Using high-speed videography and flow-rate measurement obtained at Zoo Atlanta, we discover that all mammals above 3 kg in weight empty their bladders over nearly constant duration of 21 s. […]

Smaller mammals are challenged during urination by high viscous and capillary forces that limit their urine to single drops.

{ PNAS | Continue reading }

collage { imp kerr }