What often has to be developed when using direct observation as a form of measure?

According to Eysenck, people who have decreased reactivity the limbic system (the emotional circuits), reticular activating system, and cortex are more likely to be ______________

A) extraverts B) neurotic C) intorverts D) conscientious

Which criterion would designate as abnormal a person who never talks to other people?

a) dysfunctional b) statistical rarity c) subjective discomfort d) malnutrition