social norms and statistical
TRANSCRIPT
Definitions of AbnormalityDefinitions of Abnormality
Defining a person or behaviour as Defining a person or behaviour as ‘abnormal’ implies something undesirable ‘abnormal’ implies something undesirable and requiring changeand requiring change
Therefore, we must be careful how we use Therefore, we must be careful how we use the termthe term
Psychologists need methods for Psychologists need methods for distinguishing ‘normal’ from ‘abnormal’distinguishing ‘normal’ from ‘abnormal’
Definitions of AbnormalityDefinitions of Abnormality
Our definition of abnormality must be Our definition of abnormality must be objective:objective:– It must not depend on anyone’s opinion or It must not depend on anyone’s opinion or
point of viewpoint of view– It should produce the same results whoever It should produce the same results whoever
applies itapplies it
It must not be under- or over-inclusiveIt must not be under- or over-inclusive– It must not label as ‘abnormal’ or ‘normal’ It must not label as ‘abnormal’ or ‘normal’
behaviours or traits that aren’tbehaviours or traits that aren’t
Statistical InfrequencyStatistical Infrequency
Under this definition, a person’s trait, Under this definition, a person’s trait, thinking or behaviour is classified as thinking or behaviour is classified as abnormal if it is rare or statistically abnormal if it is rare or statistically unusual.unusual.
With this definition it is necessary to be With this definition it is necessary to be clear about how rare a trait or behaviour clear about how rare a trait or behaviour needs to be before we class it as needs to be before we class it as abnormalabnormal
Statistical InfrequencyStatistical Infrequencyfr
eque
ncy
70 100 130
IQ Scores
Average IQ in the population is 100pts.
The further from 100 you look, the fewer
people you find
Statistical InfrequencyStatistical Infrequencyfr
eque
ncy
70 100 130
IQ Scores
A very small subset of the population (<2.2%) have an IQ below 70pts. Such people are statistically rare. We regard them as having abnormally low IQs
Deviation from Social NormsDeviation from Social Norms
Under this definition, a person’s thinking or Under this definition, a person’s thinking or behaviour is classified as abnormal if it behaviour is classified as abnormal if it violates the (unwritten) rules about what is violates the (unwritten) rules about what is expected or acceptable behaviour in a expected or acceptable behaviour in a particular social group.particular social group.
Their behaviour may:Their behaviour may:– Be incomprehensible to othersBe incomprehensible to others– Make others feel threatened or uncomfortableMake others feel threatened or uncomfortable
Deviation from Social NormsDeviation from Social Norms
With this definition, it is necessary to With this definition, it is necessary to consider:consider:– The degree to which a norm is violated, the The degree to which a norm is violated, the
importance of that norm and the value importance of that norm and the value attached by the social group to different sorts attached by the social group to different sorts of violation.of violation.
– E.g. is the violation rude, eccentric, abnormal E.g. is the violation rude, eccentric, abnormal or criminal?or criminal?