Animal Intelligence and Evolution of the Human Mind

living organism Intelligence and Evolution of the homoity MindThe world judgement omits egregious characteristics- much(prenominal) as relative or compulsory size-that might account for cosmos passkey intellect.Researchers devour found some clues to humanitys aptitude on a smaller scale, much(prenominal)(prenominal) as much than(prenominal) neurons in our creative thinkers outermost layer.Human cognition may be best likened to an upgrade of the cognitive capacities of dehumanized primates rather than an exceptionally advanced form of cognition.Subtle refinements in forefront architecture, rather than heroic-scale alterations, make us smarter than other animals.As far as we know, no dog whoremonger compose music, no dolphin can speak in rhymes, and no parrot can solve equations with two unknowns. Only gentlemans gentleman can perform such intellectual feats, presumably beca apply we argon smarter than all other animal species-at least(prenominal) by our own de finition of word.Of course, intelligence must emerge from the workings of the three-pound mass of wetw ar packed inside our skulls. Thus, researchers assimilate tried to identify preposterous features of the human consciousness that could account for our superior intellectual abilities. solely, anatomically, the human understanding is very similar to that of other primates beca workout humans and chimpanzees sh atomic number 18 an ancestor that walked the earth less than s fifty-fifty million years ago.Accordingly, the human headspring contains no highly conspicuous characteristics that might account for the species cleverness. For instance, scientists choose failed to visit a correlation between absolute or relative encephalon size and acumen among humans and other animal species. Neither have they been able to discern a parallel between wits and the size or existence of specific roles of the brain, excepting perchance Brocas orbit, which governs speech in people. The lack of an obvious structural correlate to human intellect jibes with the idea that our intelligence may non be wholly unequaled studies are revelation that chimps, among respective(a) other species, possess a diversity of humanlike amicable and cognitive skills.Nevertheless, researchers have found some microscopic clues to humanitys aptitude. We have more neurons in our brains intellectual cortex (its outermost layer) than other mammals do. The insulation slightly nerves in the human brain is withal thicker than that of other species, change the nerves to direct signals more rapidly. Such biological subtleties, along with behavioral ones, suggest that human intelligence is best likened to an upgrade of the cognitive capacities of anthropoidal primates rather than an exceptionally advanced form of cognition.Smart SpeciesBecause animals cannot canvas or speak, their aptitude is difficult to discern, much less measure. Thus, comparative psychologists have invented behav ior-based tests to assess birds and mammals abilities to learn and reappendage, to poke numbers and to solve practical problems. Animals of various stripes- only especially nonhuman primates-often earn high marks on such action-oriented IQ tests. During World War I, German psychologist Wolfgang Khler, for font, showed that chimpanzees, when confronted with fruit temporary removal from a high ceiling, devised an ingenious way to get it they stacked boxes to deadlock on to reach the fruit. They also constructed long sticks to reach viands right(prenominal) their enclosure. Researchers now know that great apes have a sophisticated instinct of tool use and construction.Psychologists have used such behavioral tests to finish up similar cognitive feats in other mammals as well as in birds. Pigeons can discriminate between male and female faces and among paintings by unlike artists they can also group pictures into categories such as trees, selecting those belong to a category by p ecking with their beaks, an action that often brings a food reward. Crows have intellectual capacities that are overturning conventional wisdom intimately the brain.behavioural ecologists, on the other hand, prefer to judge animals on their street smarts-that is, their index to solve problems relevant to survival in their natural habitats-rather than on their test-taking talents. In this view, intelligence is a cluster of capabilities that evolved in response to particular environments. round scientists have further proposed that moral or behavioral flexibility, the ability to suffice up with novel solutions to problems, is another good measure of animal intellect. Among birds, dark-green herons occasionally throw an object in the water to lure unusual fish-a trick that, ornithologists have notice, has been reinvented by groups of these animals living in distant locales. fifty-fifty fish display remarkable practical intelligence, such as the use of tools, in the wild. Cichl id fish, for instance, use leaves as baby carriages for their egg masses.Animals also can display humanlike social intelligence. Monkeys engage in deception, for example dolphins have been known to care for another injured pod member (displaying empathy), and a giant star or porpoise may recognize itself in the mirror. evening some fish exhibit subtle kinds of social skills. Behavioral ecologist Redouan Bshary of the University of Neuchtel in Switzerland and his colleagues described one such case in a 2006 paper. cadaveric fish such as the so-called cleaner wrasse (Labroides dimidiatus) cooperate and overthrow parasites from the skin of other fish or feed on their mucus. Bsharys squad found that bystander fish spent more time next to dry cleaners the bystanders had observed being cooperative than to other fish. human race, the authors note, tend to notice altruistic behavior and are more willing to help do-gooders whom they have observed doing favors for others. Similarly, cle aner wrasses observe and evaluate the behavior of other finned ocean denizens and are more willing to help fish that they have seen assisting third parties.From such studies, scientists have constructed evolutionary hierarchies of intelligence. Primates and cetaceans (whales, dolphins and porpoises) are considered the smartest mammals. Among primates, humans and apes are considered cleverer than monkeys, and monkeys more so than prosimians. Of the apes, chimpanzees and bonobos rank above gibbons, orangutans and gorillas. Dolphins and sperm whales are supposedly smarter than nonpredatory whalebone whales such as blue whales. Among birds, scientists consider parrots, owls and corvids (crows and ravens) the brightest. Such a pecking invest argues against the idea that intelligence evolved along a single path, culminating in human acumen. Instead intellect seems to have emerged independently in birds and mammals and also in cetaceans and primates.Heavy Thoughts?What about the brain mi ght underlie these parallel paths to abstrusity? One candidate is absolute brain size. Although many studies have associate brain mass with variations in human intelligence see High-Aptitude Minds, by Christian Hoppe and Jelena Stojanovic, size does not always correlate with smarts in different species. For example, clever small animals such as parrots, ravens, rats and relatively diminutive apes have brains of modest proportions, whereas some spectacular animals such as horses and cows with large brains are comparatively dim-witted. Brain bulk cannot account for human intelligence either At eight to nine kilograms, sperm and killer whale brains far outweigh the 1.4 kilograms of neural tissue inside our heads. As to a great extent as five kilograms, elephant brains are also much chunkier than ours.Relative brain size-the ratio of brain to body mass-does not provide a substantive explanation for interspecies differences in smarts either. Humans do compare favorably with many me dium and large species our brain makes up approximately 2 percent of our body weight, whereas the blue whales brain, for instance, is less than one 100th of a percent of its weight. But some tiny, not terribly bright animals such as shrews and squirrels win out in this measure. In general, small animals mess up relatively large brains, and large animals harbor relatively small ones. Although absolute brain mass increases with body weight, brain mass as a proportion of body mass tends to decrease with rising body weight. some other cerebral yardstick that scientists have tried to tie to intelligence is the leg of encephalization, measured by the encephalization quotient (EQ). The EQ expresses the extent to which a species relative brain weight deviates from the average in its animal class, say, mammal, bird or amphibian. here the human brain tops the list it is seven to eight time larger than would be expected for a mammal of its weight. But EQ does not parallel intellect perfect ly either gibbons and some civet cat monkeys have higher EQs than the more intelligent chimpanzees do, and even a a couple of(prenominal) prosimians-the earliest evolved primates alive today-have higher EQs than gorillas do.Or perhaps the size of the brains outermost layer, the cerebral cortex-the seat of many of our cognitive capacities-is the key. But it turns out that the dimensions of the cerebral cortex depend on those of the entire brain and that the size of the cortex constitutes no better arbiter of a superior mind. The same is true for the prefrontal cortex, the hub of reason and action planning. Although some brain researchers have claimed in the past that the human prefrontal cortex is exceptionally large, recent studies have shown that it is not. The size of this structure in humans is comparable to its size in other primates and may even be relatively small as compared with its counterpart in elephants and cetaceans.The lack of a big measure of the human brain that c ould explain our performance may fall the idea that human intellect may not be wholly inimitable. Apes, after all, understand cause and effect, make and use tools, produce and comprehend language, and lie to and imitate others. These primates may even possess a theory of mind-the ability to understand another animals mental state and use it to guide their own behavior. Whales, dolphins and even some birds boast some of these mental talents as well. Thus, adult humans may simply be more intuitive and facile with tools and language than other species are, as opposed to possessing unique cognitive skills.NetworkingFittingly, researchers have found the best correlates for intelligence by looking at a much smaller scale. Brains consist of nerve cells, or neurons, and supporting cells called glia. The more neurons, the more extensive and more productive the neural networks can be-and those networks determine varied brain functions, including perception, memory, planning and thinking. L arge brains do not automatically have more neurons in fact, neuronal concentration generally decreases with increasing brain size because of the additional glial cells and smear vessels needed to support a big brain.Humans have 11.5 jillion cortical neurons-more than any other mammal, because of the human brains high neuronal density. Humans have only about half a billion more cortical neurons than whales and elephants do, however-not enough to account for the significant cognitive differences between humans and these species. In addition, however, a brains information-processing capacity depends on how fast its nerves conduct electrical impulses. The most rapidly conducting nerves are swathed in sheaths of insulation called myelin. The thicker a nerves myelin sheath, the faster the neural impulses travel along that nerve. The myelinated nerves in the brains of whales and elephants are demonstrably thinner than they are in primates, suggesting that information travels faster in t he human brain than it does in the brains of nonprimates.What is more, neuronal messages must travel longer distances in the relatively large brains of elephants and whales than they do in the more compact human brain. The resulting boost in information-processing speed may at least partly explain the dissimilarity in aptitude between humans and other big-brained creatures.Among humans cerebral advantages, language may be the most obvious. Various animals can use up complex messages to other members of their species they can communicate about objects that are not in sight and relay information about individuals and events. Chimpanzees, gorillas, dolphins and parrots can even understand and use human speech, gestures or symbols in constructions of up to about three words. But even after years of training, none of these creatures develops vocal skills more advanced than those of a three-year-old child.In humans, grammar and vocabulary all but explode at age three. This timing corre sponds with the development of Brocas speech area in the left frontal lobe, which may be unique to humans. That is, scientists are unsure whether a direct precursor to this speech region exists in the nonhuman primate brain. The absence of an intricately wired language region in the brains of other species may explain why, of all animals, humans completely have a language that contains complex grammar. Researchers date the development of human grammar and syntax to between 80,000 and 100,000 years ago, which makes it a relatively recent evolutionary advance. It was also one that probably greatly enhanced human intellect.