Defining Abnormality
Because of the difficulty in distinguishing normal from abnormal behavior, psycholo-
gists have struggled to devise a precise, scientific definition of “abnormal behavior.”
For instance, consider the following definitions, each of which has advantages and
disadvantages:
•  Abnormality as deviation from the average. To employ this statistically based
approach, we simply observe what behaviors are rare or occur infrequently
in a specific society or culture and label those deviations from the norm
“ abnormal.”
  The difficulty with this definition is that some statistically rare behaviors
clearly do not lend themselves to classification as abnormal. If most people pre-
fer to have cornflakes for breakfast but you prefer raisin bran, this deviation
hardly makes your behavior abnormal. Similarly, such a concept of abnormality
would unreasonably label a person who has an unusually high IQ as abnormal,
simply because a high IQ is statistically rare. In short, a definition of abnormality
that rests on deviation from the average is insufficient.
•  Abnormality as deviation from the ideal. An alternative approach considers abnor-
mality in relation to the standard toward which most people are striving—the
ideal. This sort of definition considers behavior abnormal if it deviates enough
from some kind of ideal or cultural standard. However, society has few stan-
dards on which people universally agree. (For example, we would be hard-
pressed to find agreement on whether the New Testament, the Koran, the
Talmud, or the Book of Mormon provides the most reasonable standards.)