Line	Critics maintain that the fiction of Herman Melville
	(1819–1891) has limitations, such as its lack
	of inventive plots after Moby-Dick (1851) and its
	occasionally inscrutable style. A more serious, yet
(5)	problematic, charge is that Melville is a deficient
	writer because he is not a practitioner of the “art of
	fiction,” as critics have conceived of this art since the
	late nineteenth-century essays and novels of Henry
	James. Indeed, most twentieth-century commentators
(10)	regard Melville not as a novelist but as a writer of
	romance, since they believe that Melville’s fiction
	lacks the continuity that James viewed as essential
	to a novel: the continuity between what characters
	feel or think and what they do, and the continuity
(15)	between characters’ fates and their pasts or original
	social classes. Critics argue that only Pierre (1852),
	because of its subject and its characters, is close to
	being a novel in the Jamesian sense.
	However, although Melville is not a Jamesian
(20)	novelist, he is not therefore a deficient writer. A more
	reasonable position is that Melville is a different
	kind of writer, who held, and should be judged
	by, presuppositions about fiction that are quite
	different from James’s. It is true that Melville wrote
(25)	“romances”; however, these are not the escapist
	fictions this word often implies, but fictions that
	range freely among very unusual or intense human
	experiences. Melville portrayed such experiences
	because he believed these best enabled him to
(30)	explore moral questions, an exploration he assumed
	was the ultimate purpose of fiction. He was content
	to sacrifice continuity or even credibility as long
	as he could establish a significant moral situation.
	Thus Melville’s romances do not give the reader
(35)	a full understanding of the complete feelings and
	thoughts that motivate actions and events that shape
	fate. Rather, the romances leave unexplained the
	sequence of events and either simplify or obscure
	motives. Again, such simplifications and obscurities
(40)	exist in order to give prominence to the depiction of
	sharply delineated moral values, values derived from
	a character’s purely personal sense of honor, rather
	than, as in a Jamesian novel, from the conventions of
	society.

    Social learning in animals is said to occur when direct or indirect social interaction facilitates the acquisition of a novel behavior. It usually takes the form of an experienced animal (the demonstrator) performing a behavior such that the naive animal (the observer) subsequently expresses the same behavior sooner, or more completely, than it would have otherwise. One example of social learning is the acquisition of preferences for novel foods.

    Some experiments have suggested that among mammals, social learning facilitates the identification of beneficial food items, but that among birds, social learning helps animals avoid toxic substances. For example, one study showed that when red-wing blackbirds observed others consuming a colored food or a food in a distinctly marked container and then becoming ill, they subsequently avoided food associated with that color or container. Another experiment showed that house sparrows consumed less red food after they observed others eating red food that was treated so as to be noxious. Studies on nonavian species have not produced similar results, leading researchers to speculate that avian social learning may be fundamentally different from that of mammals.

    But Sherwin's recent experiments with domestic hens do not support the notion that avian social learning necessarily facilitates aversion to novel foods that are noxious or toxic. Even when demonstrator hens reacted with obvious disgust to a specific food, via vigorous head shaking and bill wiping, there was no evidence that observers subsequently avoided eating that food. Sherwin's research team speculated that ecological or social constraints during the evolution of this species might have resulted in there being little benefit from the social learning of unpalatability, for instance, selective pressures for this mode of learning would be reduced if the birds rarely encountered noxious or toxic food or rarely interacted after eating such food, or if the consequences of ingestion were minimal. In a related experiment, the same researchers showed that if observer hens watched demonstrator hens react favorably to food of a particular color, then observer hens ate more food of that color than they ate of food of other colors. These results confirmed that avian species can develop preferences for palatable food through social learning.

    By the sixteenth century, the Incas of South America ruled an empire that extended along the Pacific coast and Andean highlands from what is now Ecuador to central Chile. While most of the Incas were self-sufficient agriculturists, the inhabitants of the highland basins above 9,000 feet were constrained by the kinds of crops they could cultivate. Whereas 95 percent of the principal Andean food crops can be cultivated below 3,000 feet, only 20 percent reproduce readily above 9,000 feet. Given this unequal resource distribution, highland Incas needed access to the products of lower, warmer climatic zones in order to enlarge the variety and quantity of their foodstuffs. In most of the preindustrial world, the problem of different resource distribution was resolved by long-distance trade networks over which the end consumer exercised little control. Although the peoples of the Andean highlands participated in such networks, they relied primarily on the maintenance of autonomous production forces in as many ecological zones as possible. The commodities produced in these zones were extracted, processed, and transported entirely by members of a single group.

    This strategy of direct access to a maximum number of ecological zones by a single group is called vertical economy. Even today, one can see Andean communities maintaining use rights simultaneously to pasturelands above 12,000 feet, to potato fields in basins over 9,000 feet, and to plots of warm-land crops in regions below 6,000 feet. This strategy has two principal variations. The first is "compressed verticality," in which a single village resides in a location that permits easy access to closely located ecological zones. Different crop zones or pasturelands are located within a few days walk of the parent community. Community members may reside temporarily in one of the lower zones to manage the extraction of products unavailable in the homeland. In the second variation, called the "vertical archipelago," the village exploits resources in widely dispersed locations, constituting a series of independent production "islands." In certain pre-Columbian Inca societies, groups were sent from the home territory to establish permanent satellite communities or colonies in distant tropical forests or coastal locations. There the colonists grew crops and extracted products for their wn use and for transshipment back to their high-altitude compatriots. In contrast to the compressed verticality system, in this system, ommodities rather than people circulated through the archipelago.