IX. Individual Differences
We readily perceive the physical differences among men - one never sees two people who are exactly alike. The height and weight vary, the color of skin and eyes, the shape of the body and features, and so on. Physicians can tell us that we differ internally as well: we have the same basic parts, but the precise shape of the bones, muscles, organs, and vessels are subtly different among individuals.
There are certain ranges that can be anticipated, but the existence of individuals who are far outside the normal ranges shows that there are no fixed patterns for the human body, though there are a number of general tendencies.
For example, the weight of most people falls within a fairly small range. It is also not unusual to see those who are outside that range, considered to be emaciated or obese, but who are regularly encountered. And then, there are those who are so far outside the normal range as to be considered freakish, and whose deviation from the average range is startling and a bit unnerving to witness.
(EN: It occurs to me that there is some danger in presuming that "average" is a desirable trait to have. People shun others whose physical characteristics are too unusual. And for all their pretensions of scientific objectivity, even physicians show prejudice against people who are unusual and may diagnose as unhealthy someone who is not at all dysfunctional, but merely outside of the anticipated range.)
The same is true of the differences in the mental capacities and psychological characteristics of individuals. There is a central tendency or average, some who deviate to a small degree, and still others who deviate to a significant degree. Further, it is more likely that we are more different and over a greater range mentally than physically because mental characteristics are not anchored to physical causes in most instances.
Mental Differences
Just as we differ physically, so also we differ mentally, and various tests of mental capacities follow in the same basic pattern of distribution, demonstrating that many people cluster toward a central or normal range, but that there are many who fall outside of this range and a few who tend to the extremes.
Experiments demonstrate that mental characteristics have at least some degree of independence, similar to physical ones. There is a natural correlation, for example, between height and weight (the taller, the heavier) but no correlation between the shape of the eyes and shape of the fingernails. Similarly a person's reasoning skills may be correlated to his attention span, but his ability to calculate sums does not correlate to his ability to memorize sentences.
However, it does seem that mental abilities are specialized and attune themselves to certain activities. Pianists will tend to have scores within a similar range in terms of some mental characteristics, which are different to the abilities that are more developed in painters or hunters. It remains arguable whether a person is drawn to an activity because they have certain "natural" abilities or those abilities are developed as a consequence of engagement in an activity. This is likely a circular argument.
There are likewise sharp-minded individuals who have greater ability in multiple mental skills as well as feeble-minded individuals who have little ability in anything. It often draws curiosity when an individual who is in most regards shows an unnaturally high level of ability in only one specific area such as playing a flute or memorizing lists of numbers. This is commonly seen among those diagnosed as autistic or regarded as idiot-savants.
As such, the scientist may note mental differences but be attentive to their lack of correlation. A person may in a general sense be assessed as normal, brilliant, or idiotic - but it is likely each person has different levels of different mental abilities. The most typical arrangement is to be normal in most regards and gifted or debilitated in only a few.
Problems of Observation
The mental capacities of human beings cannot be observed directly, but can be observed in their ability to perform tasks that are subject to observation. Just as a person's strength may be assessed by gauging their ability to lift objects of various weights, so can their memory be assessed by gauging their ability to remember a list of words or a sequence of numbers.
This first requires devising an activity in which a mental ability is engaged. Different mental functions - perceiving, remembering, reasoning, etc. - are engaged by specific tasks that can be measured, either by a binary assessment (success or failure) or by degrees (how fast, how many, how long, etc.)
A specific problem for psychological testing is the influence and practice and learning. It is unlikely that, during a brief test of physical strength, that a subject will grow stronger as a result of the test activities, though he may become tired and perform worse if the duration of the test is prolonged. It is however quite common that during a brief test of a psychological capacity such as memory that the subject will develop their abilities even after a few iterations.
So in addition to measuring the mental capacity of subjects, the rate at which they improve must also be carefully monitored to consider not only their average performance, but the degree to which their performance improves during the course of the experiment.
Another specific problem for psychological testing is the influence of observation. In the natural environment of the home, school, or place of work a person tends to pay little attention to routine tasks that they perform. In the setting of a laboratory, where they are aware that they are being monitored and measured, individuals are prone to placing greater importance on tasks that would otherwise merit little attention or effort.
These two factors also tend to work against one another: whereas training causes an individual to improve their performance over time, observation causes them to perform well in early trials and them to diminished over time as they become accustomed to being observed.
For this reason, the various tests of mental capacity cannot be a perfect representation of normal behavior in an everyday situation, but likely remain adequate for the purpose of investigation and comparative studies among subjects in similar situations.
Example Tests of Mental Abilities
The manner in which a test of mental abilities is conducted is of great importance. The findings of a badly conceived or conducted test are worse than useless in that they can be misleading.
The design of the test must be contrived to isolate, inasmuch as possible, a single mental ability to be assessed. If an activity engages multiple abilities, the results represent the confluence of multiple abilities in a manner that cannot be conveniently separated.
Each test must be conducted in a manner that provides reliable results. For example, it matters whether or not the purpose of the test is explained to the subject, whether individuals are tested in groups or in isolation, etc. There are no specific qualities that make all tests support every test, as the design of the experiment must include those procedures most supportive of the specific phenomenon it means to assess.
Consistency, however, is important regardless of the kind of test that is being performed. If some subjects are told about the capacity being assessed whereas others are not, the results will be inconsistent. Any inconsistencies should be noted, and ideally they should be intentional to contrast the influence of specific environmental factors.
That said, Pyle means to provide descriptions of a number of different tests of mental abilities, with specific information of their purpose and methodology, as examples of effective test design and conduct.
Logical Memory
The first test Pyle describes was conducted to determine a pupil's ability to remember and reproduce information, such as is necessary to academic performance.
The method of the test involved teachers reading, slowly and distinctly, a story that students would then recollect in their own words, preserving as many details as possible. The students would be read a story and then write the story over the course of ten minutes, and were not to begin writing until after the story had been told.
(EN: Examples of three stories are given here, one for grade school, another for junior high, and another for high school students. The stories are similar in complexity and are cued to be read in a similar manner.)
Test results were analyzed by calculating the percentage of story details that were given in the students' retelling. The results were graphed to demonstrate the range and central tendency of responses. Separate graphs were prepared for the students of different ages, genders, races, and the like.
(EN: The findings of the test are not disclosed in detail, as the purpose of the present chapter is to present the design and methodology of testing.)
Other Tests
(EN: A number of other tests are described: rote memory, substitution, free association, synonyms and antonyms, acronyms, sentence completion, and reading comprehension. All follow the same basic pattern above - describing the objective, test method, and analysis. It becomes rather excessive after the first two examples, and the reader might be better served by more detailed exposition and fewer examples.)
Practical Application of Assessment
In psychology, it is possible to conduct experiments in pursuit of pure or applied science.
Pure science investigates phenomena for the simple purpose of collecting information about them - which may not have any practical application at all. It serves no purpose unless and until a purpose is found for the information that was collected - likely by someone else, and likely years after the research was conducted. And it may never find a practical application.
Applied science begins with a purpose and then designs experiments to support that purpose. It is still a process of discovery, but it is focused on discovering specific things that have practical application. The information discovered can be put to immediate use in the achievement of a real-world goal. It is possible that the findings of applied science serve no purpose, but because it was conducted with a purpose in mind, it is more likely to have a practical application.
Education
The author's personal interest in psychology is to improve the educational process. It can readily be observed that students learn differently - some students learn quickly and become frustrated by the repetition done for the sake of others, other students learn slowly and are frustrated if there are too few repetitions. The general approach to educating all students by the same methods produces a great many failures.
Ideally, school work would be adapted to the student - but to do so requires knowing the unique capacities of the individual student: which learning methods work best, how many repetitions are needed, etc. And this is where psychological testing has a practical application.
There is already in schooling some separation of students by grade: this system structures education so that each grade can build upon the knowledge gained in previous grades - but because students differ in their learning abilities, there are wide variances in the abilities of students in the same grade. While all were exposed to the same material in previous grades, some learned it better than others.
The further along in school, the more detrimental it becomes to be lacking the information that was assumed to have been gained in previous grades. This explains the reason that the drop-out rate among high school students is much higher than that among elementary school students. It also suggests that the problem cannot be "fixed" in later years - as the lessons taught in the second grade are not repeated in the tenth, but lack of this information prevents success in the later grade. The student has no recourse nor support to regain what was lost eight years ago, as well as the detriment of the loss of eight years of learning due to the lack of foundational skills and knowledge.
Pyle posits that this can be remedied by separating students not only by age, but also by learning ability. The very best system of education assigns a child to an individual mentor who can adapt his teaching to the student's learning abilities. Failing that, students of similar abilities may be grouped, and taught by the methods that are most effective to their learning styles.
It's implied that the method of teaching is presently selected according to what works best for the teacher, rather than what works best for the students. So what is most necessary is a teacher who is attuned to the students' mental abilities, and who can tailor their lessons accordingly.
The Workplace
(EN: Pyle gives a rather more superficial explanation of how psychological differences can be used in selecting and training employees. Whether it's because it is of secondary interest to him, or because he feels the same principles apply. However, in practical terms there is simply more demand: there is a financial interest in selecting and training workers, and more opportunity and funding in occupational training than classroom education. So it likely merits greater attention.)
Psychological assessment is also of value in the workplace, especially in the author's time when industrialization had led to the specialization of labor. To be effective at a job required a specific set of abilities and significant training to be able to execute the work.
The first area in which assessment is valuable is in selecting candidates for employment: one can analyze the current workforce to determine which mental capacities are pronounced in the best workers, and then use that assessment as a register to assess applicants. The most qualified applications are the ones who have the mental characteristics that match those of the most productive workers.
Another area in which assessment is valuable is in training employees. Just as with students in school, adults in the workplace have different learning styles and can most quickly and effectively be trained to their work if the instructional methodology matches their personal learning profile.
He then switches back to schools, which provide a general education to all students. This is necessary because in western culture individuals are expected to follow their own course in life - they are not trained from birth to a specific occupation, but are given broad education to enable them to pursue a profession of their choice.
While this is likely a good course for the earliest years of education, students should be able to specialize their studies in subjects at which they excel - while they should not be trained for a specific occupation, they can be trained for a specific category of careers so that they develop their unique abilities to the greatest extent. That is, they should excel in a few areas in which they show greatest potential rather than being educated to be mediocre in areas that are not their strength.
Abnormal Individuals
A small number of individuals are of such high or low mental skills that they cannot be successful in ordinary school work. As soon as such pupils can be identified with relative certainty, they should be removed from regular classes and put into special classes that are tailored to their unique abilities.
It would be a mistake to attempt to get these students to do the regular schoolwork - because they simply cannot. It is a waste of time and a great deal of frustration for teacher and student alike to attempt to compel them to learn in a manner and at a rate that is simply not in their nature by virtue of their mental abilities.
If students cannot be individually educated, at the very least they should be grouped into classrooms of similar ability so that the teaching method can be adapted to their needs.
Testing can be helpful in this regard, and Pyle mentions a specific battery of tests (Binet-Simon) that seems to be effective in assessing students to identify those that are subnormal or supernormal in their learning abilities.
He concedes that "a child's fate should not depends solely upon any number of any kind of tests" and a practical assessment is advisable to ensure that the testing produced accurate results.