evidence tDCS worksStudies showing that tDCS works continue to pour in. A new study from Vanderbilt University is the latest to suggest that transcranial direct-current stimulation does in fact boost our cognitive skills. Although their press release somewhat misleadingly refers to tDCS as an “electric thinking cap“), it can affect our ability to learn, and “this effect can be enhanced or depressed depending on the direction of the current.”

Their study looked at the brain’s response to mistakes, and whether this response could be manipulated using a mild electrical current (in this case tDCS). Subjects were given a 20-minute session of electrical of stimulation, followed by a learning task that resembles Simon Says: using trial and error, the subjects had to figure out which buttons on a game controller corresponded to specific colors displayed on a monitor. Subjects who were given the tDCS stimulation “made fewer errors and learned from their mistakes more quickly than they did after the sham stimulus.”

The improvements in error rates were small, only about 4 percent, but the study’s co-author Geoffrey Woodman said that “this success rate is far better than that observed in studies of pharmaceuticals or other types of psychological therapy.” Likewise, the effects of the 20-minute stimulation session did indeed transfer to other tasks, and lasted for about five hours.



guess iq from photoA new study in PLOS shows that men and women can accurately guess the IQ of men by viewing facial photographs (40 of men, 40 of women). Curiously, no relationship between perceived intelligence and IQ was found for women; “the strong halo effect of attractiveness,” the authors write, might “prevent an accurate assessment of the intelligence of women.”

The study’s participants felt that “highly intelligent” faces are prolonged, with a broader distance between the eyes, a larger nose, a slight upturn to the corners of the mouth, and a sharper, pointing, less rounded chin. Yet there was no actual correlation found between facial shape and intelligence. So whatever it is that allows both men and women to accurately gauge men’s intelligence based on photographs of their faces remains inexplicable; the authors speculate that it might be gaze, eye color, or even or skin texture.

“Our data suggest that a clear mental image how a smart face should look does exist for both men and women,” according to the study. “The ‘high intelligence’ faces appear to be smiling more than the ‘low intelligence’ faces.” Likewise, “perceived intelligence correlates with perceived trustworthiness and happiness. Conversely, low-intelligence faces are perceived as untrustworthy and considered angrier.”


thyroid-brain-iq-dnaA new study featured by the BBC shows that young people with a common gene variation (Thr92Ala), combined with lower thyroid hormone levels, were four times more likely to have an IQ under 85. This combination occurs in about 4% of the UK population.

As the study’s lead author Peter Taylor of Cardiff University pointed out, there may be benefit in carrying out a test for this gene variant to identify children who are at the greatest risk of developing low IQ. This also “raises the possibility that children at risk could be treated with standard thyroid hormone tablets to compensate for impaired thyroid hormone processing.”

According to the BBC, these findings could be a step towards introducing neonatal screening to help identify children at risk, who could then be treated with standard thyroid tablets.

Oxford professor Julian Savulescu has responded enthusiastically to the findings in an article entitled “Genetic screening to enhance IQ should be embraced” (also re-posted at Discover), in which he points out the difficulties faced by those with IQs in the 70-85 range: fewer job opportunities, and an increased risk of living in poverty or being in prison.

“So it is clear that the low-normal intelligence, although not classified as disabled, are significantly disadvantaged. If we could enhance their intelligence, say with thyroid hormone supplementation, we should.”

He stresses that this new research is only indicative, not conclusive, and that genetic screening is no guarantee of a healthy or smart child.

“While medical treatments are important, how bad any condition turns out being depends on many other factors as well. For example, if those at risk of having a low-normal IQ were identified early, enhanced education or diet or other non-medical environmental modifications could be employed.”

“All we can do in life is try to reduce the chances of bad things happening, and increase the chances of good things happening. That includes using genetic information.”


happiness-iqDoes being smart make you happy? Research into intelligence and happiness has not generally shown a strong correlation between the two. As Bostrom/Sandberg wrote in 2009, “There is no link between higher intelligence and more happiness,” and Gottfredson said much the same thing in 2004: “subjective well-being (happiness) … is regularly found not to correlate meaningfully with IQ level.” But now a study (full PDF here) from University College London finds that, in fact, “happiness is significantly associated with IQ,” meaning that more IQ = more happies.

Their study was based on the responses of almost 7000 subjects aged 16 and older. These subjects’ (verbal) IQs were estimated using the UK’s National Adult Reading Test. Subjects in the lowest IQ range (70-99) reported the lowest levels of happiness, and those in the highest group (IQ 120-129) reported being the happiest. These results were mediated by variables including income, health, and neuroticism.

The authors suggest that more education and more opportunities for employment, as well as better means of detecting (mental) health problems, might help enhance happiness levels in those with lower IQs.

It stands to reason that if you’re poor and/or unhealthy, you’ll also be less happy. But it also makes sense that a higher IQ could help mitigate these circumstances, as smarter people are more likely to be able to lift themselves out of poverty and to understand how to improve and maintain their own health.

At the same time, being smart might also lead to more existential anguish: what is the point of all this human suffering? Why do so many people believe so many foolish things? Why has this device been so poorly designed? Ad infinitum.


n-back-iqA popular form of working-memory training, known as the “dual n-back,” has gained much attention over the past year. But not all researchers are sold on the idea that the dual n-back is all the revolutionary, and many question whether the skills it enhances actually transfer to improving IQ more generally.

A new article in the journal Intelligence finds that although people got better at the training task itself, there were no significant gains in fluid intelligence or working memory capacity. “This does not support the notion that increasing one’s working memory capacity by training and practice could transfer to improvement on fluid intelligence.”

The n-back technique involves, for example, repeatedly watching letters appear on a screen, and then trying to remember which letter you saw “n” times earlier. Some say this exercise can enhance not only specific skills, but can also transfer to general intelligence on the whole, for example on tests like Raven’s Progressive Matrices. According to Susanne Jaeggi, the researcher most closely associated with promoting dual n-back’s wonders, it can and does transfer to fluid intelligence, and her 2008 paper “Improving fluid intelligence with training on working memory” is still enthusiastically cited.

“Although improvements were observed in every one of the cognitive tasks that were trained, no evidence was found for transfer effects to untrained tasks”

But a major 2010 review in Nature concluded otherwise, and the new Chooi and Thompson article in Intelligence also mentions other recent papers that question the ability of dual n-back training to boost IQ (in the sense of G, or general intelligence), one of which is a meta-analysis that found “memory training programs appear to produce short-term, specific training effects that do not generalize.”

Nonetheless, this “scientifically proven technique” continues to generate lots of good press, not to mention a nifty side business for its leading scientific proponents (replete with an affiliate program).


iq-hazardous-wasteA complement to enhancing cognitive abilities is finding ways of removing hazards that are known to decrease IQ, especially in children; a brief list would include exposure to air pollution, arsenic, and mercury. Now a study in Environmental Research has quantified the cognitive losses associated with one kind of toxic exposure, namely the lead that is released into the toxic brew found near hazardous waste sites.

This problem, they write, is “especially severe in lower income Asian countries where environmental regulations are non-existent, nonspecific or poorly enforced.” The authors found that in their study of about 190,00 children in seven Asian countries (Bangladesh, India, Indonesia, Kazakhstan, Pakistan, the Philippines, and Thailand), there is a substantial risk of “diminished intelligence as a consequence of exposure to elevated levels of lead in water and soil at hazardous waste sites,” and calculated this loss at between 5 and 15 IQ points, depending on which model was used. This kind of exposure, they conclude, is a “heretofore insufficiently examined contributor” to diminished cognitive abilities.


birth-controll-pill-iqA new study in the Journal of Women’s Health suggests that use of hormonal contraception (better known as the pill) can increase intelligence in women, especially in terms of visuo-spatial ability, speed, and flexibility, “even years after use is discontinued.” The pill also helps to prevent (or at least postpone) the natural decrease in intelligence that comes with old age. And the longer a woman takes the pill, the greater the cognitive benefits.

The realization that hormonal therapy increases IQ in women has been known for at least half a century; a seminal study (PDF) from 1952 showed that in 30 patients with a mean age of 75,

“after 12 months of treatment, verbal intelligence quotient (IQ) scores on the Wechsler Bellevue Intelligence Scale and scores on the Wechsler Memory Scale had increased significantly from pretreatment baseline in the estrogen-treated women, whereas verbal IQ scores decreased significantly in those given placebo during the same time span.”

But this new study is the first to show that these cognitive benefits also apply to pre-menopausal women, suggesting that it might be possible to increase intelligence in younger women with little more than a pill.


trust-and-iqIt’s long been known that trust correlates highly with education, as well as with cognitive ability. Is it the case that education “teaches” people how to be more trusting, or is it rather that people with a higher IQ are naturally more likely to be trusting? A new study in Intelligence suggests the latter, namely that most of this association can be explained by cognitive ability.

Why might brighter people also be more trusting? Perhaps because “rational actors are able to develop the insight that trusting relations are necessary if they want to achieve their goals.” Referencing Kierkegaard, the study’s authors suggest that “those with high levels of cognitive ability opt for the ‘leap into trust’: even if they know that occasionally they will be disappointed in the behavior of some of their fellow-citizens.”


nigeria-iq-innovationThe nation of Nigeria continues to be a surprising leader in the field of cognitive enhancement. After introducing a cognitive enhancer last year known as Cognitol (which is based on vinpocetine) and proudly promoting it as the country’s “first clinically proven IQ enhancer,” Nigeria has now launched Cogniskills, a new center devoted to learning enhancement.

At the Cogniskills facility, cognitive skills like attention, memory, and processing speed are trained using videogame-like exercises, either online, in groups, or in one-one-one sessions. Although similar cognitive-training programs already exist in the US and Europe, Cogniskills claims to be “a totally new concept and the first of its kind in Nigeria.”

And as the center’s founders write on their website, “Without accurately identifying weaknesses, students can give up and become plagued with life-long struggles.”


aspirin-women-iqA new study in the BMJ Open indicates that a daily dose of aspirin might delay cognitive decline in older women, at least those at an elevated risk of heart disease. As reported in ScienceDaily, the Swedish study involved 681 women aged 70-92 and at a high risk of heart disease and stroke. Their physical and mental skills were measured and then re-measured five years later.

Many of the women had already been taking daily aspirin to reduce the risk of heart attack or stroke. Although the average score across the whole group fell during this period, it fell substantially less in those women who kept taking daily aspirin during the 5-year study period. Compared with women who had not taken aspirin at all, those who had done so for all five years increased their score on the mini–mental state examination.