To someone with little or no knowledge of theories of human development it sometimes seems presumptuous for scientists to say that they can offer blanket explanations of human behavior, accounting for everyone in the world. This is not so difficult to accept if the theories are limited to explanations of purely physiological development because it is much easier to see physical commonalties. Behind the resistance to explanations of behavior, however, there is the firm belief that the individual "I"--the essence of the single, unique person who is an individual I--cannot possibly be reduced to formulas or charts, schedules of development, or schemes in which cherished personal traits are categorized like auto parts on a shelf. The irony is, of course, that this very resistance to classification is the result of one of the most important developmental processes. Most people go through enough trouble in actualizing the self that it is probably a sign of healthy development if a person does resist the idea that any schematic notion of development can account for him/her.
In looking at the various theories of development it is sometimes necessary to set aside one's first reaction to them. What makes innate sense for one individual may merely be a reflection of his/her own experience or learning. Thus Abraham Maslow's humanist perspective on development strikes the reader as immediately convincing because his hierarchy of needs makes common sense, fits ordinary perceptions of how life progresses, and generally "seems to be grounded in human experience" (Papalia, Olds and Feldman 443). One can easily imagine the states in which certain needs are not met (even if one has not experienced them personally) and the idea that "only when people have met basic needs can they strive to meet higher needs" seems both logical and a good explanation of the problems that face disadvantaged people in our society (443). It is also an optimistic t...