Comparative psychology

Comparative psychology is a branch of study with roots in both biology and ethology (the study of animal behavior). The field of comparative psychology is based on the comparison of animal and human behavior, typically through the study of nonhuman animals in both laboratory and natural settings. Much of the research in this field is focused on the areas of learning and communication, specifically in reference to the nature versus nurture debate: how much of animal behavior is innate or instinctual (based in biology), and how much is learned, either through environmental cues or communication with other animals.

Brief History

The origins of comparative psychology can be traced back to two scientists, Pierre Flourens and George John Romanes. Romanes was a student of Charles Darwin and published his text, Animal Intelligence, in 1882. However, Flourens had been the first to use the term in his text, Comparative Psychology (Psychologie Comparée), in 1864. Both comparative psychology and ethology grew as linked yet separate disciplines. Oskar Heinroth, a biologist in the late nineteenth century, is noted as the first scientist to use this field of comparative study in the context of his research into animal behavior. Comparative psychology continued to gain momentum through the twentieth century, as psychologists from various fields, including learning, behavior, and epigenetics, began applying the theories to their own work. One concern raised in early comparative psychology research was anthropomorphism—the application of human traits, behaviors, or characteristics to nonhumans. Historically, comparative psychology research was conducted in a laboratory, while ethological study was conducted in the field.

Scientists studying comparative psychology and ethology tended to agree that evolution formed the basis of behavior but disagreed on one key point—whether the behavior is biological or psychological, commonly known as the nature versus nurture debate. The biological basis argues that behavior is inherited and evolves through genes. The psychological basis posits that behavior patterns change based on environment, not genetics.

While comparative psychology continued to grow as a discipline in the twenty-first century, ethology faltered. Most criticisms were based on the nature versus nurture argument—that behavior is not only biologically based. Ethology is housed under the umbrella of evolutionary psychology, which primarily studies human behavior, while comparative psychology is often studied in conjunction with behavioral neuroscience, which marries the studies of biology with psychology, genetics, and development.

Overview

Studies in comparative psychology continue in laboratories, in the field, and at zoos and aquariums. In a survey conducted in 2014 among comparative psychologists working in a variety of fields, including academic institutions, zoos and aquariums, and independent laboratories, research priorities identified included animal welfare, conservation, cognition (the process of acquiring knowledge), and neural-behavior interactions, among others. Although animal welfare and wildlife conservation have not traditionally been part of the field of comparative psychology, a better understanding of behavior will assist conservationists in protecting these species in the wild, as well as providing the best, most natural care and habitats in zoos and aquariums.

Scientists estimate that approximately 8.7 million different species of animals occupy the earth, and the specific topics of research within comparative psychology are similarly diverse. One common area of research is imitation because it is a type of social learning, not instinct—directly addressing nature versus nurture. Marine mammals are frequently researched in this context, particularly bottlenose dolphins, although birds and African elephants have also been studied. Extensive research has demonstrated that bottlenose dolphins have the ability to imitate sounds. In 2014, one group of researchers studying beluga whales demonstrated that the whales could imitate not only calls from other whales, but also sounds generated by computers or made by the experimenter. The whales, like bottlenose dolphins, were not able to exactly imitate sounds in human speech (neither beluga whales nor bottlenose dolphins possess vocal cords), but they were able to mimic rhythm and intonation (the way human voices rise and fall while speaking). The fact that these marine mammals can imitate sounds indicates that different vocalizations are used for social communication, such as to contact, identify, or form a bond with specific mammals in the group.

When referencing animal communication in this context, communication cannot be a one-way expression, but instead a transfer of information in which an expression by one animal causes a behavioral change in another. Researchers have found that some nonhuman primates, such as great apes, have similar brain structures to humans known as mirror neurons, which fire when an animal observes an action of another animal but experiences it as if it were occurring in its own brain. Primate brains have many significant differences as well, though, which seem to prohibit human speech. In one famous experiment in the 1960s, scientists Allen and Beatrix Gardner attempted to teach a female chimp American Sign Language (ASL). Although the chimp learned to use basic expressions, she never fully mastered ASL, and never spontaneously communicated with them using it. Further studies in nonhuman primates continue to reveal the complex mental capacity of some species, including the use of tools, self-awareness, adaptive behaviors, and complex social structures.

Researchers continue to argue that animals must be able to learn from their environments for a multitude of reasons, including finding food, evading predators, finding and defending a territory, finding mates, and identifying their young. Others disagree, finding that in some cases, learning actually comes at a cost when compared to automatic, hardwired behaviors. These researchers argue that when an environment is predictable, automatic responses help to guarantee survival. One related 2016 study demonstrated that people more quickly identify photos of snakes, and associate the image with fear, than with pictures of weapons—even though, in modern cultures, weapons are much more of a threat to survival. Monkeys responded in a similar manner to pictures of snakes as compared to images of other animals. This was true even of monkeys that had been raised in a controlled environment and had never seen a snake. These studies indicate that this type of quick identification is not a learned behavior, but is evolved.

Another form of communication—gazing into the distance following a cue given by another animal or a human also gazing into space—is important because it provides information related to survival, such as the presence of food or predators. Primates, goats, tortoises, and wolves, among others, engage in this behavior—and because it occurs only in certain contexts, it indicates that it is a learned rather than fully instinctual behavior.

Beginning in the late 2010s, comparative psychology research incorporated a more diverse range of species to create a comprehensive body of knowledge concerning species evolution and to identify neural correlates of animal behavior across species. Neurobiologists and comparative psychologists increasingly collaborate to conduct research with a multi-faceted approach. This knowledge can be applied to developing treatments for mental health conditions, preventing or slowing neurocognitive decline, and conserving the earth's biodiversity.

The field of comparative psychology, like the animals studied, continues to evolve. Research continues to focus on the competing influences of nature versus nurture and genetics versus cognition in human and animal behavior. Scientists aim to use the knowledge gained from comparative psychology studies to deepen their understanding of evolutionary processes across species and the intricacies of development.

Bibliography

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