The concept describes a symmetrical, bell-shaped distribution of data, where the majority of values cluster around the mean. In psychological contexts, this distribution frequently appears when analyzing traits, abilities, or behaviors within a population. For instance, if researchers measure the intelligence quotients (IQs) of a large, representative sample of individuals, the resulting scores tend to approximate this curve, with most scores concentrated near the average IQ and fewer scores appearing at the extremes.
The significance lies in its utility as a benchmark for comparison and evaluation. By understanding that certain characteristics are typically distributed in this manner, researchers can identify and analyze deviations from the norm. This allows for the identification of individuals who may require specialized interventions or resources, or who exhibit exceptional talents. Historically, its application has been crucial in the development of standardized psychological assessments and diagnostic criteria. Furthermore, it informs decisions about resource allocation and program development within educational and clinical settings.