statistical infrequency

• A norm is a standard rule that regulates behaviour in a social setting
• Norms are socially acceptable standards of behaviour
• Abnormality is defined as moving away from the norm
• Statistical deviation is when an individual has a less common characteristic than the majority of the population e.g being more depressed or more intelligent
• IQ is an example of a characteristic that can be reliably measured
• Psychologists use a normal distribution curve to display statistical infrequency
• The average IQ is 100
• Most people (68%) have an IQ range between 85-115. Only 2% have a score below 70
• individuals with IQs below 70 are likely to be diagnosed with intellectual disability disorder and are considered abnormal
• Statistical infrquency has real life application in the diagnosis of a disorder
• All assessments of patients with mental disorders have measurements of how severe their symptoms are compared to the statistical norm
• the Beck Depression Inventory (BDI) is an assessment tool based on statistical infrequency, where a score of +30 is indicative of severe depression
• A limitation of this definition is that it suggests only usual characteristics can be positive
• IQ scores of over 130 are just as unusual as those below 70 but would we consider this undesirable?