Insight in Animals Lecture 8 Psych 1090
Insight is complex: • Refers to mental visualizations used to determine the best of alternate choices to solving a problem • Occurs not with respect to physical features that are obvious (e.g., nest sites), but features that must be imagined • That is, involves imagining the outcomes of many motor patterns or choices withoutever having experienced them
And, once the outcomes are imagined, involves choosing what to do, based on what is theoretically imagined Thus insight is the antithesis of costly trial-and-error learning Furthermore, insight must not be cued by other events in the surroundings that might trigger memories of related behavior
Insight may, however, involve integrating widely differing bits of previously learned information in an unconscious manner….. although some researchers argue that insight requires consciousness at least in the sense of conscious choice among outcomes
In any case, insight requires that a subject • project images forward in a progression • act based to some extent on general knowledge but not experience • understand the essential relationships of the situation • and have a specific goal in mind
In addition, demonstrating insight means ruling out • not only any form of direct learning, • but also any form of prewired, innate behavior
Thus, one must examine problems that the animal cannot have encountered as a selective force in evolution or through individual experience
The classic cases of insight, involving Köhler’s chimpanzees, of joining sticks and stacking boxes to get food….
Has been criticized because animals • may have seen technicians performing some of these behavior patterns or • the number of choices available to the animals were too small (i.e., only one way sticks could fit together)
So, researchers want to examine insight in controlled situations…. and, preferably, in animals that are less like humans than apes to avoid over-interpretation of data…. but whose lifestyles would accommodate insightful behavior
Heinrich chose to study insight in ravens because these birds live in an environment that would encourage such behavior…. One characterized by • unpredictability of resources and • the need to predict the behavior of others
Much of ravens’ hunting requires the ability to determine where prey will go next…. e.g., small mammals, birds, reptiles that exhibit escape maneuvers So that they need to demonstrate at least a learned capacity to predict the outcome of a given situation
Many of their social interactions require them to determine what either a conspecific or an allospecific hunting partner (e.g., a wolf) will do next Failure to act appropriately could have serious, if not fatal, consequences
They steal food from other hunters which again suggests that they must learn about those hunters’ behavior patterns And they cooperate among themselves at various caches
Ravens seem to exhibit intelligent, if not insightful, behavior in nature…. One was observed to tackle a huge source of suet by hacking a groove making dozens of consecutive beak blows in a precise line-- thus slicing off a piece it could carry
Others have been observed to throw stones at nest intruders And to wait to move until at least 5 of 6 hunters had left a blind; if fewer than 5 entered, birds didn’t move til all had departed….
But these behavior patterns could have been learned…. So Heinrich developed a task, string pulling to obtain food, that they would never come across in the wild
In particular, this task required a knowledge of ‘means-end’ behavior which is not the same as simple association…if I do X, Y happens Understanding means-ends behavior implies the ability to see a novel situation
Recognize the goal and how to achieve the goal based on the qualities of the situation and the qualities of the elements that constitute the situation Not all species succeed
Studies with some songbirds showed that they were actually trained on the task in a stepwise manner And for some species, previous experience turns out to be important
Ravens don’t seem to deal with situations in which they have to, for example, pull vines to get berries BUT…they can grasp objects with their feet and beaks, so string-pulling would be a possible task to solve
The idea was to determine if • meat was suspended low enough that they couldn’t simply reach down and pull it up, • or break off chunks and fly away • could they reach down, pull up string, hold onto string w/ their feet, release their beak, and repeat the maneuver as many times as necessary to get the meat?
This behavior meant integrating a large number of different motions in a very precise order to solve a problem never previously encountered and to do it without trial-and-error learning
Too, if the birds succeeded on this task, it could be made more complex to test related cognitive— and possibly insightful—abilities
The experiment was not simple… Wild birds flew away from meat suspended on the string Adult ravens tend to be neophobic, avoiding any situation that has an unfamiliar component which makes testing in novel circumstances almost impossible
Wild-caught birds that had lived in an aviary for a year weren’t much better… Only one of 14 aviary birds approached and pulled up the meat in <1 minute Only three birds followed the first’s lead over the course of a few days
In a second test, with a wild-caught, caged group, 3 of 13 performed the behavior correctly… In a bunch of 4 month old juveniles, not yet neophobic, 4 attempted the task but failed….. But 2 yrs later, 3 of these 4 birds succeeded w/out intervening trials
So, Heinrich decided to test some hand-reared ravens… That way, he could make sure what experiences the birds had already had These birds were ~ 1.5 yrs old and into the age where neophobia could be a problem
He used birds that had never seen string before, but were used to people, so having experimenter observe them would not affect the experiments and were also used to small changes in their environments, plus probably things like hoses
One bird pecked at the string and actually tried yanking the string But didn’t get the idea of raising the string Then jumped from below and managed to tear off some tiny bit of meat
Other birds tried to fly up and get the meat from below, but could not tear off the hard, dried food that was used One bird approached the string from the perch, pecked at it and yanked once, then left the site Then, 6 hrs later…this bird completed the entire string-pulling maneuver!
Here’s a clip of one of my birds performing the task, so you can remember what is involved…
Clearly, that raven demonstrated insight…. It had observed the situation, gone away, and, in the 6 hr interim, somehow figured out what it would have to do to succeed… And without further experimentation, except in terms of mental representation
Four of the other five ravens in the group succeeded in the same way… They had seen the first bird succeed, and one copied the technique, of pulling string along the perch so they might be imitating or emulating that bird’s behavior
We’ll talk about the difference in imitation and emulation in detail in another lecture But emulation is copying the goal without necessarily copying the action Imitation is copying both…
But what level of insight was shown? Did the birds actually understand the physics of the situation? More experiments were needed to test out the details of what the birds did or didn’t know
Interestingly, crows didn’t succeed on these experiments but, as we’ll see, two types of parrots—Greys and keas—did making one wonder about exactly what cognitive skills are involved… In any case, Heinrich kept testing…
For example, if the meat at the bottom of the string was very large… a sheep’s head that the birds already knew they couldn’t lift it from prior experience…. would they still attempt the task or would they go for the biggest bit?
No bird chose the 2kg portion; all chose the small piece Of course, because the birds had had experience with the sheep head—not salami—on the ground, maybe they expected more sheep head later without having to work at it
And simply chose on the basis of expectation and ease of access The issue with all these studies is that one can likely never totally rule out alternative explanations but must keep trying to do so with additional experiments
Of interest, however, was that birds seemed to expect that strings held meat…. Strings always did hold meat and the birds had no reason to expect otherwise Again, what did they know about the situation?
So, when given a choice between a string with a rock and one with meat, they would make one or two tugs before switching to the meat-laden string… They never persisted with the wrong string, but still made ~10-20 errors before learning to look down first!
Were they really being stupid? Or just didn’t bother because the cost of making an error was so low? Only way to tell was to make the task a bit more difficult…
Now that birds had learned to look, could they go to a three-choice test where one string had nothing? The birds had never had seen a new colored string
Most birds eventually figured out that they had to go to the new string…. they made fewer errors than they had made with the stone versus meat task…. but not all looked down at first
Thus there was some aspect of learning, rather than only insight, involved in the behavior…. But now that the birds had learned to look, could they understand causality and connection? What if the experimenter crossed the strings having the meat and the stone?
Were birds just pulling on string above meat, or on string to which meat was attached? Results depended upon how far apart the objects were displaced
When items were displaced only a few cm, most of the birds chose the correct string But when the distance was increased to about 40 cm, Three birds failed—on over 79 trials!
Only one bird got it right, 17 times out of 21…. Which shows that the ability to understand the situation is inherently possible in ravens… although not at all widespread
What would happen if the birds now saw a new string? Would they be confused because it never had meat? Nope…they did better, 32 of 33 trials correct….these were different birds from the earlier task w/ colored strings