However, contemporary literature on the subject seems to establish the priciples of comparivie psychology as ones that focus on both proximate and ultimate causation (Dewsbury, 1984). The power, though, of the comparative approach lies in the ability that the scholar can evaluate target behaviors from really four different perspectives, called Tinbergen's four questions (Burkhardt, 2005).

How pervasive is the behavior across the individual species -- how common is it?

How does the behavior contribute to overall evolutionary success via natural selection (reproductive success)?

What mechanisms are involved in the behavior -- what physiological, environmental or behavioral components must occur?

How does maturation and development contribute to this behavior?

Numerous studies have been done regarding comparative psychology, some even so popular that they are studied by elementary students. However, a few seminal studies have dominated the field. Pavlov, for instance, used dogs to understand the issues of conditioning. Thorndike studied cats and rats to understand patterning, Skinner used pigeons to understand his theories of psychological modeling, and Harlow's studies of maternal deptivation in rhesus monkeys are all part of the vast array of data used to show that indeed there are cross-specieis behaviors that are indicative of homo sapiens. Most recently, studies using Afrian Gray Parrots and the Dolphin uncover even more similarities in behavioral issues (Papini, 2008).

With the advent of more cross-discipline programs in the universities, comparative psychology has undergone somewhat of a revision in its basic approach. Instead of focusing on animal behavior in order to explain human behavior, comparative psychologists are reversing the trend and using the basic principles discovered in human...

This approach has led to numerous advances in the theory of cognition, concept formation, memory, and unique problem solving; and is called animal cognition psychology (Brown, et.al., 2006).
3. Freud's study of consciousness differed significantly from the work carried out by Wundt and his students and from William James' study of consciousness. Describe the ways that Freud's work differed from the work of Wundt and James.

Sigmund Freud (1856-1939) founded the psychoanalytic school of psychiatry and is best regarding for his theories of the unconscious mind and the defense mechanism of repression. William James (1842-1910) was one of the pioneers of early psychological understandings of humans, but trained as a medical doctor. He was interested in the way humans perceived the religious experience, mysticism, and how the mind acted to learn new things.

One must first understand that Freud was not completely contemporaneous with Wundt and James, and therefore there is some scholarly overlap that occurred in the way the three men considered their subject matter, as well as their cultural experiences and the overall "theme" of the times in which they lived.

Freud tended to subdivide and categorize the mind into more quantitative levels of consciousness, but continued to emphasize the unconscious. This evoloved into his famous trio: the id, ego and superego as the building blocks for all human bahevior. It is this pre-counscious, or subconscious level that, for Freud, tended to establish the bulk of the individual's way of being, way of perceiving, and even way of learning (Kahn, 2002).

James, however, perceived himself as a philosopher, attempting to uncover the balances between reality and experience. It was the experience of religion, of esctascy, of pain,