Comparative Psychology
developingintelligence | October 16, 2007Although most humans are right-handed, other animals don't seem to show a similar motoric asymmetry. As Corballis mentions in his 2003 BBS article, even the great apes - our closest relatives in the animal kingdom - tend not to show a right-hand preference unless raised in captivity, suggesting handedness is learned through imitation of caregivers. So why should humans be the only species to show clear manual asymmetry, 9:1 in favor of righties?
While manual asymmetry may be unique to humans, cerebral asymmetry is not. Corballis reviews how animals as diverse as frogs, birds, mice, rats,…
mixingmemory | August 17, 2007Crows are smart. Really smart. But just how smart are they? Studying non-human primates, particularly gorillas, orangutans, and chimpanzees, researchers have shown that they're capable of what's called meta-tool use, or using one tool with another tool (I've mostly seen it defined as using one tool to modify or improve another tool, but more on definitions in a bit), but it's not always something these primates do readily. Monkeys (macaques, e.g.) are much less likely to display meta-tool use. Meta-tool use is difficult because it requires behaving in a way that isn't directly linked to a…
developingintelligence | June 28, 2007In 1948, Alan Turing wrote: "An unwillingness to admit the possibility that mankind can have any rivals in intellectual power occurs as much amongst intellectual people as amongst others: they have more to lose." Accordingly, comprehensive comparisons between the intellectual powers of great apes and humans are rare - perhaps because we feel safe in assuming that the human intellect is superior to that of other primates. But recent work suggests this assumption may not be entirely sound, as described below.
For example, a recent New Scientist article (via NeuroEthics) contains a provocative…
mixingmemory | June 5, 2007
Over the last couple decades there's been a pretty heated debate about which, if any, nonhuman animals possess a "theory of mind," that is, the ability to think about what others are thinking. Much of the research bearing on this debate has used false belief tasks. There are many variants, but the standard false belief task goes something like this. One experimenter puts something interesting (e.g., food or a toy) in one of two boxes while another experimenter and the subject (a child or a primate, usually) watches. The observing experimenter then leaves the room. While that experimenter is…
developingintelligence | April 25, 2007A lack of clear definitions for terms like "intelligence" and "consciousness" plagues any serious discussion of those concepts. A recent article by Seth, Baars & Edelman argues for a core set of 17 properties that are characteristic of consciousness, and could be used in the "diagnosis" of consciousness in humans and other animals.
Property 1: "Irregular" patterns of brain activity
Electrical oscillations occuring between 20 and 70 times per second are common in awake humans, but epilepsy, sleep, anesthesia and some forms of brain damage are accompanied by the dominance of highly regular…
developingintelligence | April 17, 2007Your body's bilateral symmetry statistically predicts your health, probability of schizotypy and depression, number of sexual partners, and resting metabolic rate (particularly if you are male). Bodily symmetry may reflect "developmental stability" - i.e., influences like disease, mutation and stress may cause a developmental divergence from DNA's symmetric blueprint. Not only do individuals differ in their environmental exposure to these things, but also in their sensitivity to them: a recent Intelligence article claims that "some individuals grow adaptive phenotypes under almost any…
developingintelligence | April 5, 2007"To understand ourselves, we must embrace the alien." - PZ Meyers
One difficulty in understanding consciousness is the fact that we know of only one species that certainly possesses it: humans. A new article by Jennifer Mather suggests that octopi may also possess consciousness, despite the vastly different architecture of their brain. If two very different neural architectures can both support forms of advanced cognition, then the similarities between them may help clarify the computational requirements for intelligent behavior.
Octopus brains are striking different from those in primates…
mixingmemory | March 14, 2007I'm sure you've all long forgotten about the framing project that I discussed on this blog late last year, but in case someone out there remembers it, I wanted to give you an update. I still want to collect the category norms that I discussed. That is, I want to have people list features of political concepts like abortion, social security, war, etc., along with concepts related to Lakoff's framing analysis such as family, nation, and the like (if you'd like to help me write the code for this, let me know). However, not long after I discussed the project on this blog, my perspective changed…
mixingmemory | February 22, 2007In a comment to the last post, "Korax" mentions a paper published online in Current Biology this week on chimpanzee tool use. The tool use described in this paper is, as far as I can tell, as or more complex than any previously witnessed in chimps. Here's the abstract:
Although tool use is known to occur in species ranging from naked mole rats [1] to owls [2], chimpanzees are the most accomplished tool users. The modification and use of tools during hunting, however, is still considered to be a uniquely human trait among primates. Here, we report the first account of habitual tool use during…
mixingmemory | February 14, 2007You've probably already come across this story, but just in case:
Oldest chimp tools found in West Africa
Apes could have passed down skills for thousands of years.
In the West African rainforest, archaeologists have found ancient chimpanzee stone tools thousands of years older than the previous oldest finds in the same area. The discovery suggests that chimps may have passed cultural information down the generations for more than 4,000 years.
I'm no archeologist, and since the paper doesn't seem to be on the PANAS website, as the Nature article says it should be, I couldn't evaluate the…
developingintelligence | January 4, 2007There are many theories of how human behavior came to differ so profoundly from that of even our closest primate relatives - language, recursion, theory of mind, and enhanced working memory are just a few of the "critical components" that have been proposed as enabling human intelligence. A very different perspective, advocated by Tomasello and Carpenter, suggests that it is simply humans' extreme propensity for social interaction that is at the core of the evolution of human intelligence.
In their article, Tomasello and Carpenter focus on four effects of this social tendency, which they…
developingintelligence | January 2, 2007It seem reasonable that evolution might select for adaptive behaviors by increasing the relative size of particular brain regions that support those behaviors; for example, bats might have an enlarged auditory cortex since they navigate with echolocation. To some extent this does happen, but such differences are often apparent only after controlling for a much larger source of variance: changes in brain size that correlate with changes in body size - and the implications of this fact are wide-reaching.
As Barbara Finlay and coauthors wrote in this 2001 Behavioral and Brain Sciences article,…
mixingmemory | November 7, 2006By now you've probably all heard about the paper published by Plotnik, de Waal, and Reiss in the Proceedings of the National Academy of Sciences in late October titled "Self-recognition in an Asian elephant." I suspect that for people who study elephants, the results described in that paper come as no surprise. Researchers have been testing elephants on measures of self-awareness for a while, because they seemed like a good candidate. Still, the conclusion, stated in the title of the paper, is probably a bit premature. To understand why, though, it's important to understand the methods used…
mixingmemory | September 9, 2006Over the years I'd heard that, lurking in the basements of psychology departments at various universities throughout the world, there are psychologists studying music cognition, but until the publication of a special issue of the journal Cognition, I hadn't really paid any attention to them. That issue (especially Ray Jackendoff's "The capacity for music: What is it, and what's special about it?") got me interested in the topic, though, not so much because it can tell us much about cognition in general, but because the experiments are usually pretty cool. So, I've been on the lookout for…