Happy to Be Here... (Heller)

My thanks to Adam for inviting me to guest-blog.  I normally blog on international-law issues at Opinio Juris, so it's great to branch out for a couple of weeks. 

I have to admit at the outset that I am something of a dilettante when it comes to neuroethics and law, although I do have a very strong interest in the cognitive psychology of jury decision-making.  I am particularly interested in Kahneman and Tversky's simulation heuristic: the idea that the ability to imagine a scenario is positively correlated with one's assessment of its likelihood.  It's my suspicion that simulation plays a much larger role in jury decision-making than legal scholars, still far too enthralled with Bayesian analysis than is good for them, have recognized -- an idea I explore at length in a recent essay in the Michigan Law Review entitled "The Cognitive Psychology of Circumstantial Evidence."  (It's available here.)  Oversimplifying dramatically, the essay argues that jurors' skepticism well-documented reluctance to convict in cases based on circumstantial forensic evidence, and their concomitant tendency to overconvict in cases based on direct evidence like eyewitness identifications and confessions, can be explained by the fact that direct evidence is far easier to visualize -- i.e., simulate -- than circumstantial evidence.  I am currently working on a companion essay that uses the simulation heuristic, via research into projection and prototyping, to argue that some criminal defenses are far more likely to succeed than others.  Alas, my guest-blogging will end long before it is finished...

Now that the self-aggrandizing introduction is out of the way, I thought I would inaugurate my stint here by mentioning a fascinating -- and amusing -- study that found that young chimps have better short-term memory than college students:

Think you're smarter than a fifth-grader? How about a 5-year-old chimp? Japanese researchers pitted young chimps against human adults in tests of short-term memory, and overall, the chimps won.

That challenges the belief of many people, including many scientists, that "humans are superior to chimpanzees in all cognitive functions," said researcher Tetsuro Matsuzawa of Kyoto University.

"No one can imagine that chimpanzees — young chimpanzees at the age of 5 — have a better performance in a memory task than humans," he said in a statement.

Matsuzawa, a pioneer in studying the mental abilities of chimps, said even he was surprised. He and colleague Sana Inoue report the results in Tuesday's issue of the journal Current Biology.

One memory test included three 5-year-old chimps who'd been taught the order of Arabic numerals 1 through 9, and a dozen human volunteers.

They saw nine numbers displayed on a computer screen. When they touched the first number, the other eight turned into white squares. The test was to touch all these squares in the order of the numbers that used to be there.

Results showed that the chimps, while no more accurate than the people, could do this faster.

One chimp, Ayumu, did the best. Researchers included him and nine college students in a second test.

This time, five numbers flashed on the screen only briefly before they were replaced by white squares. The challenge, again, was to touch these squares in the proper sequence.

When the numbers were displayed for about seven-tenths of a second, Ayumu and the college students were both able to do this correctly about 80 percent of the time.

But when the numbers were displayed for just four-tenths or two-tenths of a second, the chimp was the champ. The briefer of those times is too short to allow a look around the screen, and in those tests Ayumu still scored about 80 percent, while humans plunged to 40 percent.

That indicates Ayumu was better at taking in the whole pattern of numbers at a glance, the researchers wrote.

As most readers of this blog will likely know, scientists recently concluded that human DNA differs from chimp DNA by more than 5%, not by the 1.5% of conventional wisdom.  Predictably, right-wingers have seized upon the new findings to trumpet human superiority over their monkey cousins.  Is it too facile to suggest that the memory study may actually indicate that it is we, not the chimps, who received the short end of the genetic stick?

Comments

[Adam Kolber]

Your project sounds really interesting! Thanks for posting about it.

[Magnus]

I mean, why could animals not be able to beat us in certain mental tasks? They do it in many physical activities.

I made a site where one can try that test:

http://www.chimp-test.com/

...and even though it shows the digits slightly longer than in the original test, it is still very difficult to come up to the level of 80% success rate, which was the level of those chimps if I remember correctly.

Regards,
Magnus