Different Types of Learning

Different Types of Learning

It seems therefore that we need to “tune” the laws of learning on a case-by-case basis to accommodate the fact that a given species learns some relationships easily, others only with difficulty, and still others not at all. This tuning builds some flexibility into the laws of learning; but it allows us to retain the idea that there are general laws, appli-cable (with the appropriate tuning) to all species and to all situations. Other evidence suggests, though, that we must go further than this, because some types of learning follow their own specialized rules and depend on specialized capacities found in that species and few others. On this basis, we need to do more than adjust the laws of learn-ing. We may also need some entirely new laws—laws that are specific to the species that does the learning and to what’s being learned (Gallistel, 1990; Roper, 1983).

As one example, consider the Clark’s nutcracker, a bird that makes its home in the American Southwest (Figure 7.33). In the summer, this bird buries thousands of pine nuts in various hiding places over an area of several square miles. Then, throughout the winter and early spring, the nutcracker flies back again and again to dig up its thou-sands of caches. The bird doesn’t mark its cache sites in any special way. Instead, it relies on memory to find its stash—a remarkable feat that few of us could duplicate.

The Clark’s nutcracker has various anatomical features that support its food-hoarding activities—for example, there’s a special pouch under its tongue that it fills with pine nuts when flying to find a hiding place. The bird’s extraordinary ability to learn a huge number of geographical locations, and then to remember these locations for the next few months, is probably a similar evolutionary adaptation. Like the tongue pouch, this learning ability is a specialty of this species: Related birds like jays and crows don’t store food in this way; and, when tested, they have a correspondingly poorer spa-tial memory (D. Olson, 1991; Shettleworth, 1983, 1984, 1990).

Many phenomena of animal learning—in birds, fish, and mammals—reveal similar specializations. In each case, the organism has some extraordinary ability not shared even by closely related species. In each case, the ability has obvious survival value and seems quite narrow. The Clark’s nutcracker, for example, has no special skill in remem-bering pictures or shapes; instead, its remarkable memory comes into play only in the appropriate setting—when hiding and then relocating buried pine nuts. Similarly, many birds show remarkable talent in learning the particular songs used by their species. This skill, however, can be used for no other purpose: A zebra finch easily mas-ters the notes of the zebra finch’s song but is utterly inept at learning any other (non-musical) sequence of similar length and complexity. Truly, then, these are specialized learning abilities—only one or a few species have them, and they apply only to a partic-ular task crucial for their members’ survival (Gallistel, 1990; Marler, 1970).

But what about humans? We’ve emphasized that a great deal of human behavior—just like the behavior of every animal species—is governed by principles of habituation as well as classical and operant conditioning. But, even so, some of our behavior is the product of distinctly human forms of learning. One exam-ple involves the processes through which humans learn language. These processes seem controlled by innate mechanisms that guide the learning and make it possible for us to achieve remarkable linguistic competence by the time we’re 3 years old. Humans also have remarkable inferen-tial abilities that allow us to gain broad sets of new beliefs, based on events we’ve observed or information we’ve received from others; and these new beliefs can pro-foundly affect our behavior.