Statistical infrequency does not tell us the difference between desirable behaviour that is not statistically infrequent and the undesirable behaviour which is statistically infrequent.
An IQ of 140 would fall outside the 'normal' band, but we would not say that someone with a high IQ is abnormal or mentally ill.
Some behaviours that are experienced by most people e.g. anxiety, are seen as abnormal depending on the severity.
There are individual differences to consider when using the statistical infrequencydefinition.
Statistical infrequencydefinition is objective when compared to others as it used statistical data(quantitative) which is thought to be reliable.
It looks at the whole picture, taking all the population into account so can give a useful insight into the whole picture of a particular characteristic.
There is a degree of inflexibility with the statistical infrequencydefinition.
Infrequentbehaviour is not always negative.
In some cases finding infrequent behaviour is useful.
If a child is screened for dyslexia, they can receive help quicker.