The Science of Human Nature: A Psychology for Beginners

by William Henry Pyle

Law. The service of psychology to law can be very great, but owing to the necessary conservatism of the courts, it will be a long time before they will make much use of psychological knowledge. Perhaps the greatest service will be in determining the credibility of evidence. Psychology can now give the general principles in this matter. Witnesses go on the stand and swear to all sorts of things as to what they heard and saw and did, often months and even years previously. The expert clinical psychologist can tell the court the probability of such evidence being true. Experiments have shown that there is a large percentage of error in such evidence. The additional value that comes from the oath has been measured. The oath increases the liability of truth only a small percentage.

Experiments have also shown that one’s feeling of certainty is no guarantee of truth. Sometimes the point we feel surest about is the one farthest from the truth. In fact, feeling sure of a thing is no guarantee of truth.

In a particular case in court, the psychologist can determine the reliability of the evidence of a particular witness and enable the judge and the jury to put the proper value on such witness’s testimony. For example, a witness may swear to a certain point involving the estimation of time and distance. The psychologist can measure the witness’s accuracy in such estimates, often showing that what the witness claims to be able to do is an impossibility. A case may hinge on whether an interval of time was ten minutes or twelve minutes, or whether a distance was three hundred or four hundred feet. A witness may swear positively to one or both of these points. The psychologist can show the court the limitations of the witness in making such estimates.

Psychology can be of service in the examination of the criminal himself. Through association tests and in other ways, the guilt or innocence of the prisoner can often be determined, and his intellectual status can also be determined. The prisoner may be insane, or feeble-minded, or have some other peculiar mental disorder. Such matters fall within the realm of psychology. After a prisoner has been found guilty, the court should have the advice of the clinical psychologist in deciding what should be done with him.

It should be added that the court and not the attorneys should make use of the psychologist. Whenever a psychologist can be of service in a case in court, the judge should summon such assistance, just as he should if expert chemical, physical, physiological, or anatomical knowledge should be desired.

A knowledge of human nature can be of much service to society in the prevention of crime. This will come about from a better knowledge of the psychological principles of habit-formation and moral training, through a better knowledge of how to control human nature. A large percentage of all crime, perhaps as much as forty per cent, is committed by feeble-minded people. Now, if we can detect these people early, and give them the simple manual education which they are capable of receiving, we can keep them out of a life of crime.

Studies of criminals in reform schools show that the history of many cases is as follows: The person, being of low mentality, could not get on well at school and therefore came to dislike school, and consequently became a truant. Truancy led to crime. Crime sent the person to the court, and the court sent the person to the state reformatory.

The great duty of the state is the prevention of crime. Usually little can be done in the way of saving a mature criminal. We must save the children before they become criminals, save them by proper treatment. Society owes it to every child to do the right thing for him, the right thing, whether the child is an idiot or a genius. Merely from the standpoint of economy, it would be an immense saving to the state if it would prevent crime by the proper treatment of every child.

Business. The contribution of psychology in this field, so far, is in the psychology of advertising and salesmanship, both having to do chiefly with the selling of goods. Students of the psychology of advertising have, by experiment, determined many principles that govern people when reading newspapers and magazines, principles having to do with size and kind of type, arrangement and form, the wording of an advertisement, etc. The object of an advertisement is to get the reader interested in the article advertised. The first thing is to get him to read the advertisement. Here, various principles of attention are involved. The next thing is to have the matter of the advertisement of such a nature that it creates interest and remains in memory, so that when the reader buys an article of that type he buys the particular kind mentioned in the advertisement.

In salesmanship, many subtle psychological principles are involved. The problem of the salesman is to get the attention of the customer, and then to make him want to buy his goods. To do this with the greatest success demands a profound knowledge of human nature. Other things being equal, that man can most influence people who has the widest knowledge of the nature of people, and of the factors that affect this nature. The successful salesman must understand human feelings and emotions, especially sympathy; also the laws of attention and memory, and the power of suggestion. A mastery of the important principles requires years of study, and a successful application of them requires just as many years of practice.