Physiology and Psychology
PHYSIOLOGY AND PSYCHOLOGY: A PRELIMINARY CONSIDERATION OF THEIR RELATIONSHIP*
N. H. Pronko
At the very outset, the student is urged to attempt an operational exercise which we believe will throw into bold relief the fundamental characteristics of psychological facts.
Let us take two different kinds of things to work with—a muscle-nerve preparation and a child. The first, a frog's leg muscle and attached nerve, is a typical laboratory assignment for the student of physiology. This portion of the frog (the rest of the frog may be discarded) can be rigged up and experimented with in such ways as to yield precise, useful knowledge about the functioning of muscles.
A weight can be hung on the leg and an electric current sent into the muscle over the nerve. In this way, the relationships between stimulus and response may be worked out. What are are some of these findings? First, we note that in physiology we can legitimately and profitably study parts of organisms systems or even organs, such as a beating heart.
The term "tissue excitation" appropriately applies to such an occurrence. Further, the responses we observe in physiology are automatic, constant, organized and permanent. Given the same conditions, the leg muscle will always respond in the same way. It cannot do otherswise. Because the leg muscle is constructed in a certain way and because is contractile tissue, it must contract in the way it does when it is properly stimulated.
Now, let us take a child. Say, "Good morning" to a newborn child and there is no response, nor will there be one for many months. One fine day, however, after many, many months of “stimulation” the child will respond with, “Good morning” when he is greeted.
Here we see the first big difference between the kinds of facts studied in physiology and those belonging to psychology. First of all, we must have a whole organism in psychology. Certainly, no lung, vocal cords, and head severed from an organism have ever been taught to say, "Good morning." And now we have come to the crucial difference.
Teaching comes in in psychology—not in physiology. As soon as a leg muscle has been developed, it will give a reflex response from the first contact. It does not have to be taught, but children will have to be taught to say, "Good morning."
How important the specific details of the child's history are can be strikingly shown if we transplant our child at birth into a family in France. Lo and behold, the child now responds with "Bon jour" and not "Good morning." It is apparent that whether the child responds at all, or the way it responds, is conditioned by many circumstances of a social sort. Not so with a muscle-nerve preparation.
The latter operates in the same fixed fashion whether the frog is raised in America, France, or the Soviet Union. Thus, a history of organisms with their stimulus objects is of prime importance in psychological study—not in physiology. Let the reader examine his own actions and test the validity of the distinction we have made here.
But the list of differences is not yet exhausted. Notice that a child may be angry and remain silent when his parent greets him upon waking. Again, leg muscles can't inhibit their response the way organisms do. When we find inhibitions prominently displayed in the activities of animals, let us agree to place them in a different class of activities from non inhibitable coughs, sneezes, and burps. The latter may be handed over to physiology.
Were we to study the child cited in the above examples over a period of time, we might observe that his response varies. Once, he says "Good morning"; then perhaps only "Morning," or "Howdy." Leg muscles can be counted upon not to change the patterning of their action. They will not run around in circles or zigzags. In other words, our study of a person's "good mornings" must encompass more territory if we are to understand the extra-tissue conditions to which they are sensitive.
A further difference shows up when we note that a child can delay his response until, let us say, after the other person has spoken. Not so with leg muscles. As soon as the muscle is stimulated it responds. People commonly delay their actions. When children frequently reply "Just a minute" to parental requests, illustrate the delayability not found in other phenomena.
Comparison of our two data brings out still another difference between them. Assume that the child in our example has had a teacher whom he did greet with "Good morning." The teacher moved away, and the child did not see her until 4 years later. On the occasion of their meeting after this interval, the child did not say "Good morning." His action had been modified; he had "forgotten" his teacher. Leg muscles do not "forget" stimuli with which they have been in contact 4, 10, or even more years previously.
People like people and things which they previously disliked, and vice versa. In other words, their action shows modifiability. This is another way in which they differ from tissues organs, and systems studied in physiology. The ubiquitous child of our illustrations can also do some-thing else that leg muscles in the laboratory cannot do. Although morning he can only concentrate on practicing the words "Good Morning," in time he can incorporate other actions with the verbal response.
For example, while he runs along, he can simultaneously take a lollipop out of his mouth and say his greeting person he meets while in motion and while holding the lollipop momentarily before his face. Humans perform highly integrated activity while driving, looking, and conversing, during machine operation, or while eating or dancing. Leg muscles do not act in this way.
A final important difference: If leg muscles are struck with a cardboard, hammer, reflex hammer, vulgar poster, ax, or any sharp-edged object, they react indiscriminately to these various objects. But organisms, during their historical contacts with the same objects, build up very specific actions toward them.
They come to chop with an ax, to pound nails with a hammer, to be shocked at vulgar posters, to use cardboard to make a sign, and to employ a reflex hammer for testing reflexes. In other words, humans are more discriminating than leg muscles, or, for that matter, sneezing or coughing reflexes. To put it still another way, humans come to perform very specific reactions to each of these things, whereas leg muscles react in the same way to any of them.
In summary, then, psychological events will show these characteristics. They will always require an organism rather than a discrete organ or system of organs. The latter, however, can be studied in physiology. Furthermore, psychological data can be counted upon to involve a history or series of contacts between the organism and the things or people to which it responds. Thus, if a person speaks Finnish, we may be certain that during his life span he was in contact with Finnish-speaking people. Conversely, if we know that a child has grown up with Finns, we may be sure that he has built up the specific verbal reactions to things that other Finns show, and that he can be counted upon to perform them.
Finally, psychological action can be distinguished from physiological in that the former will show modifiability, delayability, variability, inhibition, integration, and high degrees of discrimination. Not every behavioral act will show all six of these features. Then, there will be borderline cases, as there always are, but the authors venture to assert that the greater bulk of human activities of a behavioral sort can be distinguished on this basis from the non-behavioral or physiological sort.
The student should be told that a distinction between physiological and psychological data has not been attempted until recent times, and that some investigators ignore such differences. We are of the opinion that if such distinctions can be made and if they are valid, they can be tremendously helpful in delimiting a specific set of data. And, if our data are homogeneous, our principles ought necessarily to be more clean-cut and useful.
The whole purpose of this section has been suggestive. The student is urged to take such instances as coughing, belching, stomach gurgles, and swallowing, and compare them with his learning, remembering, reading, writing, running, voting, or creative activity. Operationally apply the test of the characteristics suggested above, and let the chips fall where they may. We are convinced that these criteria are practical in acquainting us with the essential features of behavioral facts.