Understanding Psychology (10th Ed)

461
Key Concepts
How can we most accurately 
assess personality?
What are the major types of 
personality measures?
M O D U L E 4 2
Assessing Personality: 
Determining What Makes 
Us Distinctive 
You have a need for other people to like and admire you. 
You have a tendency to be critical of yourself. 
You have a great deal of unused potential that you have not turned to your advantage. 
Although you have some personality weaknesses, you generally are able to compensate 
for them. 
Relating to members of the opposite sex has presented problems for you. 
Although you appear to be disciplined and self-controlled to others, you tend to be 
anxious and insecure inside. 
At times you have serious doubts about whether you have made the right decision or 
done the right thing. 
You prefer a certain amount of change and variety and become dissatisfi ed when 
hemmed in by restrictions and limitations. 
You do not accept others’ statements without satisfactory proof. 
You have found it unwise to be too frank in revealing yourself to others. 
If you think these statements provide a surprisingly accurate account of your per-
sonality, you are not alone: Most college students think that these descriptions are 
tailored just to them. In fact, the statements were designed intentionally to be so 
vague that they apply to just about anyone (Forer, 1949; Russo, 1981). 
The ease with which we can agree with such imprecise statements underscores 
the diffi culty in coming up with accurate and meaningful assessments of people’s 
personalities. Psychologists interested in assessing personality must be able to 
defi ne the most meaningful ways of discriminating between one person’s person-
ality and another’s. To do this, they use psychological tests, standard measures 
devised to assess behavior objectively. With the results of such tests, psychologists 
can help people better understand themselves and make decisions about their 
lives. Researchers interested in the causes and consequences of personality also 
employ psychological tests (Aiken, 2000; Kaplan & Saccuzzo, 2001; Hambleton, 
2006). 
Like the assessments that seek to measure intelligence, all psychological tests 
must have reliability and validity. Reliability refers to a test’s measurement consis-
tency. If a test is reliable, it yields the same result each time it is administered to a 
specifi c person or group. In contrast, unreliable tests give different results each time 
they are administered. 
For meaningful conclusions to be drawn, tests also must be valid. Tests have 
validity when they actually measure what they are designed to measure. If a test is 
constructed to measure sociability, for instance, we need to know that it actually 
measures sociability and not some other trait. 
Study Alert
The distinction between reli-
ability and validity is impor-
tant. For instance, a test 
that measures trustfulness 
is reliable if it yields the 
same results each time it is adminis-
tered, while it would be valid if it 
measures trustfulness accurately.