Many events and traits can be represented with a bell-shaped curve. The average events are most common, and they represent the high, middle of the curve. As traits or events become less common, the curve falls, demonstrating that extreme traits and extreme events occur less frequently than average traits or events.
Behaviors displayed my the most infrequent occurrences are considered abnormal and "statistically infrequent." These events are not necessarily bad, dangerous or harmful--for example, an extremely high IQ--but they are statistically improbable and abnormal. These are often called "statistically infrequent" events.
Statistical Infrequency is a term used to refer to abnormal events. Abnormal here refers to events that occur rarely, but the events themselves are not necessarily good or bad--for example, a very high IQ score and a run on 2's on a series of dice rolls are infrequent, but neither is necessarily bad.
Statistical Infrequency is not enough to rate an event or trait as positive or negative. Rare traits and events can be good or bad. Be aware that statistical infrequency or a notice of "statistical abnormality" does not imply a bad event or trait.
In psychology. the behaviors and attributes that most people have are considered normal. Outlying traits are those that are "statistically infrequent," and they are considered abnormal. This differentiation informs the criteria that describe mental disorders. Care must be taken to ensure that statistically rare events that are not harmful or may even be beneficial are not accidentally cataloged as pathological simply because they are abnormal.