The Significance of Experimental Psychology

Though James did not use the term “experimental” in his own day, a significant part of his work is devoted to considering how the modification of physical circumstances could produce different cognitive outcomes—a radical breakthrough in psychological thought when The Principles of Psychology was published in the 1890s. What this means in modern-day psychological science is the manipulation of the independent variable and observation of the corresponding changes in the dependent variables. James writes,

The principal fields of experimentation so far have been... the connection of conscious states with their physical conditions, including the whole of brain-physiology, and the recent minutely cultivated physiology of the sense-organs, together with what is technically known as “psycho-physics,” or the laws of correlation between sensations and the outward stimuli by which they are aroused...

This identification of the relationship between environmental stimuli with both the sense and cognitive responses to them was an incredibly important discovery in psychology. Some scholars have postulated that James’s experimental approach inspired the conception of “classical conditioning,” whereby repeated, external stimuli would eventually engender an instinctive, reflexive response. This was most famously demonstrated in the experiments of Ivan Pavlov.

The Importance of Introspective Observation

In The Principles of Psychology, James defines “introspective observation” as “the looking into our own minds and reporting what we there discover.” His precept was based on the belief that all people have an inward recognition of their own thought processes and that careful observation of them would allow them to reconcile with their mental state and passions. Individuals may be mistaken from time to time about what kinds of inward cognitive states they actually possess; they might not fully understand the nature of their own thoughts or inner reflections. However, James argues that, through a process of internal self-correcting, a person would be able to come to a "consensus" about what he or she feels and thinks. This consensus would be the most effective tool that a psychologist could use to create a generalized understanding of a person’s "stream of thought"—which is itself indispensable to understanding conscious life.

The Nature of the Self

In chapter 10 of The Principles of Psychology, James puts forward his theory of multiple selves. He argues that an individual can have many “selves,” each exerting varying degrees of influence over his or her external behaviors at different times. However, these selves, which often correlate to different aspects of a person’s personality (passions, sense of morality, etc.), often conflict with one another; it is therefore the responsibility of the conscious person to decide which one may predominate. This choice will be reflected in external behavior and the ways in which a person chooses to behave in daily life. The particular “self” that a person chooses to direct his or her external behavior and disposition, thereafter, will determine his or her self-recognition of success. James says, “Our self-feeling in this world depends entirely on what we back ourselves to be and do.” James’ conceptualization of multiple selves, therefore, touches on a very humanistic explanation of individual choice and free will.