By the early 1900s the field of animal behavior had split into two majorbranches. One branch, ethology, developed primarily in Europe. To ethologists,what is striking about animal behaviors in that they are fixed and seeminglyunchangeable? For example, kittens and puppies play in characteristic butdifferent ways. Present a kitten with a ball of yarn and invariably it drawsback its head and bats the yarn with claws extended. Kittens are generallysilent as they play, and their tails twitch. Puppies, by contrast, are mostlikely to pounce flat-footed on a ball of yarn. They bit and bark and theirtails wag. Ethologists came to believe that ultimately even the most complexanimal behaviors could be broken down into a series of unchangeablestimulus/response reactions. They became convinced that the details of thesepatterns were as distinctive of a particular group of animals as were anatomicalcharacteristics. For well over half a century, their search for and descriptionof innate patterns of animal behavior continued.
Meanwhile, mainly in North America, the study of animal behavior took adifferent tack, developing into comparative behavior. Of interest to comparativebehaviorists was where a particular came from, that is, its evolutionaryhistory, how the nervous system controlled it, and the extent to which it couldbe modified. In 1894, C. Lloyd Morgan, an early comparative behaviorist,insisted that animal behavior be explained as simply as possible withoutreference to emotions or motivations since these could not be observed ormeasured. In Morgan’s research, animals were put in simple situations, presentedwith an easily described stimulus, and their resultant behaviordescribed.
The extension to animals of behaviorism—the idea that the study of behaviorshould be restricted to only those elements that can be directly observed—was animportant development in comparative behavior. Studies of stimulus/response andthe importance of simple rewards to enforce and modify animal behavior werestressed. Not surprisingly, comparative behaviorists worked most comfortably inthe laboratory. Comparative behaviorists stressed the idea that animal behaviorcould be modified, while their ethologist colleagues thought it was innate andunchangeable. Inevitably, the two approaches led to majordisagreements.
To early ethologists, the major driving force in behavior was instinct,behaviors that are inherited and unchangeable. Moths move towards light because they inheritthe mechanism to so respond to light. Although dogs have more options availableto them, they bark at strangers for much the same reasons. The comparative behaviorists disagreed:learning and rewards are more important factors than instinct in animalbehavior. Geese are not born with theability to retrieve lost eggs when they roll out the nest, they learn to do so.If their behavior seems sometimes silly to humans because it fails to take newconditions into account, that is because the animal’s ability to learn islimited. There were too many examples of behaviors modified by experience forcomparative behaviorists to put their faith in instincts.
The arguments came to a peak in the 1950s and became known as the nature ornurture controversy.
Considerhow differently an ethologist and a comparative behaviorist would interpret thebegging behavior of a hatchling bird. The first time a hatchling bird isapproached by its parent, it begs for food. All baby birds of a particularspecies beg in exactly the same way. Obviously, said the ethologists, theyinherited the ability and the tendency to beg. Baby birds did not have to learnthe behavior, they were born with it—a clear example of innate, unchangingbehavior. Not so, countered the comparative behaviorists. Parent birds teachtheir young to beg by stuffing food in their open mouths. Later experimentsshowed that before hatching, birds make and respond to noises of their nestmates and adults. Is it not possible that young birds could learn to begprenatally?
It was hard for ethologists to accept that innate behaviors could be modified bylearning. It was equally difficult for comparative behaviorists to accept thatgenetic factors could dominate learning experiences. The controversy raged forover a decade. Eventually, however, the distinctions between the two fieldsnarrowed. The current view is that both natural endowments and environmentalfactors work together to shape behavior.
1.The word “ultimately” in the passage is closest in the meaningto
C.some of the time
D.in the end
2.According to paragraph 1, what do ethologists think is the most notablecharacteristic of animal behavior?
A.Animal responses in most situations are predictable and do notvary
B.In similar situations, different animal species often behave in similarways.
C.Even in ordinary situations, animal behavior can be unusuallycomplex.
D.Animal behavior may sometimes include stimulus/responsereactions.
3.According to paragraph 2, C. Lloyd Morgan agreed with which of the followingstatements about animal behavior?
A.Only those elements of animal behavior that could be observed and measuredshould be used to explain it.
B.Any study of animal behavior should include an explanation of emotions andmotivations.
C.Emotions and motivations can be measured indirectly using simple experimentalsituations.
D.Experimental situations are less than ideal if researchers want to develop acomprehensive explanation of animal behavior.
4.According to paragraph 2, comparative behaviorists were interested in findinganswers to all of the following questions EXCEPT
A.How has animal behavior changed over time?
B.How can emotions causing a specific behavior in one animal species help explainbehavior in other animal species?
C.To what degree can animal behavior be changed?
D.How does the nervous system regulate animal behavior?
5.Paragraph 3 suggests that comparative behaviorists’ conclusions concerninganimal behavior were based
A.on the observation that rewards do not affect inherited animalbehavior
B.on the application of stress to modify animal behavior
C.most often on the results of laboratory experiments
D.more on stimulus/response reactions than on simple rewards
6.The word “retrieve” in the passage is closest in meaningto
7.According to paragraph 4, why did comparative behaviorists believe that theirview of instinct in animal behavior was correct?
A.They had observed that animals can respond to the same stimulus in differentways.
B.They had demonstrated that animals could use learned behaviors in newconditions.
C.They had acquired sufficient evidence that instincts vary from one animal toanother.
D.They had shown that the behavior of many different animals had been changed bylearning.
8.The word “Obviously” in the passage is closest in meaningto
9.The word “countered” in the passage is closest in meaningto
10.In paragraph 5, why does the author discuss the begging behavior of a hatchlingbird?
A.To support the view that instinct explains animal behavior better than learningdoes
B.To demonstrate that ethologists are correct about the limited ability of animalsto learn
C.To contrast an ethologist’s explanation of a particular animal behavior withthat of a comparative behaviorist
D.To question whether the discussion about the roles of nature and nurture was avalid one
11.The word “current” in the passage is closest in meaning to
12.Look at the four squares  that indicate where the following sentence could beadded to the passage. Where would the sentence best fit?
Thisview is supported by the behavior of insects as well asanimals.
Wherewould the sentence best fit?
13.Directions: Select from the seven phrases below the phrases that correctlycharacterize ethologists and the phrases that correctly characterize comparativebehaviorists. Drag each phrase you select into the phrases will NOT be used.This question is worth 3 points.
A.Worked primarily in North America
B.Argued that animal behavior is passed on from one generation to another withoutchange over time
C.Maintained from the start that behaviors that are inherited could be influencedby learning
D.Believed that stimulus-response reactions serve to distinguish one animal fromanother just as their physical features do
E.Studied stimulus-response reactions and emphasized the importance of rewards forenforcing and changing behavior
F.Conducted more experiments with birds than with any otherspecies
G.Studied primarily how physical characteristics often determinebehavior.