Midterm Examination - March 9, 2000

ANSWER KEY

1. Briefly identify ten of the following: (2 points each)

  1. Variance – a measure of how variable a set of scores on a test/trait are; a statistical measure of variability in a trait. (or equations)
  2. factor analysis – a statistical procedure for reducing a large set of scores into a smaller subset of factors; analyzes the correlations among many measures to discover dimensions or factors.
  3. rGxGy – genetic correlation between x and y; the correlation between genetic factors for x with genetic factors for y; a measure of the extent to which the same genes influence x and y.
  4. bipolar disorder – formerly called manic-depression; axis I disorder with fluctuations between mania and depression/ extreme mood swings.
  5. Alfred Binet – Developed the first successful standardized test of intelligence. Its purpose was to predict how kids would do in school.
  6. parasympathetic nervous system – Involves cholinergic processes which maintain homeostasis, usually in non-emergency situations; digestive and vegetative functions.
  7. heritability – VG /VP ; r2GP The relative importance of (proportion of variance explained by) genetic factors in phenotypic variance.
  8. trait – A stable, enduring characteristic
  9. selective placement – Matching characteristics of biological and adoptive parents when placing a child into an adoptive home.
  10. DSM-IV – Diagnostic and statistical manual of mental disorders; a manual used for classification of individuals with mental disorder.
  11. Flynn effect – Increase in mean IQ scores over the last 30 years in developed countries.
  12. equal environments assumption – the degree of environmental similarity is equivalent for MZ and DZ twin pairs.

2. Suppose a researcher, Dr. V. Olin, is interested in understanding individual differences in musical ability. List the four basic steps she must take in developing a measuring instrument for this trait. (8 points)

  1. Operational definition
  2. Unchanging measuring
  3. Compare individuals to instrument
  4. Compares scores to each other

3. Briefly define the two psychometric properties (reliability and validity) that Dr. V. Olin must establish for her new measuring instrument, and describe one way that she might establish each. (10 points)

Reliability – consistent scores; repeatability. Can be tested with test/retest, split-half, alternate forms

Validity – does the instrument measure what you think it is measuring. Construct validity. Compare to other measures.

4. Suppose that Dr. V. Olin's new measure is administered to a large sample of twins reared together, and a heritability of .40 is obtained. Which of the following statements, if any, is true? (Answer T or F for each statement; 10 points):

_F__ 20% of a person's musical ability is inherited from one's mother, and another 20% is inherited from one's father.

_F__ Music lessons (environment) can enhance a person's musical ability by about 60%, and the rest is genetic.

_F__ About 40% of accomplished musicians inherit their ability.

_F__ About 60% of the variance in musical ability is explained by genetic differences between individuals.

_F__ About 40% of the variance in musical ability is explained by experiences and other environmental factors that differ among individuals.

5. Suppose we compared the SAT scores of 1000 males and 1000 females and found that the verbal scores of students from wealthy families were higher on average than those from poor families. Is this evidence of test bias? Explain. (5 points)

No. It may simply be that true verbal ability differs between SES groups. A mean difference does NOT necessarily imply test bias.

6. Briefly list and describe some of the major features of Schizoypical Personality Disorder (SPD). What is the difference between a classification approach and a dimensional (or individual differences) approach to classifying persons with SPD? (10 points)

Ideas of reference, social anxiety, odd beliefs/ magical thinking, unusual perceptions, eccentric/odd, no close friends, odd speech, constricted affect, suspicious/paranoid.

Classification approach – meet or do not meet criteria. All or none.

Dimensional approach – people fall on a continuum; individual differences for trait.

7. Briefly describe two biological risk factors and their relationship to antisocial behavior. (6 points)

Birth complications and maternal rejection

Partial credit for: prefrontal cortex dysfunction and environmental stressors (or something similar).

8. How good are intelligence tests as predictors of human behavior? Describe at least three specific things that individual intelligence test scores do predict, as covered in the lecture and readings. (6 points)

See article by Neisser et al. (in the reader)

9. Suppose that musical ability correlates .60 between MZ co-twins raised apart. Also, the correlation between musical ability for MZ twins raised together is .75. (a) Calculate heritability, shared and non-shared environmentality for musical ability using these data. (b) Say in words what these results mean. (c) What reservations do you have about your estimates?

  1. h2 = .60, e2 s = .15, e2 ns = .25
  2. Sixty percent of the variance in musical ability can be explained by heritability. Fifteen percent of variance in musical ability can be attributed to shared environment factors etc.
  3. Assumption of selective placement and additive genes

Answer one of the following two questions (15 points):

10a. Discuss the evidence for both environmental and genetic causes of individual differences in general intelligence test scores. Be sure to distinguish between environmental factors both shared and not shared by family members, as well as possible developmental changes in all three types of influences.

-OR-

10b. Describe the Big Five theory of human personality, and discuss some of the variables which may explain individual differences on these traits. Include discussion of research on two physiological and two demographic variables that are related to Big Five personality characteristics.

(See Book)

---All components of question 10 must be addressed in order to receive full credit.