Response biases

Think about these questions… „I like hurting people” „I tend to want others to admire me” „Sometimes, I am lazy.”

Response biases Can we trust the test score? Biases related to tested person Affect the test result Threats to reliability Especially self-report methods

Four patterns of responding Honest responding Irrelevant responding e.g. answering randomly Defensiveness – conscious denial Malingering – conscious fabrication

Response biases Social desirability bias (faking good) Faking bad Acquiescence (or yea saying) Opposition (or nay saying) Positional set (extremity and mid-point response) Random responding

Faking Faking – deliberate systematic distortion of the responses because the respondent wishes to create a particular impression. An emphasis on socially desirable characteristics Denial of negative behaviors

Faking good and bad Faking good – endorsing items that characterize personal honesty and virtue, good adjustment and mental health Reporting lack of weakness Faking bad – overendorse symptoms (clinical), a desire to appear poorly adjusted, perhaps mentally ill.

Acquiescence vs. Opposition Answering always YES or NO

Positional set Answering according to the position of the anwer, e.g. Likert scale:

Random responding Honest error – placing answers incorrectly Lack of understanding Willful behavior Lack of motivation

Reasons of biases in personality tests Delibarate faking Idealized presentation of oneself as opposed to a more realistic presentation Innacurate presentation because of lack of insight

Dealing with biases Incorporating measures of response bias in the test Compare results of a test with a measure of bias Determine how sensitive a scale is to faking

Detection of biases One group – one instruction. We look for items with low endorsment, e.g. „I am extremely honest in all my dealings”. One group – two instructions, e.g. „fake good”, „answer as a chronic alcoholic” Two groups – two instruction – one group with disorder and second normal that fakes. How the items differ, e.g. „I hear voices”

Other methods Construct specific items: have high predictive validity but low face validity Have high face validity but no predictive validity

Discourage faking Warning that distortion can be detected and punishment will follow Forced-choice items that are equated on social desirability, e.g. are you more reliable or agreeable? The use of subtle vs obvious items Use control scales

Example - MMPI Minnesota Multiphasic Personality Inventory Identify personality structure and psychopatology 567 questions Includes few so called validity scales – whether a diagnosis is valid

Validity scales in MMPI Cannot Say Scale (?): the number of items on the assessment that were left unanswered. Reasons: suspiciousness, lack of understanding, depression, fear of loss of privacy etc.)

The Lie scale Delibarate efforts to lie on the tests Detects whether individuals are making themselves seem more well adjusted than they actually are. Individuals that wish to present themselves in a more positive light

The Lie scale Facts common that most people are willing to admit: Denial of agression Prejudices Poor self-control Examples: „Sometimes I don’t say truth” „Sometimes I procrastinate my work”

Infrequency Scale To present oneself in a bad light. Items that endorsed very rarely on normal population – less than 10% Items ask about hostility, poor physicall health, feelings of isolation, atypical attitudes towards authority. „I have diarrhea once a month ore more often” „Sometimes ghosts attack me”

Infrequency Scale High score may be due to: Random answering Conscious tendency to present in bad light Malingering Crying for help Deviant behavior, not conventional

Defensiveness Scale Tendency to fake on the test in order to make themselves look better. Lie Scale and the Defensiveness Scale seem similar, Defensiveness Scale focuses on lies due to "defensiveness in admitting problems" and is done extremely subtly; whereas the lie scale detects simple lies meant to cast a better light on oneself.

Defensiveness Scale People may present themselves in a positive light unconsciously „Very rarerly I argue with my family.” (No)

Other problems with biases Test anxiety – unpleasant emotions related to test taking. Test situation is seen as threatning. Testwiseness – test sophistication, person’s ability to use the characteristics and format of a test (or test situation) to obtain a higher score