Rather than being fixed over our lifespan, a person’s IQ can show both significant increases and decreases during their teenage years, new results suggest.

Reported in Nature today, the results reveal that verbal and non-verbal ability, as measured by IQ (Intelligence Quotient) tests, fluctuated over a period of three to four years during adolescence. They also showed that these changes correspond to specific structural changes in brain regions associated with speech and movement.

{ Cosmos | Continue reading }

We investigated the relationship between creativity, personality, latent inhibition (LI), and psychopathology.

The results suggest that actors and polydrug dependents can be characterized by (a) high scores in the personality dimension psychoticism, (b) high originality during creative idea generation, and (c) decreased LI as compared with the other groups. Correlational analyses moreover revealed significant associations between LI, originality, and psychoticism.

According to our findings, creative people and people suffering from mental disorders appear to share some common personality and cognitive traits.

{ APA PsychNET | Continue reading }

A Waboba is a ball that bounces on water (wa-ter bo-uncing ba-ll). That makes it kind of unusual since a simple experiment will show that many balls do not bounce on water. And that raises an interesting question–how does the Waboba work?

Today we get an answer from Michael Wright at Brigham Young University in Utah and a few buddies. These guys videoed the way three balls interact with water when bounced.

A Superball, which is solid and so has a relatively small surface area for its mass, burrows deep into the water, even when it hits at a shallow angle. So it does not bounce.

A raquet ball, on the other hand,is hollow and so has a larger surface area ratio to mass ratio. When thrown at a shallow angle, it penetrates only a small distance into the water creating a depression in the surface through which it planes back onto the surface. So it rebounds a little.

The Waboba is hollow but it is also soft. (…) Because it is soft, the ball flattens into disc-shape when it hits the surface and this allows it to aquaplane efficiently across the surface. (…)

Why might this be useful? Wright and co don’t say in their video but the fact that one of the team is with the Naval Undersea Warfare Center in Newport might offer a clue.

{ The Physics arXiv Blog | Continue reading }

artwork { Ellsworth Kelly, Yellow White, 1961 }

The idea of the ‘hot hand’, where a player who makes several successful shots has a higher chance of making some more, is popular with sports fans and team coaches, but has long been considered a classic example of a cognitive fallacy – an illusion of a ‘streak’ caused by our misinterpretation of naturally varying scoring patterns.

But a new study has hard data to show the hot hand really exists and may turn one of the most widely cited ‘cognitive illusions’ on its head.

{ Mind Hacks | Continue reading }

related { Why do some athletes choke under pressure? }

{ United Academics | Continue reading }

If one could rewind the history of life, would the same species appear with the same sets of traits? Many biologists have argued that evolution depends on too many chance events to be repeatable. But a new study investigating evolution in three groups of microscopic worms, including the strain that survived the 2003 Columbia space shuttle crash, indicates otherwise. When raised in a lab under crowded conditions, all three underwent the same shift in their development by losing basically the same gene. The work suggests that, to some degree, evolution is predictable.

{ Nature | Continue reading }

images { Jesse Richards | Susan Rothenberg }

{ A Mystery: Why Can’t We Walk Straight? }

“When you sell a stock,” I asked him, “who buys it?” He answered with a wave in the vague direction of the window, indicating that he expected the buyer to be someone else very much like him. That was odd: because most buyers and sellers know that they have the same information as one another, what made one person buy and the other sell? Buyers think the price is too low and likely to rise; sellers think the price is high and likely to drop. The puzzle is why buyers and sellers alike think that the current price is wrong. (…)

In a paper titled “Trading Is Hazardous to Your Wealth,” Odean and his colleague Brad Barber showed that, on average, the most active traders had the poorest results, while those who traded the least earned the highest returns. (…)

Individual investors like to lock in their gains; they sell “winners,” stocks whose prices have gone up, and they hang on to their losers. Unfortunately for them, in the short run going forward recent winners tend to do better than recent losers, so individuals sell the wrong stocks. They also buy the wrong stocks. Individual investors predictably flock to stocks in companies that are in the news. Professional investors are more selective in responding to news. These findings provide some justification for the label of “smart money” that finance professionals apply to themselves.

Although professionals are able to extract a considerable amount of wealth from amateurs, few stock pickers, if any, have the skill needed to beat the market consistently, year after year. (…) At least two out of every three mutual funds underperform the overall market in any given year.

{ NY Times | Continue reading }

Jealousy has often been considered a dangerous emotion because it motivates a wide range of behavior including spousal violence and abuse. It is therefore a major task of jealousy research to identify potential determinants of jealousy-motivated behavior. One such potential determinant is the intensity of the jealousy feeling. It appears reasonable to assume that mild jealousy feelings promote rather innocuous mate retention tactics such as heightened vigilance. In contrast, very intense feelings are more likely to evoke ferocious reactions including violence and abuse.

Several determinants of jealousy intensity have been identified. First, sneaking suspicions of a partner’s infidelity appear to result in mild, anxious-insecurity like jealousy feelings, whereas the certainty of actual infidelity is associated with intense, rage-like jealousy feelings.

Secondly, based on evolutionary psychological considerations, Buunk and his colleagues provided substantial empirical evidence that rival characteristics affect jealousy intensity. These authors found that a (potential) rival’s high physical attractiveness elicits more jealousy in women than in men. In contrast, a (potential) rival high in social and physical dominance and social status evokes more jealousy in men than in women.

Third, a fundamental factor contributing to the intensity of jealousy concerns the infidelity type the partner engages in. Empirical evidence continues to accumulate confirming the evolutionary psychological hypothesis that men respond with more intense jealousy than women to a mate’s sexual infidelity whereas, conversely, women respond with more intense jealousy than men to a mate’s emotional infidelity.

As the unfaithful partner most likely tries to conceal his or her infidelity, the jealousy mechanism often needs to rely on indirect evidence from which a mate’s infidelity can be inferred. An important source of such indirect evidence consists of sudden and conspicuous changes in the partner’s behavior. (…) However, the sudden and conspicuous changes in the partner’s behavior as factors contributing to jealousy intensity and thus determinants of jealousy-motivated behavior have several limitations. First, these behavioral changes are often ambiguous with respect to the infidelity type (e.g., the clothing style suddenly changes; he or she stops returning your phone calls), thus presumably requiring complex inference processes that are prone to errors. Second, some if not most of these behavioral cues to infidelity were certainly not available during our ancestors’ past, (e.g., the clothing style suddenly changes; he or she stops returning your phone calls). As a consequence, they could not have shaped the jealousy mechanism during its evolutionary history. (…)

These considerations raise the question whether there are possible additional cues to infidelity that do not suffer from the limitations mentioned above. The present study picks up this question and examines a hitherto neglected but fundamental proximate contextual factor in jealousy research: The spatial distance between the persons involved in the “eternal triangle” (Buss, 2000), that is the partner, the potential rival and the jealous person. Spatial distance between the three persons (a) was recurrently available to our ancestors and thus could have been exploited by the jealousy mechanism throughout our evolutionary past, (b) can be clearly detected, (c) is not ambiguous and thus does not require complex inferential processes, (d) informs rather directly about appropriate mate guarding behavior (e.g., moving closer to the partner; increasing the distance between the partner and the potential rival or stepping between the partner and the potential rival).

{ Evolutionary Psychology | Continue reading | PDF }

painting { Fragonard, The Stolen Kiss, c. 1786-1788 }

{ “Best abstract ever.” The lead author, Michael Berry, was awarded the 2000 Ig Nobel Prize in physics for using magnets to levitate a frog. }

In theory, the relationship between rainfall and tree cover should be straightforward: The more rain a place has, the more trees that will grow there. But small studies have suggested that changes can occur in discrete steps. Add more rain to a grassy savanna, and it stays a savanna with the same percentage of tree cover for quite some time. Then, at some crucial amount of extra rainfall, the savanna suddenly switches to a full-fledged forest.

But no one knew whether such rapid transformations happened on a global scale. (…) Holmgren’s group identified three distinct ecosystem types: forest, savanna, and a treeless state. Forests typically had 80 percent tree cover, while savannas had 20 percent trees and the “treeless” about 5 percent or less. Intermediate states — with, say, 60 percent tree cover — are extremely rare, Holmgren says. Which category a particular landscape fell into depended heavily on rainfall.

Fire may be another important factor in determining tree cover.

{ ScienceNews | Continue reading }

painting { Albert Bierstadt, Giant Redwood Trees of California, 1874 }

In 2006, two researchers – Janine Willis and Alexander Todorov – demonstrated that it only takes 1/10th of a second to form an impression of attractiveness, trustworthiness, competence and aggressiveness. Quite frighteningly, more time doesn’t make a difference – that 1/10th of a second’s impression merely becomes further cemented over the course of the first second.

And in fact, 100ms may be being generous – the same year Bar et al. demonstrated that consistent first impressions were made after 39ms. However, this latter study showed an opportunity for us to breathe a sigh of relief: impressions are not consistent on intelligence: because unlike attractiveness, trustworthiness, competence and aggressiveness, there is no short-term affect on survival from intelligence.

{ Setsights Training | Continue reading }

photo { Erica Segovia }

The life cycle of the parasite Toxoplasma gondii goes like this: Toxoplasma reproduces inside the intestine of a cat, which sheds the parasite in its feces. Rats then ingest the parasite when they consume food or water contaminated with cat feces. The parasite takes up residence in the rat’s brain and, once the rat gets eaten by a cat, it starts the cycle all over again.

Researchers have known for a few years that a rat infected with Toxoplasma loses its natural response to cat urine and no longer fears the smell. And they know that the parasite settles in the rat’s amygdala, the part of the brain that processes fear and emotions. Now a new study in the journal PLoS ONE adds another bizarre piece to the tale: When male rats infected with Toxoplasma smell cat urine, they have altered activity in the fear part of the brain as well as increased activity in the part of the brain that is responsible for sexual behavior and normally activates after exposure to a female rat.

The double messages of “you smell a cat but he’s not dangerous” and “that cat is a potential mate” lure the rat into the kitty’s deadly territory, just what the parasite needs to reproduce.

{ Smithsonia magazine | Continue reading }

{ With brain donation, unlike other types of organ donation, it’s important to have information about the donor and their mental functioning during life. | NewScientist | full story }

Three pathways to disinhibition:

• Social Power: Powerful people are used to relative abundance and have an increased inclination to pursue potential rewards. Because the experience of power increases a “goal and reward focus,” individuals feel less restrained in expressing their current motives – regardless of the social implications.

• Intoxication: Consuming too much alcohol decreases cognitive resources, and only the most prominent cues will guide behavior in this state. Thus, pre-existing attitudes and personality traits may be expressed more freely, such as aggressive tendencies or risky sexual decision-making. At the same time, however, inebriated individuals tend to be more helpful than sober counterparts when the situation calls for heroism.

• Anonymity: A cloaked identity serves to reduce social desirability concerns and external constraints on action. As such, an individual may be less inclined to maintain usual levels of social acceptance. This could result in higher levels of honesty and self-disclosure – or heightened aggression and verbal abuse – in an anonymous chatroom.

Each of these processes - a reward focus, cognitive exhaustion, and lack of social concerns - block the same neurological system - the Behavioral Inhibition System - that regulates behavior. The combination of these forces (e.g., a powerful person who has been imbibing all night and then goes into an anonymous chat room) is likely to produce the most disinhibition.

{ EurekAlert | Continue reading }

related { When the economy is down, alcohol consumption goes up }

photo { Craig Mammano }

{ Why Humans Have Sex | Why Women Have Sex }

images { 1. Don Oehl | 2. Helmut Newton }

The genius behind the square tree was Robert Falls, who in the late 1980s was a PhD candidate in the U. of B.C. botany department. Falls noticed that some tree trunks exposed to high winds had become less round in cross section — they’d grown thicker on their leeward and windward sides to buttress themselves. Falls theorized that flexing of the bark by the wind encouraged the cambium— the layer of growth cells just beneath the bark — to produce extra wood. To test his theory, Falls subjected trees to what he thought might be comparable stress by scarring them with surgical tools. Sure enough, more wood grew at the site of the scars.

Hearing the news, a professor in the university’s wood science department suggested Falls try using this discovery to grow trees with a square cross section. Square trees would be a boon to the lumber industry. Since boards are flat and trees are round, only 55 to 60 percent of the average log can be sawed into lumber — the rest winds up getting turned into paper pulp and the like, or just gets thrown away. So Falls obligingly scarred seedlings of several species (western redcedar, black cottonwood, and redwood) at 90-degree intervals around their trunks. The trees responded as hoped, becoming “unmistakably squarish,” he tells me. (…)

Square trees were just the start. In 1989 Falls was awarded a Canadian patent for an “Expanded Wood Growing Process,” a bland title that fails to capture the revolutionary nature of the concept. Square trees by comparison are a mere novelty. The young scientist had come up with a way to grow boards.

{ The Straight Dope | Continue reading }

image { Bo Young Jung & Emmanuel Wolfs, Square Tree Trunk stool II, 2009 | bronze }

{ Balls in boxes offer a simple system for studying geometry across a series of spatial dimensions. A ball is the solid object bounded by a sphere; the boxes are cubes with sides of length 2, which makes them just large enough to accommodate a ball of radius 1. In one dimension (top left) the ball and the cube have the same shape: a line segment of length 2. In two dimensions (top right) and three dimensions (bottom) the ball and cube are more recognizable. As dimension increases, the ball fills a smaller and smaller fraction of the cube’s internal volume. In three dimensions the filled fraction is about half; in 100-dimensional space, the ball has all but vanished, filling only 1.8 × 10^–70 of the cube’s volume. | An Adventure in the Nth Dimension | American Scientist | full story }

If you ask a person when “middle age” begins, the answer, not surprisingly, depends on the age of that respondent. American college-aged students are convinced that one fits soundly into the middle-age category at 35. For respondents who are actually 35, middle age is half a decade away, with 40 representing the inaugural year. (…) Recently, a large sample of Swiss participants spanning several generations agreed with one another that middle-aged people are those who are between 35 to 53 years of age.

However, the precise chronological point at which we formally enter “middle age” is of little importance. (…) We’ve all heard of the dreaded “midlife crisis,” but what, exactly, is it? Furthermore, does it even exist as a scientifically valid concept? (…)

“Midlife crisis” was coined by Elliott Jacques in 1965. (…) According to him, the midlife crisis is such a crisis that many great artists and thinkers don’t even survive it. (…) He decided to crunch the numbers with a “random sample” of 310 such geniuses and, indeed, he discovered that a considerable number of these formidable talents—including Mozart, Raphael, Chopin, Rimbaud, Purcell, and Baudelaire—succumbed to some kind of tragic fate or another and drew their last breaths between the ages of 35 and 39. “The closer one keeps to genius in the sample,” Jacques observes, “the more striking and clear-cut is this spiking of the death rate in midlife.” (…)

Basically, argues Jacques, around the age of 35, genius can go in one of three directions. If you’re like that last batch of folks, you either die, literally, or else you perish metaphorically, having exhausted your potential early on in a sort of frenzied, magnificent chaos, unable to create anything approximating your former genius. The second type of individual, however, actually requires the anxieties of middle age—specifically, the acute awareness that one’s life is, at least, already half over—to reach their full creative potential. (…) Finally, the third type of creative genius is prolific and accomplished even in their earlier years, but their aesthetic or style changes dramatically at middle age, usually for the better. (…)

The phrase “midlife crisis” didn’t really creep into suburban vernacular as a catchall diagnosis until the late 1970s. This is when Yale’s Daniel Levinson, building on the stage theory tradition of lifespan developmentalist Erik Erikson, began popularizing tales of middle-class, middle-aged men who were struggling with transitioning to a time where “one is no longer young and yet not quite old.”

{ Scientific American | Continue reading }

When scientists delve into studies of the co-evolution of plants and their pollinators, they have something of a chicken/egg problem—which evolved first, the plant or its pollinator? Orchids and orchid bees are a classic example of this relationship. The flowers depend on the bees to pollinate them so they can reproduce and, in return, the bees get fragrance compounds they use during courtship displays (rather like cologne to attract the lady bees). And researchers had thought that they co-evolved, each species changing a bit, back and forth, over time.

But a new study in Science has found that the relationship isn’t as equal as had been thought. The biologists reconstructed the complex evolutionary history of the plants and their pollinators, figuring out which bees pollinated which orchid species and analyzing the compounds collected by the bees. It seems that the orchids need the bees more than the bees need the flowers—the compounds produced by the orchids are only about 10 percent of the compounds collected by the bees. The bees collect far more of their “cologne” from other sources, such as tree resin, fungi and leaves.

{ Smithsonian Magazine | Continue reading }

sculpture { Edgar Orlaineta }