Chapter 1. Biological Psychology: Scope and Outlook

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Alison Abbott Activists occupied an animal facility at the University of Milan, Italy, at the weekend, releasing mice and rabbits and mixing up cage labels to confuse experimental protocols. Researchers at the university say that it will take years to recover their work. Many of the animals at the facility are genetic models for psychiatric disorders such as autism and schizophrenia. No arrests have been made following the 12-hour drama, which took place on Saturday, although the university says that it will press charges against the protesters. The activists took some of the animals and were told during negotiations that they would be permitted to come back later and take more. The attack was staged by the animal-rights group that calls itself Fermare Green Hill (or Stop Green Hill), in reference to the Green Hill dog-breeding facility near Brescia, Italy, which it targets for closure. Five activists entered laboratories in the university’s pharmacology department on Saturday morning. The lack of signs of a break-in suggests that the activists may have used an illegally acquired electronic card, says pharmacologist Francesca Guidobono-Cavalchini, who works there. They prised open the reinforced doors of the facility on the fourth floor, and two of them chained themselves by the neck to the main double doors such that any attempt to open the doors could have endangered their lives. © 2013 Nature Publishing Group

Keyword: Animal Rights
Link ID: 18059 - Posted: 04.23.2013

By Suzy Gage When I started my PhD a few years ago, I thought that certain psychological findings were established fact. The next four years were an exercise in disillusionment. If the effects I was seeking to explore were so reliable, so established, why could I not detect them? There is growing interest in the need to improve reliability in science. Many drugs show promise at the design and pre-clinical phases, only to fail (at great expense) in clinical trials. Many of the most hyped scientific discoveries eventually cannot be replicated. Worryingly for science (but somewhat comforting for my self-esteem as a researcher) this may be because many of the conclusions drawn from published research findings are false. A major factor that influences the reliability of science is statistical power. We cannot measure everyone or everything, so we take samples and use statistical inference to determine the probability that the results we observe in our sample reflect some underlying scientific truth. Statistical power determines whether we accurately conclude if there is an effect or not. Statistical power is the ability of a study to detect an effect (eg higher rates of cancer in smokers) given that an effect actually exists (smoking actually is associated with increased risk of cancer). Power is related to the size of the study sample (the number of smokers and non-smokers we test) and the size of the real effect (the magnitude of the increased risk associated with smoking). Larger studies have more power and can detect smaller, more subtle effects. Small studies have lower power and can only detect larger effects reliably. © 2013 Guardian News and Media Limited

Keyword: Miscellaneous
Link ID: 18019 - Posted: 04.11.2013

By Tina Hesman Saey Mice are poor stand-ins for people in experiments on some types of inflammation, a new study concludes. But some scientists say that critique discounts the value of mouse studies, many of which simply couldn’t be done without the animals. More attention — and money — should go toward studying disease in people than on mouse research, a consortium of scientists contends online February 11 in the Proceedings of the National Academy of Sciences. Too often, researchers make a discovery in mice and assume that humans will react in the same way, says study coauthor Ronald Tompkins, chief of the Massachusetts General Hospital burn service. “The presumption is not justifiable,” he says. As a result, drug trials — often based heavily on data gleaned from studies with mice — can fail. But other scientists say that critique isn’t new and is overstated. Clinical trials are unsuccessful for many reasons, says Derry Roopenian, an immunologist and mouse geneticist at the Jackson Laboratory in Bar Harbor, Maine. “There’s frailty all along the process. That’s not a failure of the mouse.” He and other critics worry that the study, conducted with a generic strain of laboratory mouse called Black6, unfairly tarnishes the reputation of all mice, even ones engineered to be as much like humans as possible. The group’s conclusions, were they accepted by policy makers, could set back biomedical research by jeopardizing funding for mouse studies, critics warn. “Without the mouse, progress is going to be slowed to a standstill,” Roopenian says. © Society for Science & the Public 2000 - 2013

Keyword: Animal Rights
Link ID: 17785 - Posted: 02.12.2013

by Michael Marshall Humans aren't built for giving birth. Babies' heads are big to accommodate their big brains, but the mother's hips are small because they walk upright. As a result, birth takes hours and is extremely painful – and midwives almost always help out. Other animals may find birth difficult, particularly if the babies have been gestating for a long time and have grown large. Nevertheless, most mammals have it easier than humans. Monkeys give birth in less than ten minutes. So it is a surprise that female black snub-nosed monkeys may be assisted by "midwives" when they give birth. This behaviour has only been seen once in this species, but it suggests that it's not just human mothers that need help giving birth. Black snub-nosed monkeys live in societies called bands, which can be over 400 strong. Each is divided into smaller groups of around 10 monkeys. Most groups contain one male and several females plus offspring, but there are also all-male groups. Wen Xiao of Dali University in Yunnan, China, and colleagues have been observing black snub-nosed monkeys in the province for years, but had never seen one give birth: the monkeys normally deliver at night. Then on 18 March last year, they got lucky. © Copyright Reed Business Information Ltd.

Keyword: Evolution
Link ID: 17781 - Posted: 02.11.2013

By Samuel McNerney How much does environment influence intelligence? Several years ago University of Virginia Professor Eric Turkheimer demonstrated that growing up in an impoverished and chaotic household suppresses I.Q. – without nurture, innate advantages vanish. What about genes? They matter too. After decades of research most psychologists agree that somewhere between 50% and 80% of intelligence is genetic. After all, numerous studies demonstrate that identical twins raised apart have remarkably similar I.Q.’s. A 2008 paper out of the University of Michigan turned all of this on its head. The researchers led by Susanne M. Jaeggi and Martin Buschkuehl, now at the University of Maryland, found that participants who engaged in short sessions of “cognitive training” that targeted working memory with a simple but difficult game known as the n-back task boosted a core feature of general intelligence called fluid intelligence. Crystalized intelligence improves with age and experience. Fluid intelligence, in contrast, is the capacity to make insights, solve new problems and perceive new patterns to new situations independent of previous knowledge. For decades researchers believed that fluid intelligence was immutable during adulthood because it was largely determined by genetics. The implication of the 2008 study suggested otherwise: with some cognitive training people could improve fluid intelligence and, therefore, become smarter. This brings me to a brand new paper recently published in the journal Neuroscience by DRDC Toronto researcher and Adjunct Assistant Professor of Psychology at the University of Toronto-Scarborough, Oshin Vartanian. In the study, Vartanian and his team asked if working memory training improved performance on a test of divergent thinking known as the Alternate Uses Task. Psychological research demonstrates that divergent thinking “loads” on working memory, meaning that when people engage a divergent thinking task their working memory capacity is accessed accordingly. © 2013 Scientific American,

Keyword: Intelligence; Learning & Memory
Link ID: 17771 - Posted: 02.06.2013

By Gareth Cook Just about every dog owner is convinced their dog is a genius. For a long time, scientists did not take their pronouncements particularly seriously, but new research suggests that canines are indeed quite bright, and in some ways unique. Brian Hare, an associate professor in the Department of Evolutionary Anthropology and the Center for Cognitive Neuroscience at Duke University, is one of the leading figures in the quest to understand what dogs know. The founder of the Duke Canine Cognition Center, Hare has now written a book, “The Genius of Dogs,” with his wife, the journalist Vanessa Woods. Hare answered questions from Mind Matters editor Gareth Cook. Cook: What is the biggest misconception people have about the dog mind? Hare: That there are “smart” dogs and “dumb” dogs. There’s still this throwback to a uni-dimensional version of intelligence, as though there is only one type of intelligence that you either have more or less of. In reality there are different types of intelligence. Different dogs are good at different things. Unfortunately, the very clever strategies some dogs are using are not apparent without playing a cognitive game. This means people can often underestimate the intelligence of their best friend. The pug drooling on your shoe may not look like the brightest bulb in the box, but she comes from a long line of successful dogs and is a member of the most successful mammal species on the planet besides us. Rest assured – she is a genius. © 2013 Scientific American

Keyword: Intelligence; Evolution
Link ID: 17770 - Posted: 02.06.2013

by Virginia Morell The male Eurasian jay is an accommodating fellow. When his mate has been feasting steadily on mealworm larvae, he realizes that she'd now prefer to dine on wax moth larvae, which he feeds her himself. The finding adds to a small but growing number of studies that show that some animals have something like the human ability to understand what others are thinking. "It's great for a first test of this ability in birds," says Thomas Bugnyar, a cognitive biologist at the University of Vienna in Austria who was not involved in the work. Scientists still debate about whether even our closest ape relatives can attribute an unseen, mental desire to another; some continue to argue that this is a peculiarly human talent. "But some of us think that some aspects of this ability should be found here and there in different species," Bugnyar says, "and so it is good to have this jay study to compare" with the other studies on primates, humans, and human children. Male Eurasian jays feed their mates during courtship displays, says Ljerka Ostojić, a comparative psychologist and postdoc at the University of Cambridge in the United Kingdom who led the study. Because of that behavior, Ostojić and her colleagues thought that the jays might be good subjects for testing whether these birds understand their mates' desires. The group's previous research had shown that Eurasian jays and scrub jays can plan for the future. "It is commonly thought that any action animals take is determined solely by whatever they want at that moment," Ostojić says, "but the jays also plan for needs in the future." © 2010 American Association for the Advancement of Science

Keyword: Intelligence; Evolution
Link ID: 17766 - Posted: 02.05.2013

Jordan Heller The note, which threatened to kidnap O'Leary and went on to reference myriad tortures including dismemberment, disembowelment, Drano and napalm, was published on Negotiation Is Over (NIO), a website that acts as a one-stop shop for animal rights extremists looking to gather intelligence on potential targets. In addition to labeling O'Leary—a professor at Detroit's Wayne State University whose studies on congestive heart failure involve experiments on rodents and occasionally dogs—a sadistic animal torturer, it published his photo and home address. In an email to O'Leary alerting him of the post, Camille Marino, who until last month ran NIO out of her home in Wildwood, Fla., told the professor that some of her "associates" would be paying him a visit to take pictures of his home. "Then you can join ‘NIO's most wanted,'" she wrote. "I hope you die a slow and painful death." Arson, Cracked Testicles, and Internet Death Threats: How Animal Rights Extremists Are Learning From the People Who Murdered George TillerAnimal right activist Camille Marino, who has done stints as an investment banker and law student, was convicted last year of repeatedly threatening a medical researcher. In December, a Michigan judge sentenced Marino, 48, to six months in prison and three years probation for charges related to her off- and online stalking of O'Leary, who at trial called Marino a "clearly disturbed individual, who was threatening me personally, threatening my children, threatening my home."

Keyword: Animal Rights
Link ID: 17694 - Posted: 01.19.2013

By Ashutosh Jogalekar As marijuana is being legalized in Washington and Colorado states, its proliferation and use raise legitimate issues regarding its dose-dependent and long-term effects. One key question is whether pot leads to cognitive decline and a lowering of IQ, especially if its consumption is started at an early age. Answering this question is important for users, families and policy makers to have a realistic idea of personal and legal policies regarding widespread cannabis use. Last year, Madeline Meier and her group from Duke University reported results from the so-called Dunedin study which tracked a group of 1037 people from their birth to age 38. These volunteers’ pot smoking histories were monitored at periodic intervals from age 18 onwards. The study found a troubling decline of IQ and cognitive abilities among regular pot smokers, especially those whose habit kicked in during their teens. No explicit causal relationship was assigned between the two facts, but the correlation was positive and significant. The study naturally raised a lot of questions regarding the wisdom of early pot use, especially in light of its current legalization in two states. Now a study by Ole Rogeberg from the Ragnar Frisch Center for Research in Norway has called this study into question, both for its methodology and its conclusions. The first thing to realize about any such study, even if you don’t know the details, is that there are going to be several confounding socioeconomic factors in assessing any relationship between cannabis use and IQ. Medicine and psychology are not exact sciences, and following a large sample of people for 38 years and assessing correlation – let alone causation – between any two factors is going to be confounded by a large number of other correlated and uncorrelated variables in an inherently uncontrolled experiment. © 2013 Scientific American,

Keyword: Drug Abuse; Intelligence
Link ID: 17690 - Posted: 01.17.2013

By CLAUDIA DREIFUS In a world of proliferating professions, S. Matthew Liao has a singular title: neuroethicist. Dr. Liao, 40, the director of the bioethics program at New York University, deploys the tools of philosophy, history, psychology, religion and ethics to understand the impact of neuroscientific breakthroughs. You’re a philosopher by training. How did philosophy lead to neuroethics? Mine’s the typical immigrant’s story. My family moved to Cincinnati from Taiwan in the early 1980s. Once here, my siblings gravitated towards the sciences. I was the black sheep. I was in love with the humanities. So I didn’t go to M.I.T. — I went to Princeton, where I got a degree in philosophy. This, of course, worried my parents. They’d never met a philosopher with a job. Do you have any insight on why scientific careers are so attractive to new Americans? You don’t need to speak perfect English to do science. And there are job opportunities. Define neuroethics. It’s a kind of subspecialty of bioethics. Until very recently, the human mind was a black box. But here we are in the 21st century, and now we have all these new technologies with opportunities to look inside that black box — a little. With functional magnetic imaging, f.M.R.I., you can get pictures of what the brain is doing during cognition. You see which parts light up during brain activity. Scientists are trying to match those lights with specific behaviors. At the same time this is moving forward, there are all kinds of drugs being developed and tested to modify behavior and the mind. So the question is: Are these new technologies ethical? © 2012 The New York Times Company

Keyword: Miscellaneous
Link ID: 17614 - Posted: 12.18.2012

By Dwayne Godwin and Jorge Cham Dwayne Godwin is a neuroscientist at the Wake Forest University School of Medicine. Jorge Cham draws the comic strip Piled Higher and Deeper at © 2012 Scientific American

Keyword: Miscellaneous
Link ID: 17504 - Posted: 11.19.2012

Neuroscientists at the University of Ingberg have found a brain region that does absolutely nothing. Their research, presented at the annual Society for Neuroscience meeting, showed that a small region of the cortex located near the posterior section of the cingulate gyrus responded to ‘not one of our 46 experimental manipulations’. Dr. Ahlquist was rather surprised at the finding. “During a pilot study we noticed that this small section of the cortex did not show differential activity in any of our manipulations. Out of curiosity, we wanted to see whether it actually did anything at all. Over the months that followed we tried every we knew, with over 20 different participants. IQ tests, memory tasks, flashing lights, talking, listening, imagining juggling, but there was no response. Nothing. We got more desperate, so we tried pictures of faces, TMS, pictures of cats, pictures of sex, pictures of violence and even sexy violence, but nothing happened! Not even a decrease. No connectivity to anywhere else, not even a voodoo correlation. 46 voxels of wasted space. I know dead salmons that are more responsive. It’s an evolutionary disgrace, that’s what it is.” Some neuroscientists are disappointed by the regions’ lack of response: ‘This is exactly the type of cortical behavior that leads to this popular science nonsense about using only 10% of our brain. Frankly, I am outraged by this lazy piece of brain. It’s the cortical equivalent of a spare tyre. If anyone wants to have it lobotomized, I am happy to break out the orbitoclast and help them out. That’ll teach it.”

Keyword: Brain imaging
Link ID: 17464 - Posted: 11.07.2012

by Virginia Morell Alex, an African grey parrot who died 5 years ago and was known for his ability to use English words, also understood a great deal about numbers. In a new study in this month's Cognition, scientists show that Alex correctly inferred the relationship between cardinal and ordinal numbers, an ability that has not previously been found in any species other than humans. After learning the cardinal numbers—or exact values—of one to six, Alex was taught the ordinal values (the position of a number in a list) of seven and eight—that is, he learned that six is less than seven, and seven is less than eight. He was never taught the cardinal values of seven and eight—but when tested on this, he passed with flying colors, apparently inferring, for instance, that the sound "seven" meant six plus one. In the video above of one of these experiments, comparative psychologist Irene Pepperberg of Harvard University asks Alex to pick out the set of colored blocks that equal the number seven. Play the video to hear his answer. © 2010 American Association for the Advancement of Science.

Keyword: Intelligence; Evolution
Link ID: 17458 - Posted: 11.06.2012

By Cari Nierenberg The strange folds and furrows covering a Brazilian man's entire scalp was neither a funky new look nor a hipster trend. Rather the 21-year-old's bizarre looking scalp with its deep skin folds in a pattern said to resemble the surface of the brain is a sign of a rare medical condition known as cutis verticis gyrata. In this week's New England Journal of Medicine, two Brazilian doctors describe this young man's case and share a picture of its odd appearance. When he was 19, the skin on his scalp started to change. It grew thicker, forming many soft, spongy ridges and narrow ruts. Even his hair had an unusual configuration. It was normal in the furrows but sparser over the folds as is common for this strange scalp condition. No doubt, visits to the barber shop as well as washing his squishy scalp and combing his hair were peculiar experiences. Despite the extent of his scalp affected, "the patient did not have the habit of covering his head," with a hat, for instance, says Dr. Karen Schons a dermatologist at the Hospital Universitario de Santa Maria, who examined the patient and co-authored the case study. In fact, the case study reports that "the condition did not bother him cosmetically." © 2012

Keyword: Miscellaneous
Link ID: 17386 - Posted: 10.18.2012

Zoë Corbyn Conventional wisdom says that most retractions of papers in scientific journals are triggered by unintentional errors. Not so, according to one of the largest-ever studies of retractions. A survey1 published in Proceedings of the National Academy of Sciences has found that two-thirds of retracted life-sciences papers were stricken from the scientific record because of misconduct such as fraud or suspected fraud — and that journals sometimes soft-pedal the reason. The survey examined all 2,047 articles in the PubMed database that had been marked as retracted by 3 May this year. But rather than taking journals’ retraction notices at face value, as previous analyses have done, the study used secondary sources to pin down the reasons for retraction if the notices were incomplete or vague. These sources included investigations by the US Office of Research Integrity, and evidence reported by the blog Retraction Watch. The analysis revealed that fraud or suspected fraud was responsible for 43% of the retractions. Other types of misconduct — duplicate publication and plagiarism — accounted for 14% and 10% of retractions, respectively. Only 21% of the papers were retracted because of error (see ‘Bad copy’). Earlier studies had found that the percentage of retractions attributable to error was 1.5–3 times higher2–4. “The secondary sources give a very different picture,” says Arturo Casadevall, a microbiologist at Yeshiva University in New York, and a co-author of the latest study. “Retraction notices are often not accurate.” © 2012 Nature Publishing Group

Keyword: Miscellaneous
Link ID: 17322 - Posted: 10.02.2012

Clint Witchalls James R. Flynn is Professor Emeritus at the University of Otago, New Zealand. Flynn researches intelligence and is best known for the discovery that, over the past century, IQs have been rising at a rate of about 3 points per decade (the Flynn-effect). In advance of his new book on the subject, Clint Witchalls asked him about this and some of Professor Flynn's more recent research findings: Clint Witchalls: How has our way of thinking and of solving problems changed over the past century? James R. Flynn: Today we take it for granted that using logic on the abstract is an ability we want to cultivate and we are interested in the hypothetical. People from 1900 were not scientifically oriented but utilitarian and they used logic, but to use it on the hypothetical or on abstractions was foreign to them. Alexander Luria [a Soviet psychologist] went to talk to headmen in villages in rural Russia and he said to them: "Where there is always snow, bears are white. At the North Pole there is always snow, what colour are the bears there?" And they said: "I've only seen brown bears." And he said: "What do my words convey?" And they said: "Such a thing as not to be settled by words but by testimony." They didn't settle questions of fact by logic, they settled them by experience. Your research found that we have gained 30 points on IQ tests in a century. What is the reason? The ultimate cause of why IQs are rising is the industrial revolution. The proximate cause is how our minds differ from people in 1900 when in the test room. And the intermediate causes, of course, are more cognitively demanding work roles, more cognitively demanding leisure, more formal schooling, and smaller families. ©

Keyword: Intelligence; Learning & Memory
Link ID: 17307 - Posted: 09.27.2012

By Melissa Healy Los Angeles Times Measuring human intelligence may be controversial and oh-so-very-tricky to do. But like obscenity, we think we know it when we see it. A new study, however, demonstrates a more rigorous way to see and measure differences in intelligence between individuals. It finds that connectedness among the brain's disparate regions is a key factor that separates the plodding from the penetrating. As many researchers have long suspected, intelligence does have a "seat" in the human brain: an area just behind each of the temples called the lateral prefrontal cortex. But researchers writing in the journal Neuroscience found that human behavior that is exceptionally flexible, responsive and capable of navigating complexity requires something beyond a strong and active prefrontal cortex: strong and agile runners must link that seat to brain regions involved in perception, memory, language and mobility. The researchers estimate that the strength of those connections, as measured when subjects rested between mental tasks, explains about 10% of differences in intelligence among individuals. That makes this measure an even better predictor of intelligence than brain size -- a measure that scientists believe may explain about 7% of the variation in intelligence among individuals. To detect this relationship, the Neuroscience study compared functional magnetic resonance imaging (fMRI) brain scans of 78 men and women between 18 and 40 years old with those subjects' performance on tests of cognitive performance that required "fluid intelligence" and "cognitive control." Subjects, for instance, were asked to count backwards by, say, nine, or to watch a series of visual images and then indicate whether a single image shown had been among them. Copyright 2012

Keyword: Intelligence; Brain imaging
Link ID: 17117 - Posted: 08.04.2012

By Maria Konnikova It’s 1879, and psychology is just about to be born. The place: the University of Leipzig. The birth parent: Wilhelm Wundt. The deed: establishing the first official university laboratory for the study of psychology, an event taken by many as the line that marks unofficial explorations from empirical, accepted science. The laboratory has four rooms and a handful of students. By the early 1880s, it will grow to an astounding six rooms—and a total of 19 students. In 1883, it will award its first doctoral degree, to the first of Wundt’s advisees, Max Friedrich, on the topic of the time-course of individual psychological processes. That same year will see the publication of the first issue of the Journal Philosophische Studien, the first journal of experimental psychology, established—fittingly—by none other than Wundt. From that point on, the future of the discipline will be assured: psychology will survive, and perhaps even flourish, with the dawn of the new century. It will not be just another experiment gone wrong. That, at least, is the most straightforward story. It’s difficult to pinpoint a date for the birth of Psychology as such. That 1879 laboratory is but one contender, and Wundt, but one possible father. But just think of how many paved the way for Wundt’s achievements. Is it fair to call him the start, or is he rather more of a point of coalescence (if that)? And how far back must we go, if we’re to be really fair? © 2012 Scientific American,

Keyword: Miscellaneous
Link ID: 17114 - Posted: 08.01.2012

by Michael Balter Many children (and adults) have heard Aesop's fable about the crow and the pitcher. A thirsty crow comes across a pitcher partly filled with water but can't reach the water with his beak. So he keeps dropping pebbles into the pitcher until the water level rises high enough. A new study finds that both young children and members of the crow family are good at solving this problem, but children appear to learn it in a very different ways from birds. Recent studies, particularly ones conducted by Nicola Clayton's experimental psychology group at the University of Cambridge in the United Kingdom have shown that members of the crow family are no birdbrains when it comes to cognitive abilities. They can make and use tools, plan for the future, and possibly even figure out what other birds are thinking, although that last claim is currently being debated. A few years ago, two members of Clayton's group showed that rooks can learn to drop stones into a water-filled tube to get at a worm floating on the surface. And last year, a team led by Clayton's graduate student Lucy Cheke reported similar experiments with Eurasian jays: Using three different experimental setups, Cheke and her colleagues found that the jays could solve the puzzle as long as the basic mechanism responsible for raising the water level was clear to the birds. To explore how learning in children might differ from rooks, jays, and other members of the highly intelligent crow family, Cheke teamed up with a fellow Clayton lab member, psychologist Elsa Loissel, to try the same three experiments on local schoolchildren aged 4 to 10 years. Eighty children were recruited for the experiments, which took place at their school with the permission of their parents. © 2010 American Association for the Advancement of Science

Keyword: Intelligence; Evolution
Link ID: 17092 - Posted: 07.26.2012

by Elizabeth Pennisi OTTAWA—With big brains comes big intelligence, or so the hypothesis goes. But there may be trade-offs as well. Humans and other creatures with large brains relative to their body size tend to have smaller guts and possibly fewer offspring. Scientists have debated for decades whether the two phenomena are related. Now a team of researchers says that they are—and that big brains do indeed make us smart. The finding comes thanks to an unusual experiment reported here yesterday at the Evolution Ottawa evolutionary biology meeting in which scientists shrank and grew the brains of guppies over several generations. "This is a real experimental result," says David Reznick, an evolutionary biologist at the University of California, Riverside, who was not involved in the study. "The earlier results were just correlations." Researchers first began to gather evidence that big brains were advantageous after 19th century U.S. biologist Hermon Bumpus examined the brains of sparrows, some of whom had succumbed in a blizzard and some of whom survived. The survivors had relatively larger brains. More recently, evolutionary biologist Alexei Maklakov from Uppsala University in Sweden found evidence that songbirds that colonize cities tend to have larger brains relative to their body size than species still confined to the countryside. The challenge of urban life might require bigger brains, he and his colleagues concluded last year in Biology Letters. Yet in humans and in certain electric fish, larger brain size seems to have trade-offs: smaller guts and fewer offspring. That's led some scientists to suggest there are constraints on how big brains can become because they are expensive to build and maintain. © 2010 American Association for the Advancement of Science.

Keyword: Evolution; Intelligence
Link ID: 17026 - Posted: 07.11.2012