Quetelet is considered to be the most influential social scientist. Aside from that, he is an accomplished astronomer, meteorologist and statistician. He has also introduced the concept of statistics. Being an experienced mathematician, he applied this concept in studying physical attributes and psychological characteristics (Neuroportraits).
Firstly, his major contribution to the study of psychology is placing the foundation that human actions and behavioral pattern, no matter how random may still fall into the known spectrum of data. He was able to study large numbers of subjects and quantify human traits, characteristics and behaviors. In a way, the scientific and analytical approach in measuring social behavior had led to the development of Psychology. He was able to apply his knowledge of statistics in interpreting social dynamics, most especially his study of psychological behaviors. He also established uniformity of a collected data under given specific time and place. He reasoned that uniformity is necessary for the validity of the study and more reliable findings. He was able to successfully link certain human attributes to different psychological activity. He was successful in introducing scientific approach in studying social science. His approach to this subject in an analytical manner made it easier for social scientists to deduct conclusion and generalize their observation in a measurable quantity. For example, he was able to link literacy and criminal activity. There was a general finding that those with lower literacy, especially those that cannot read nor write have a higher percentage of theft and other criminal acts. This study is part of his moral statistics. Moral statistics is part of the general science that classifies an individual’s action as moral or immoral.
Secondly, he was able to introduce the concept of “average man”. He made sure to propose the concept of Body Mass Index (BMI), or previously known as Quetelet Index. Though not directly to Psychology, further studies of Body Mass Index can trigger solid relation to social interaction. It can be a big factor in a person’s self-esteem and awareness (Healthaliciousness.com). Most of social behavior can be linked to the physical attribute of the individual. The concept of “average man” can also be associated with the predominant representation of the data population. He was able to discover that most human characteristic fall on the average. And that most seek to belong to the median part of the average population given a specified upper and lower limit. When these traits are collected and plotted on a chart, it forms a bell-like shape indicating higher frequency of occurrence of that trait near the median or average. The plotted data would show the bell shape pattern with tails on decreasing rate. However, deviation may be observed on the end tails of the bell, but on much lower frequency. This deviation means that variations from the "average" trait may happen, but in few instances only.
Quetelet had never planned for the development of Psychology nor stabling a new venture in social sciences. His penchant for measuring irregularities into uniformity of known patterns led to this particular advancement. He was able to devise a way for behavioral qualities to be studied clearly by transforming them to measurable records. The development of Psychology can greatly be derived from the transformative view of Quetelet to social science. Psychology has greatly relied on statistical studies about human behavior in order to explain the general situation of different psychological activity.
References
Neuroportraits.eu, 'Lambert Adolphe Jacques Quetelet | Portraits of European Neuroscientists'. N. p., 2014. Web. 7 May. 2014.
Healthaliciousness.com, 'Adolphe Quetelet Creates The Body Mass Index (BMI)'. N. p., 2014. Web. 7 May. 2014.