Psychologist Bertram R. Forer (1914-2000) found that people tend to accept vague and general personality descriptions as uniquely applicable to themselves without realizing that the same description could be applied to many people. Consider the following as if it were given to you as an evaluation of your personality.
You have a need for other people to like and admire you, and yet you tend to be critical of yourself. While you have some personality weaknesses you are generally able to compensate for them. You have considerable unused capacity that you have not turned to your advantage. Disciplined and self-controlled on the outside, you tend to be worrisome and insecure on the inside. At times you have serious doubts as to whether you have made the right decision or done the right thing. You prefer a certain amount of change and variety and become dissatisfied when hemmed in by restrictions and limitations. You also pride yourself as an independent thinker; and do not accept others' statements without satisfactory proof. But you have found it unwise to be too frank in revealing yourself to others. At times you are extroverted, affable, and sociable, while at other times you are introverted, wary, and reserved. Some of your aspirations tend to be rather unrealistic.Forer gave a personality test to his students, ignored their answers, and gave each student the above evaluation (taken from a newsstand astrology column). He asked them to evaluate the evaluation from 0 to 5, with "5" meaning the recipient felt the evaluation was an "excellent" assessment and "4" meaning the assessment was "good." The class average evaluation was 4.26. That was in 1948. The test has been repeated hundreds of time with psychology students and the average is still around 4.2 out of 5, or 84% accurate.
In short, Forer convinced people he could successfully read their character. His accuracy amazed his subjects, though his personality analysis was taken from a newsstand astrology column and was presented to people without regard to their sun sign. The Forer effect seems to explain, in part at least, why so many people think that pseudosciences "work". Astrology, astrotherapy, biorhythms, cartomancy, chiromancy, the enneagram, fortune telling, graphology, rumpology, etc., seem to work because they seem to provide accurate personality analyses. Scientific studies of these pseudosciences demonstrate that they are not valid personality assessment tools, yet each has many satisfied customers who are convinced they are accurate.
The most common explanations given to account for the Forer effect are in terms of hope, wishful thinking, vanity, and the tendency to try to make sense out of experience. Forer's own explanation was in terms of human gullibility. People tend to accept claims about themselves in proportion to their desire that the claims be true rather than in proportion to the empirical accuracy of the claims as measured by some non-subjective standard. We tend to accept questionable, even false statements about ourselves, if we deem them positive or flattering enough. We will often give very liberal interpretations to vague or inconsistent claims about ourselves in order to make sense out of the claims. Subjects who seek counseling from psychics, mediums, fortune tellers, mind readers, graphologists, etc., will often ignore false or questionable claims and, in many cases, by their own words or actions, will provide most of the information they erroneously attribute to a pseudoscientific counselor. Many such subjects often feel their counselors have provided them with profound and personal information. Such subjective validation, however, is of little scientific value.
Psychologist Barry Beyerstein believes that "hope and uncertainty evoke powerful psychological processes that keep all occult and pseudoscientific character readers in business." We are constantly trying "to make sense out of the barrage of disconnected information we face daily" and "we become so good at filling in to make a reasonable scenario out of disjointed input that we sometimes make sense out of nonsense." We will often fill in the blanks and provide a coherent picture of what we hear and see, even though a careful examination of the evidence would reveal that the data is vague, confusing, obscure, inconsistent or unintelligible. Psychic mediums, for example, will often ask so many disconnected and ambiguous questions in rapid succession that they give the impression of having access to personal knowledge about their subjects. In fact, the psychic need not have any insights into the subject's personal life for the subject will willingly and unknowingly provide all the associations and validations needed. Psychics are aided in this process by using cold reading techniques.
David Marks and Richard Kammann argue:
....once a belief or expectation is found, especially one that resolves uncomfortable uncertainty, it biases the observer to notice new information that confirms the belief, and to discount evidence to the contrary. This self-perpetuating mechanism consolidates the original error and builds up an overconfidence in which the arguments of opponents are seen as too fragmentary to undo the adopted belief.Having a pseudoscientific counselor go over a character assessment with a client is wrought with snares that can easily lead the most well intentioned of persons into error and delusion.
Barry Beyerstein suggests the following test to determine whether the apparent validity of the pseudosciences mentioned above might not be due to the Forer effect, confirmation bias, or other psychological factors. (Note: the proposed test also uses subjective or personal validation and is not intended to test the accuracy of any personality assessment tool, but rather is intended to counteract the tendency to self-deception about such matters.)
…a proper test would first have readings done for a large number of clients and then remove the names from the profiles (coding them so they could later be matched to their rightful owners). After all clients had read all of the anonymous personality sketches, each would be asked to pick the one that described him or her best. If the reader has actually included enough uniquely pertinent material, members of the group, on average, should be able to exceed chance in choosing their own from the pile.
The Forer effect, however, only partially explains why so many people accept as accurate occult and pseudoscientific character assessment procedures. Cold reading, communal reinforcement, and selective thinking also underlie these delusions. Also, it should be admitted that while many of the assessment claims in a pseudoscientific reading are vague and general, some are specific. Some of those that are specific actually apply to large numbers of people and some, by chance, will be accurate descriptions of a select few. A certain number of specific assessment claims should be expected by chance.
There have been numerous studies done on the Forer effect. Dickson and Kelly (1985) have examined many of these studies and concluded that overall there is significant support for the general claim that Forer profiles are generally perceived to be accurate by subjects in the studies (D. H. Dickson and I. W. Kelly, "The 'Barnum Effect' in Personality Assessment: A Review of the Literature," Psychological Reports, 57, 367-382.). Furthermore, there is an increased acceptance of the profile if it is labeled "for you." Favorable assessments are "more readily accepted as accurate descriptions of subjects' personalities than unfavorable" ones. But unfavorable claims are "more readily accepted when delivered by people with high perceived status than low perceived status." It has also been found that subjects can generally distinguish between statements that are accurate (but would be so for large numbers of people) and those that are unique (accurate for them but not applicable to most people). There is also some evidence that personality variables such as neuroticism, need for approval, and authoritarianism are positively related to belief in Forer-like profiles. Unfortunately, most Forer studies have been done only on college students.