You must turn off your ad blocker to use Psych Web; however, we are taking pains to keep advertising minimal and unobtrusive (one ad at the top of each page) so interference to your reading should be minimal.

If you need instructions for turning off common ad-blocking programs, click here.

If you already know how to turn off your ad blocker, just hit the refresh icon or F5 after you do it, to see the page.

Psi man mascot

The Early 1800s

In the early 1800s, there was no distinct science of psychology. The word psychology was used to label a branch of philosophy concerned with human consciousness.

The term scientist itself did not come into general use until the 1840s. However, before there was a science of psych­ology, there were two influential ancestors of the field: phrenology and psycho­physics.

Phrenology is a now-discredited theory that bumps on the skull could predict a person's character or personality traits. The original idea for phrenology came from Francis Gall in 1796. He made a reasonable sounding assumption: brain areas should grow when exercised, like muscles.

Therefore (he reasoned) the shape of the skull should reflect the size or devel­opment of the underlying brain tissue, and a bump on the skull might indicate well-developed brain tissue below.

The phrase, "You ought to have your head examined" goes back to phrenologists. They literally examined people's heads in order to analyze their personalities.

The following illustration shows a phrenology chart. Areas on the skull are mapped and numbered. For example, if you had a bump in area 6, right above the ear, a phrenologist might say you were prone to destructiveness.

diagram of a head has various areas labeled
A phrenology chart shows which areas were thought to be associated with personality traits

Unfortunately for the phrenologists, their primary assumption was false. Bumps on the brain do not reflect the size or development of underlying brain areas.

Moreover, the assignment of personality traits to brain areas was entirely fanciful. For example, activity in the brain tissue over the ear is not related to destructiveness, according to modern brain scanning techniques.

What is phrenology, and what was wrong with it?

Phrenology may have been a false science, but some of its elements foreshadowed modern psychology. For example, phrenologists assumed different brain regions had distinct skills or functions. That idea has returned in today's neuroscience.

The phrenologists wanted a scientific, objective way to measure psychological qualities. That is still a goal of psychologists.

Phrenologists believed valuable information about a person could be gathered in a short amount of time, using an objective test. Testing is still used by many psychologists.

Finally, phrenologists were almost right in their primary hypothesis: that the brain was like a muscle that would grow when exercised. Neurons grow if they are used, extending their branching pattern and making new connections. However, this growth is not reflected in bumps on the skull.

What were some ways that phrenology foreshadowed later elements of psychology?

Despite the impressive array of "modern" elements, phrenology was a failure. Its primary hypothesis about bumps on the skull was false. The assignment of personality traits to particular areas of the brain (shown in the diagram) was inaccurate.

Phrenology clinics remained popular up through the 1890s and the early years of the 20th Century. They became an embarrass­ment to psychologists, who publicly dissociated themselves from the phrenology and denounced it as a fraud.

Classic Psychophysics

One reputable early ancestor of psychology is still taught in upper level psychology courses: psychophysics. We will discuss the modern version of it in Chapter 4, in the section on Psycho­physics.

The word psychophysics refers to the interaction of the mind (psyche) and the physical world (physics). Psycho­physicists were interested in exploring how energy from the physical world such as light and sound gave rise to mental experience such as perception of brightness and loudness.

What was the concern of psychophysics?

In the history of psychology, psycho­physics was important because it was rigorous and scientific, unlike much of early psychology. Psycho­physics experiments took place under carefully controlled laboratory conditions.

The quest to explore these issues led to formation of the first psychological laboratories. A book about psycho­physics by Gustav Fechner, published in 1869, is widely considered the beginning of experimental psychology.

What positive influence did psychophysics have upon psychology?

Using instruments available in the mid-1800s, psychophysicists tried to answer questions like these:

1. What is the smallest unit of energy a person can detect? (For example, what is the dimmest light or sound one can detect?)

2. What is the smallest change of energy a person can detect? (For example, what is the smallest change in brightness of a light or the smallest alteration in the loudness of a sound perceivable by a person?)

What sorts of questions did psychophysicists ask?

Psychophysics relied heavily upon graphs and equations. Their shiny brass instruments (and equations) were impressive and intimidating to beginning students. William James wrote in 1876:

It is more than doubtful whether Fechner's "psychophysic law" of any great psycho­logical importance... but because these things are very difficult and very "scientific," people...will distrust all teachers who have not swallowed and assimilated them. (James, Burkhardt, Bowers, and Skrupskelis, 1978, p. 6).

In other words, psychophysics was very impressive, partly because it was difficult to understand. However, to James, psycho­physics did not seem to have much practical relevance to psychology.

Nevertheless, psychophysics endured. It tackled a basic philosophical problem: how stimulation coming the outside world was translated into human experience.

What was William James's opinion of psychophysics, in 1876?

With the development of the Theory of Signal Detection in the 1960s, psycho­physics achieved a new level of sophisti­cation and relevance. At the same time it became more relevant to psychological issues.

Out of psychophysics came "d-prime," a statistic for estimating the sensitivity of an observer in noisy situations. Statistical tools developed from the 1940s to 1970s can analyze any decision made under conditions of uncertainty. That covers a lot of territory.

Examples of signal detection include deciding which alternative is correct on a multiple choice test, judging whether a face looks happy, recognizing a known pattern (such as a missile) in a noisy background, deciding whether a dark spot in medical imaging data is a tumor, discriminating between different sources of music such as different headphones, detecting changes in pain due to acupuncture (if any) and much, much more.

The details of psychophysics are complex, just as they were in James's time. However, Signal Detection Theory is extremely useful in science. In Chapter 4 we will return to the topic for a closer look.

Wundt's "New Psychology"

Wilhelm Wundt (1832-1920) was the first professional to call himself a psychologist. In 1879 he founded one of the first psychological laboratories in Leipzig, Germany.

Wundt believed the "only certain reality is immediate experience" (Blumenthal, 1975). If psychology were to be a science, then psychologists would have to collect data about experience.

To collect data about experience, Wundt used procedures similar to those in psycho­physicists. He arranged controlled laboratory settings to expose people to various types of stimuli, and he recorded what they reported.

He did not restrict himself to simple stimuli. He also studied illusions, religious feelings, and other complex psychological events.

Wundt took behavioral measure­ments as well, including how quickly people responded to a stimulus (reaction time). Wundt believed these experiments would lead eventually to a consensus or agreement among scientists about the nature of experience.

old picture of Wundt
Wilhelm Wundt

Wundt's approach was not unreasonable. It resembled the way most natural sciences developed in the 1800s.

Sciences like botany and zoology began with careful observation. As data accumulated, scholars attempted to arrive at consensual validation (agreement among different observers). For example, biologists began by collecting specimens, carefully describing them, and attempting to classify them.

How did Wundt intend to build a science of psychology?

Wundt believed the same approach should work in psychology. Careful scientific observers could look inside to see the mind in action.

According to Wundt, observers of scientific data should be able to agree on what they saw, and that included the data of experience. The technique of looking inside to gather data is called introspection .

The problem with Wundt's program is that people are different. Not everybody has the same experience. Even under standardized conditions, people might see or exper­ience different things when looking inside.

This was not obvious to Wundt. He assumed people would report the same experiences of controlled stimuli, under controlled laboratory conditions.

Wundt assumed that if people did not make the same observations of their experience, under identical conditions, they must be doing something wrong. To some Americans visiting his lab, Wundt seemed like a bully, pushing people to have the same inner observations as himself.

As time went on, introspectionism, the method of looking inside to gather data, proved to be unreliable. If there was variation in what people saw (and there always was) it was unclear how to resolve differences of opinion to arrive at the desired consensus.

For example, a major controversy erupted over the issue of imageless thought. Could a thought exist without an image?

Some scientists looked inside and said yes: some thoughts existed without any pictures or images in the mind. Others said no, there was always an image, although it might be faint.

What was the problem with Wundt's research program? How does the issue of "imageless thought" provide an example?

When discussing intro­spection, I some­times asked students for their own opinions about the existence of imageless thought. Using a show of hands, students indicated whether they could generate an thought without any accompanying image or not.

Every time, there was a difference of opinion. Some said they could do it, many said they could not. Maybe people are biologically different in this regard. Maybe people have different criteria for what constitutes an inner image.

Given such disagreements, there is no way to arrive at a consensus. That ultimately led to the downfall of introspection as the primary source of data in psychology.

James and Functionalism

Another approach to psychology, formulated in the 1890s, was the functionalism of William James. James is often described as the father of American psychology. He regarded the mind as a process, a function of the organism.

Image of James
William James

By the 1890s scientists were acquainted with Darwin's idea that humans evolved from simpler animals. James argued that consciousness must have evolved because it was useful for something.

In other words, it had a function. If we wanted to understand the origins and purpose of a psychological phenomenon, James suggested, we should ask what it accomplished for the organism.

James gave his opinions in a book, Principles of Psychology, published in 1890. It came in two large volumes and was a bit long for many students.

He followed it up with Psychology: The Briefer Course in 1892, in one small volume. Also famous is James's 1902 publication: The Varieties of Religious Experience.

What was the main idea of James's functionalism?

James is remembered as a great psychologist because he wrote well and had good judgment about what ideas were interesting or important. Psychologists living a century after James found his insights "exciting" because they seemed so modern (Kimble, 1990).

Why do many present-day psychologists respect William James?

A reviewer of Principles of Psychology on called it "fresh as a morning flower." However, James himself did little research, and his examples came mostly from everyday life, not from laboratory experiments.


Blumenthal, A. L. (1975). A reappraisal of Wilhelm Wundt. American Psychologist, 30, 1081-1087.

James, W., Burkhardt, F., Bowers, F., & Skrupskelis, I.K. (1876/1978) Essays in philosophy. Cambridge, MA: Harvard University Press.

Kimble, G. A. (1990). A search for principles in principles of psychology. Psychological Science, 1, 151-155.

Write to Dr. Dewey at

Don't see what you need? Psych Web has over 1,000 pages, so it may be elsewhere on the site. Do a site-specific Google search using the box below.