Developmental psychology studies the way human beings develop from the time they are born until the time they die. Developmental and lifespan psychology has become a discipline within psychology, and has contributed with theories from many different psychologists. During the lifespan the person develops a personality, and behaves in a distinct way. This behavior becomes the person’s personality and rarely changes (Allen, 2005). Developmental psychology and personality theories explain human behavior, but there is still much debate over which theories are correct or valid. Psychology will advance, and it is conceivable that someday there will be not only valid explanations about development and behavior, but also the scientific evidence to back up those theories. Robert M. Yerkes is an American psychologist whose background is very interesting. Yerkes is most famous for the development of the intelligence test which was used during WWI. Yerkes was not always a psychologist however; he actually grew up a farmer and performed that job for many years. Yerkes received some financial support from family members and became a doctor. The transition from a farmer to a doctor is a very interesting part of the Yerkes contribution to psychology. The interesting element is because Yerkes family were mostly farmers and that is the only job Yerkes knew into his adulthood, and then suddenly he made a dramatic change, going to college, graduating from Harvard University, and becoming not only a psychologist, but one of the most remembered pioneers of psychology. Yerkes had a very deep interest in comparative psychology, a branch of psychology that deals with the behaviors of animals, and compares that behavior to humans. There are many reasons Yerkes could have wanted to become a psychologist, one is that he likely would have wanted a better life than that of a farmer, and it is likely that he also had a lot of interest in human behavior. Yerkes was also very interested in the study of Eugenics, which is the scientific study to alter genetics to improve genetic characteristics in the species. This is something Yerkes likely had experience with as a farmer. It is commonly known that farmers have a tendency to make improvements to their stocks or products using biological techniques. For example some farmers have been known to use steroid type enhancements to make their animals and vegetables bigger. Personality theories suggest that Yerkes had an introverted personality type, with a classical “A” personality in highly competitiveness. This is supported by the competitive nature in intelligence testing and eugenics. Types A personalities are people who are highly competitive, and who have are at risk of coronary disease due to stress, and the constant need to be over achievers (Allen, 2005). Type “B” personalities are the type of people who actually are very mellow, not very competitive, and generally more relaxed then “A” types of personalities (Allen, 2005). There are of personalities which are a combination of both A and B. Introversion personality types are people who are more likely to be loners, and hermit types. These people have some social anxiety, or feel awkward around other people. Introversion can also be when a person is just self-absorbed, and just wants to study, or be alone. Extroversion is the opposite of introversion, as extroverts tend to want to be around people. Extroverts are likely to attend parties, work well in groups, and have good interpersonal skills (Allen, 2005). Environment plays a crucial role in the development of a person’s personality, and there is evidence to suggest that a person’s personality rarely changes. There are of course plenty of people who may have been introverted types during one part of their life, but extroverted in other parts of their lives. This may be in part because of social factors such as a violent crime. A person for example may be extroverted but suffer from a violent crime and become introverted. Genetic factors also play a role in the development of personality (Dilalla, 2004). People have been known to exhibit the same type of personalities as their parents, or older siblings. These genetic factors have been studied and do not just apply the personality types, but the physical health as well (Dilalla, 2004). For example many people have been known to inherit the same genetic illnesses as their parents. A man, who died of a heart attack at the age of 42, could also leave the son to suffer the same fate unless early detection of the disease along with preventative measures is taken. Tempers and other violent tendencies have also been studied in genetic psychology. These studies have started the debate of nature vs. nurture. While it is true that genetic predisposition is a crucial factor in a person’s personality, it is also true that environmental factors also play a role in a person’s development. There are also media, educational, and social factors which are important to consider in personality development (Barondes, 2011). People can be influenced by not only the behaviors of their immediate family members, but other people such as friends, and teachers. Social personality influences include, but may not be limited to the media, and friendships (Barondes, 2011). The media influences children every day. Many kids watch TV, and then start the process of demonstrating the behaviors and interest seen (Barondes, 2011). For example a child may watch a show about a cowboy who shoots it out with Indians, and decides he wants to be like the cowboy in the show. The children will likely then dress like a cowboy, and play with a similar toy gun. While the child knows that he is not the character in the show, and will eventually assume his original personality, the imitation will lead to subtle personality changes that can last a life time. Robert Yerkes was likely an introverted type, with an A type of personality, based on the competitive nature of his theories, such as intelligence testing, and eugenics. He was likely motivated to leave the career as a farmer for a more be fitting career as a psychologist. Motivated by his ambitious nature, Yerkes likely worked very hard in school, and became one of the most important psychologists in history. Yerkes also received financial and moral support from his family members, which played a crucial part in his success in college, and most notably Harvard University.
Personality Theories, Bern P. Allen, 2005
Behavior genetics principles, Elizabeth Dilalla, 2004
Making sense of people, Samuel Barondes, 2011