1. Study suggests blood vessels in eye linked with IQ, cognitive function

    June 9, 2013 by Ashley

    From the Association for Psychological Science press release:

    senior man visionThe width of blood vessels in the retina, located at the back of the eye, may indicate brain health years before the onset of dementia and other deficits, according to a new study published in Psychological Science, a journal of the Association for Psychological Science.

    Research shows that younger people who score low on intelligence tests, such as IQ, tend to be at higher risk for poorer health and shorter lifespan, but factors like socioeconomic status and health behaviors don’t fully account for the relationship. Psychological scientist Idan Shalev of Duke University and colleagues wondered whether intelligence might serve as a marker indicating the health of the brain, and specifically the health of the system of blood vessels that provides oxygen and nutrients to the brain.

    To investigate the potential link between intelligence and brain health, the researchers borrowed a technology from a somewhat unexpected domain: ophthalmology.

    Shalev and colleagues used digital retinal imaging, a relatively new and noninvasive method, to gain a window onto vascular conditions in the brain by looking at the small blood vessels of the retina, located at the back of the eye. Retinal blood vessels share similar size, structure, and function with blood vessels in the brain and can provide a way of examining brain health in living humans.

    The researchers examined data from participants taking part in the Dunedin Multidisciplinary Health and Development Study, a longitudinal investigation of health and behavior in over 1000 people born between April 1972 and March 1973 in Dunedin, New Zealand.

    The results were intriguing.

    Having wider retinal venules was linked with lower IQ scores at age 38, even after the researchers accounted for various health, lifestyle, and environmental risk factors that might have played a role.

    Individuals who had wider retinal venules showed evidence of general cognitive deficits, with lower scores on numerous measures of neurospsychological functioning, including verbal comprehension, perceptual reasoning, working memory, and executive function.

    Surprisingly, the data revealed that people who had wider venules at age 38 also had lower IQ in childhood, a full 25 years earlier.

    It’s “remarkable that venular caliber in the eye is related, however modestly, to mental test scores of individuals in their 30s, and even to IQ scores in childhood,” the researchers observe.

    The findings suggest that the processes linking vascular health and cognitive functioning begin much earlier than previously assumed, years before the onset of dementia and other age-related declines in brain functioning.

    “Digital retinal imaging is a tool that is being used today mainly by eye doctors to study diseases of the eye,” Shalev notes. “But our initial findings indicate that it may be a useful investigative tool for psychological scientists who want to study the link between intelligence and health across the lifespan.”

    The current study doesn’t address the specific mechanisms that drive the relationship between retinal vessels and cognitive functioning, but the researchers surmise that it may have to do with oxygen supply to the brain.

    Increasing knowledge about retinal vessels may enable scientists to develop better diagnosis and treatments to increase the levels of oxygen into the brain and by that, to prevent age-related worsening of cognitive abilities,” they conclude.

     

     


  2. Study suggests IQ predicted by ability to filter motion

    May 27, 2013 by Ashley

    From the University of Rochester press release via EurekAlert!:

    mind mazeA brief visual task can predict IQ, according to a new study.

    This surprisingly simple exercise measures the brain’s unconscious ability to filter out visual movement. The study shows that individuals whose brains are better at automatically suppressing background motion perform better on standard measures of intelligence.

    The test is the first purely sensory assessment to be strongly correlated with IQ and may provide a non-verbal and culturally unbiased tool for scientists seeking to understand neural processes associated with general intelligence.

    “Because intelligence is such a broad construct, you can’t really track it back to one part of the brain,” says Duje Tadin, a senior author on the study and an assistant professor of brain and cognitive sciences at the University of Rochester. “But since this task is so simple and so closely linked to IQ, it may give us clues about what makes a brain more efficient, and, consequently, more intelligent.”

    The unexpected link between IQ and motion filtering was reported online in the Cell Press journal Current Biology on May 23 by a research team lead by Tadin and Michael Melnick, a doctoral candidate in brain and cognitive sciences at the University of Rochester.

    In the study, individuals watched brief video clips of black and white bars moving across a computer screen. Their sole task was to identify which direction the bars drifted: to the right or to the left. The bars were presented in three sizes, with the smallest version restricted to the central circle where human motion perception is known to be optimal, an area roughly the width of the thumb when the hand is extended. Participants also took a standardized intelligence test.

    As expected, people with higher IQ scores were faster at catching the movement of the bars when observing the smallest image. The results support prior research showing that individuals with higher IQs make simple perceptual judgments swifter and have faster reflexes. “Being ‘quick witted’ and ‘quick on the draw’ generally go hand in hand,” says Melnick.

    But the tables turned when presented with the larger images. The higher a person’s IQ, the slower they were at detecting movement. “From previous research, we expected that all participants would be worse at detecting the movement of large images, but high IQ individuals were much, much worse,” says Melnick. That counter-intuitive inability to perceive large moving images is a perceptual marker for the brain’s ability to suppress background motion, the authors explain. In most scenarios, background movement is less important than small moving objects in the foreground. Think about driving in a car, walking down a hall, or even just moving your eyes across the room. The background is constantly in motion.

    The key discovery in this study is how closely this natural filtering ability is linked to IQ. The first experiment found a 64 percent correlation between motion suppression and IQ scores, a much stronger relationship than other sensory measures to date. For example, research on the relationship between intelligence and color discrimination, sensitivity to pitch, and reaction times have found only a 20 to 40 percent correlation. “In our first experiment, the effect for motion was so strong,” recalls Tadin, “that I really thought this was a fluke.”

    So the group tried to disprove the findings from the initial 12-participant study conducted while Tadin was at Vanderbilt University working with co-author Sohee Park, a professor of psychology. They reran the experiment at the University of Rochester on a new cohort of 53 subjects, administering the full IQ test instead of an abbreviated version and the results were even stronger; correlation rose to 71 percent. The authors also tested for other possible explanations for their findings.

    For example, did the surprising link to IQ simply reflect a person’s willful decision to focus on small moving images? To rule out the effect of attention, the second round of experiments randomly ordered the different image sizes and tested other types of large images that have been shown not to elicit suppression. High IQ individuals continued to be quicker on all tasks, except the ones that isolated motion suppression. The authors concluded that high IQ is associated with automatic filtering of background motion.

    “We know from prior research which parts of the brain are involved in visual suppression of background motion. This new link to intelligence provides a good target for looking at what is different about the neural processing, what’s different about the neurochemistry, what’s different about the neurotransmitters of people with different IQs,” says Tadin.

    The relationship between IQ and motion suppression points to the fundamental cognitive processes that underlie intelligence, the authors write. The brain is bombarded by an overwhelming amount of sensory information, and its efficiency is built not only on how quickly our neural networks process these signals, but also on how good they are at suppressing less meaningful information. “Rapid processing is of little utility unless it is restricted to the most relevant information,” the authors conclude.

    The researchers point out that this vision test could remove some of the limitations associated with standard IQ tests, which have been criticized for cultural bias. “Because the test is simple and non-verbal, it will also help researchers better understand neural processing in individuals with intellectual and developmental disabilities,” says co-author Loisa Bennetto, an associate professor of psychology at the University of Rochester.


  3. Study links flame retardants to hyperactivity, lower intelligence

    May 6, 2013 by Ashley

    From the University of Cincinnati press release via HealthCanal:

    lab_researchA new study led by researchers at the University of Cincinnati (UC) College of Medicine shows that prenatal exposure to chemical flame retardants used in everyday products such as baby strollers, carpeting and electronics is associated with hyperactivity and lower intelligence in early childhood.

    The research on the chemicals, known as polybrominated diphenyl ethers (PBDEs), is being presented Monday, May 6, at the Pediatric Academic Societies (PAS) annual meeting in Washington, D.C. The study’s lead author is Aimin Chen, MD, PhD, an assistant professor of environmental health at UC.

    “In animal studies, PBDEs can disrupt thyroid hormone and cause hyperactivity and learning problems,” says Chen. “Our study adds to several other human studies to highlight the need to reduce exposure to PBDEs in pregnant women.”

    Chen and his colleagues at UC collected blood samples from 309 pregnant women enrolled in a study at Cincinnati Children’s Hospital Medical Center to measure PBDE levels. They also performed intelligence and behavior tests on the women’s children annually until they were 5 years old.

    We found that maternal exposure to PBDEs, a group of brominated flame retardants mostly withdrawn from the U.S. market in 2004, was associated with deficits in child cognition at age 5 years and hyperactivity at ages 2 to 5 years,” Chen says. A 10-fold increase in maternal PBDEs was associated with about a four-point IQ deficit in 5-year-old children.

    Even though PBDEs, except Deca-BDEs, are not used as a flame retardant in the United States anymore, they are found on many consumer products bought several years ago. In addition, the chemicals are not easily biodegradable, so they remain in human tissues and are transferred to the developing fetus.

    Because PBDEs exist in the home and office environment as they are contained in old furniture, carpet pads, foams and electronics, the study raises further concern about their toxicity in developing children,” Chen says.

     


  4. Study suggests emotional intelligence trumps IQ in dentist-patient relationships

    April 29, 2013 by Ashley

    From the Case Western Reserve University press release via ScienceDaily:

    TeethIQ directly relates to how students perform on tests in the first two years of dental school. But emotional intelligence (EI) trumps IQ in how well dental students work with patients, report researchers from Case Western Reserve University’s School of Dental Medicine and Weatherhead School of Management.

    EI influences how well dental students recognize and manage their emotions and professional relationships, explain Kristin Victoroff, DDS, PhD, and Richard Boyatzis, PhD, in the current issue of the Journal of Dental Education article, “What is the Relationship Between Emotional Intelligence and Dental School Clinical Performance?”

    EI differs from IQ, which measures the ability to think and perform on tests. EI, also a form of intelligence, is the ability to read one’s own moods and those of others, remain calm under pressure and be optimistic and adaptable to change.

    “Emotional intelligence is distinct from traditional intelligence or IQ,” said Boyatzis, a Distinguished University Professor and professor of organizational behavior, psychology and cognitive science. He developed the EI management model and coauthored a book series on how to use it in business. He added that people need both to be successful.

    The study evolved from discussions by heath-care educators about whether EI should be used in the admissions process or as a measure in clinical practice.

    Boyatzis explained that other standardized admissions tests are equally incapable of predicting success in other fields, like medicine and management. “Such tests predict grades in courses but not effectiveness in professions. This is the first test of this relationship in dentistry, and one of the clearest studies of the dynamics,” he said.

    Until now, no evidence was available to determine if EI had a connection to clinical education, said Victoroff, the associate dean for education and associate professor of community dentistry.

    The highly competitive admission process to dental school involves high scores on academic and perceptual ability tests. But that could change as educators understand the important role of EI in patient care.

    Educators questioned why some high-performing students in the classroom didn’t fare as well in the clinic. Researchers wondered if EI was a factor.

    Students at Case Western Reserve dental school were among the first in dentistry to see if EI impacted clinical successes, as it does in corporate management.

    The researchers recruited third- and fourth-year students, who receive clinical training under the guidance of two preceptors (part-time faculty who are practicing community dentists) that assess clinical performance.

    One hundred of the 136 students from the two classes participated. Students themselves plus other individuals they work with were asked to complete a 72-item questionnaire from the Emotional Competence Inventory-University. EI competencies are grouped in four areas: self-awareness, self-management, social-awareness and relationship management.

    Overall clinical performance was determined by averaging the preceptors’ assessments of a student’s overall clinical performance over several rating periods.

    In determining a student’s overall clinical performance, preceptors consider such factors as diagnosis and treatment planning skills, work ethic and time utilization, preparation and organization, professionalism, patient management, knowledge and technical skills and ability to self-assess one’s work.

    The analysis looked at the clinical grade and the EI assessment to see if there was a correlation between high EI scores and high clinical performance. The researchers ruled out the student’s year in school and gender in the analysis after finding those factors made no significant differences.

    Their findings showed that a high EI related to excellent clinical performance. The researchers found EI skills in self-management were significant predictors of clinical grades. Self-management skills involve self-control, achievement orientation, initiative, trustworthiness, conscientiousness, adaptability and optimism.

    They did not find a strong EI-clinical association to self- and social-awareness.

    EI scores for relationship management, which relates to the ability to influence others, were harder to determine due to the transient nature between the student dentist and patient during the two-year clinical training.

    The researchers concluded that teaching EI competencies could better serve patients and help students succeed. They recommended future studies extend EI assessments to practicing dentists to determine EI’s impact in the professional setting.


  5. Study suggests measuring IQ by singular standardized test may be misleading

    December 30, 2012 by Sue

    From the University of Western Ontario press release via EurekAlert!:

    studying_hardAfter conducting the largest online intelligence study on record, a Western University-led research team has concluded that the notion of measuring one’s intelligence quotient or IQ by a singular, standardized test is highly misleading.

    The findings from the landmark study, which included more than 100,000 participants, were published today in the journal Neuron. The article, “Fractionating human intelligence,” was written by Adrian M. Owen and Adam Hampshire from Western’s Brain and Mind Institute (London, Canada) and Roger Highfield, Director of External Affairs, Science Museum Group (London, U.K).

    Utilizing an online study open to anyone, anywhere in the world, the researchers asked respondents to complete 12 cognitive tests tapping memory, reasoning, attention and planning abilities, as well as a survey about their background and lifestyle habits.

    “The uptake was astonishing,” says Owen, the Canada Excellence Research Chair in Cognitive Neuroscience and Imaging and senior investigator on the project. “We expected a few hundred responses, but thousands and thousands of people took part, including people of all ages, cultures and creeds from every corner of the world.”

    The results showed that when a wide range of cognitive abilities are explored, the observed variations in performance can only be explained with at least three distinct components: short-term memory, reasoning and a verbal component.

    No one component, or IQ, explained everything. Furthermore, the scientists used a brain scanning technique known as functional magnetic resonance imaging (fMRI), to show that these differences in cognitive ability map onto distinct circuits in the brain.

    With so many respondents, the results also provided a wealth of new information about how factors such as age, gender and the tendency to play computer games influence our brain function.

    “Regular brain training didn’t help people’s cognitive performance at all yet aging had a profound negative effect on both memory and reasoning abilities,” says Owen.

    Hampshire adds, “Intriguingly, people who regularly played computer games did perform significantly better in terms of both reasoning and short-term memory. And smokers performed poorly on the short-term memory and the verbal factors, while people who frequently suffer from anxiety performed badly on the short-term memory factor in particular”.

    To continue the groundbreaking research, the team has launched a new version of the tests at http://www.cambridgebrainsciences.com/theIQchallenge

    “To ensure the results aren’t biased, we can’t say much about the agenda other than that there are many more fascinating questions about variations in cognitive ability that we want to answer,” explains Hampshire.


  6. Study links healthy diets to higher IQ in children

    August 8, 2012 by Sue

    From the University of Adelaide press release via ScienceDaily:

    Children fed healthy diets in early age may have a slightly higher IQ, while those on heavier junk food diets may have a slightly reduced IQ, according to new research from the University of Adelaide.

    The study – led by University of Adelaide Public Health researcher Dr Lisa Smithers – looked at the link between the eating habits of children at six months, 15 months and two years, and their IQ at eight years of age.

    The study of more than 7000 children compared a range of dietary patterns, including traditional and contemporary home-prepared food, ready-prepared baby foods, breastfeeding, and ‘discretionary’ or junk foods.

    “Diet supplies the nutrients needed for the development of brain tissues in the first two years of life, and the aim of this study was to look at what impact diet would have on children’s IQs,” Dr Smithers says.

    “We found that children who were breastfed at six months and had a healthy diet regularly including foods such as legumes, cheese, fruit and vegetables at 15 and 24 months, had an IQ up to two points higher by age eight.

    “Those children who had a diet regularly involving biscuits, chocolate, lollies, soft drinks and chips in the first two years of life had IQs up to two points lower by age eight.

    “We also found some negative impact on IQ from ready-prepared baby foods given at six months, but some positive associations when given at 24 months,” Dr Smithers says.

    Dr Smithers says this study reinforces the need to provide children with healthy foods at a crucial, formative time in their lives.

    While the differences in IQ are not huge, this study provides some of the strongest evidence to date that dietary patterns from six to 24 months have a small but significant effect on IQ at eight years of age,” Dr Smithers says.

    “It is important that we consider the longer-term impact of the foods we feed our children,” she says.

    The results of this study have been published online in the European Journal of Epidemiology.


  7. Study suggests 10 percent of variance in intelligence is linked to “global brain connectivity”

    August 3, 2012 by Sue

    From the Washington University in St. Louis press release:

    When it comes to intelligence, what factors distinguish the brains of exceptionally smart humans from those of average humans?

    As science has long suspected, overall brain size matters somewhat, accounting for about 6.7 percent of individual variation in intelligence. More recent research has pinpointed the brain’s lateral prefrontal cortex, a region just behind the temple, as a critical hub for high-level mental processing, with activity levels there predicting another 5 percent of variation in individual intelligence.

    Now, new research from Washington University in St. Louis suggests that another 10 percent of individual differences in intelligence can be explained by the strength of neural pathways connecting the left lateral prefrontal cortex to the rest of the brain.

    Published in the Journal of Neuroscience, the findings establish “global brain connectivity” as a new approach for understanding human intelligence.

    “Our research shows that connectivity with a particular part of the prefrontal cortex can predict how intelligent someone is,” suggests lead author Michael W. Cole, PhD, a postdoctoral research fellow in cognitive neuroscience at Washington University.

    The study is the first to provide compelling evidence that neural connections between the lateral prefrontal cortex and the rest of the brain make a unique and powerful contribution to the cognitive processing underlying human intelligence, says Cole, whose research focuses on discovering the cognitive and neural mechanisms that make human behavior uniquely flexible and intelligent.

    “This study suggests that part of what it means to be intelligent is having a lateral prefrontal cortex that does its job well; and part of what that means is that it can effectively communicate with the rest of the brain,” says study co-author Todd Braver, PhD, professor of psychology in Arts & Sciences and of neuroscience and radiology in the School of Medicine. Braver is a co-director of the Cognitive Control and Psychopathology Lab at Washington University, in which the research was conducted.

    One possible explanation of the findings, the research team suggests, is that the lateral prefrontal region is a “flexible hub” that uses its extensive brain-wide connectivity to monitor and influence other brain regions in a goal-directed manner.

    “There is evidence that the lateral prefrontal cortex is the brain region that ‘remembers’ (maintains) the goals and instructions that help you keep doing what is needed when you’re working on a task,” Cole says. “So it makes sense that having this region communicating effectively with other regions (the ‘perceivers’ and ‘doers’ of the brain) would help you to accomplish tasks intelligently.”

    While other regions of the brain make their own special contribution to cognitive processing, it is the lateral prefrontal cortex that helps coordinate these processes and maintain focus on the task at hand, in much the same way that the conductor of a symphony monitors and tweaks the real-time performance of an orchestra.

    “We’re suggesting that the lateral prefrontal cortex functions like a feedback control system that is used often in engineering, that it helps implement cognitive control (which supports fluid intelligence), and that it doesn’t do this alone,” Cole says.

    The findings are based on an analysis of functional magnetic resonance brain images captured as study participants rested passively and also when they were engaged in a series of mentally challenging tasks associated with fluid intelligence, such as indicating whether a currently displayed image was the same as one displayed three images ago.

    Previous findings relating lateral prefrontal cortex activity to challenging task performance were supported. Connectivity was then assessed while participants rested, and their performance on additional tests of fluid intelligence and cognitive control collected outside the brain scanner was associated with the estimated connectivity.

    Results indicate that levels of global brain connectivity with a part of the left lateral prefrontal cortex serve as a strong predictor of both fluid intelligence and cognitive control abilities.

    Although much remains to be learned about how these neural connections contribute to fluid intelligence, new models of brain function suggested by this research could have important implications for the future understanding — and perhaps augmentation — of human intelligence.

    The findings also may offer new avenues for understanding how breakdowns in global brain connectivity contribute to the profound cognitive control deficits seen in schizophrenia and other mental illnesses, Cole suggests.

    Other co-authors include Tal Yarkoni, PhD, a postdoctoral fellow in the Department of Psychology and Neuroscience at the University of Colorado at Boulder; Grega Repovs, PhD, professor of psychology at the University of Ljubljana, Slovenia; and Alan Anticevic, an associate research scientist in psychiatry at Yale University School of Medicine.

    Funding from the National Institute of Mental Health supported the study (National Institutes of Health grants MH66088, NR012081, MH66078, MH66078-06A1W1, and 1K99MH096801).


  8. Study suggests IQ may be predictor of propensity toward violence in incarceration

    May 1, 2012 by Sue

    From the UT Dallas press release:

    A prison inmate’s IQ, as well as the average IQ of a prison unit, can play a role in predicting violent prison misconduct, according to a recently published UT Dallas study.

    The study, featured in the latest issue of the academic journal Intelligence, is a rare examinination of the relationship between intelligence and violent misconduct in prison. Previous research has shown the link between IQ and crime in society. UT Dallas doctoral student, Brie Diamond, led the study, which is co-authored by UT Dallas criminologists Dr. Robert Morris and Dr. J.C. Barnes, who teach in the School of Economic, Political and Policy Sciences.

    Using a multi-level modeling approach, the researchers analyzed three years of incarceration from a random sample of 2,500 male inmates across 30 prison units who entered prison between August 2004 and June 2006. The researchers looked at whether an inmate was reported for violent behavior against another inmate or against a prison staff member, resulting in at least a minor injury.

    The findings show that inmates with above average IQs were at a reduced risk of being involved in a violent incident and individuals assigned to units with a higher average IQ score were significantly less likely to commit violent behavior.

    Diamond, who is earning a Ph.D. in criminology, said an individual’s IQ captures the ability to navigate a social environment in addition to assessing academic capabilities.

    “It’s not too surprising then that people who are deficient in these regards would be more prone to respond physically and lack an advanced repertoire for handling situations,” she said.

    Diamond said the findings could help prison officials better understand how the average IQ of a prison unit has an effect on prison violence. It is a factor that officials could take into account when classifying inmates.

    “What’s important about these findings from a research perspective is that we’ve isolated yet another piece of the puzzle as far as what leads to misconduct. So in the future, researchers looking into violence should control for cognitive ability,” she said.

    Morris said the findings regarding the collective IQ of a prison unit was perhaps the most interesting part of the study.

    “We definitely don’t understand the entire package as far as how IQ explains the process leading to an inmate engaging in misbehavior,” Morris said. “It’s more about IQ playing a role, and that it’s not only about a particular person’s IQ, but it’s about collective IQ in an environment of confinement.”

    Morris said it’s a tremendous accomplishment for a graduate student such as Diamond to get her work published in a prestigious journal.

    “It is rare,” he said. “It’s pretty exciting for a criminologist to get a publication in Intelligence. It’s a big deal.”

    Diamond said she was shocked and excited when she learned that Intelligence had accepted the paper.

    “I honestly danced around my kitchen,” she said. “The impact factor for the journal is high compared to similar journals.”

    Diamond earned her bachelor’s degree in psychology with a minor in criminal justice from UT Dallas, as well her master’s degree in criminology. She plans to work as a professor following the completion of her doctoral degree in May 2013.

     


  9. Study suggests evolution of intelligence and larger brain sizes can be driven by cooperation

    April 19, 2012 by Sue

    From the Trinity College Dublin press release via EurekAlert!:

    Scientists have discovered proof that the evolution of intelligence and larger brain sizes can be driven by cooperation and teamwork, shedding new light on the origins of what it means to be human. The study appears online in the journal Proceedings of the Royal Society B and was led by scientists at Trinity College Dublin: PhD student, Luke McNally and Assistant Professor Dr Andrew Jackson at the School of Natural Sciences in collaboration with Dr Sam Brown of the University of Edinburgh.

    The researchers constructed computer models of artificial organisms, endowed with artificial brains, which played each other in classic games, such as the ‘Prisoner’s Dilemma’, that encapsulate human social interaction. They used 50 simple brains, each with up to 10 internal processing and 10 associated memory nodes.

    The brains were pitted against each other in these classic games. The game was treated as a competition, and just as real life favours successful individuals, so the best of these digital organisms which was defined as how high they scored in the games, less a penalty for the size of their brains were allowed to reproduce and populate the next generation of organisms.

    By allowing the brains of these digital organisms to evolve freely in their model the researchers were able to show that the transition to cooperative society leads to the strongest selection for bigger brains. Bigger brains essentially did better as cooperation increased.

    The social strategies that emerge spontaneously in these bigger, more intelligent brains show complex memory and decision making. Behaviours like forgiveness, patience, deceit and Machiavellian trickery all evolve within the game as individuals try to adapt to their social environment.

    “The strongest selection for larger, more intelligent brains, occurred when the social groups were first beginning to start cooperating, which then kicked off an evolutionary Machiavellian arms race of one individual trying to outsmart the other by investing in a larger brain. Our digital organisms typically start to evolve more complex ‘brains’ when their societies first begin to develop cooperation.” explained Dr Andrew Jackson.

    The idea that social interactions underlie the evolution of intelligence has been around since the mid-70s, but support for this hypothesis has come largely from correlative studies where large brains were observed in more social animals. The authors of the current research provide the first evidence that mechanistically links decision making in social interactions with the evolution of intelligence.

    This study highlights the utility of evolutionary models of artificial intelligence in answering fundamental biological questions about our own origins.

    “Our model differs in that we exploit the use of theoretical experimental evolution combined with artificial neural networks to actually prove that yes, there is an actual cause-and-effect link between needing a large brain to compete against and cooperate with your social group mates.”

    “Our extraordinary level of intelligence defines mankind and sets us apart from the rest of the animal kingdom. It has given us the arts, science and language, and above all else the ability to question our very existence and ponder the origins of what makes us unique both as individuals and as a species,” concluded PhD student and lead author Luke McNally.


  10. Study suggests excessive worrying may have co-evolved with intelligence

    April 12, 2012 by Sue

    From the SUNY Downstate Medical Center via EurekAlert!:

    Worrying may have evolved along with intelligence as a beneficial trait, according to a recent study by scientists at SUNY Downstate Medical Center and other institutions. Jeremy Coplan, MD, professor of psychiatry at SUNY Downstate, and colleagues found that high intelligence and worry both correlate with brain activity measured by the depletion of the nutrient choline in the subcortical white matter of the brain. According to the researchers, this suggests that intelligence may have co-evolved with worry in humans.

    “While excessive worry is generally seen as a negative trait and high intelligence as a positive one, worry may cause our species to avoid dangerous situations, regardless of how remote a possibility they may be,” said Dr. Coplan. “In essence, worry may make people ‘take no chances,’ and such people may have higher survival rates. Thus, like intelligence, worry may confer a benefit upon the species.”

    In this study of anxiety and intelligence, patients with generalized anxiety disorder (GAD) were compared with healthy volunteers to assess the relationship among intelligence quotient (IQ), worry, and subcortical white matter metabolism of choline. In a control group of normal volunteers, high IQ was associated with a lower degree of worry, but in those diagnosed with GAD, high IQ was associated with a greater degree of worry. The correlation between IQ and worry was significant in both the GAD group and the healthy control group. However, in the former, the correlation was positive and in the latter, the correlation was negative. Eighteen healthy volunteers (eight males and 10 females) and 26 patients with GAD (12 males and 14 females) served as subjects.

    Previous studies have indicated that excessive worry tends to exist both in people with higher intelligence and lower intelligence, and less so in people of moderate intelligence. It has been hypothesized that people with lower intelligence suffer more anxiety because they achieve less success in life.

    The results of their study, “The Relationship between Intelligence and Anxiety: An Association with Subcortical White Matter Metabolism,” was published in a recent edition of Frontiers in Evolutionary Neuroscience, and can be read at http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3269637/pdf/fnevo-03-00008.pdf .

    The study was selected and evaluated by a member of the Faculty of 1000 (F1000), placing it in their library of the top 2% of published articles in biology and medicine.