Psychology 7

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Psychology 7 Experimental Psychology
Measurement/ Evolutionary Psychology
Well, were lost. I knew from the start that it
was just plain idiotic to choose a leader based
simply on the size of his or her pith helmet.
Sorry, Cromwell.
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Exam 1
Tuesday
Bring a ParScore form
Different versions of the test, make sure you
write down the appropriate version on your
ParScore form.
50 multiple choice questions
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Intelligence
Operational definitions
Intelligence is related to the speed of mental
processing.
Intelligence is the ability to think creatively.
Intelligence is a variety of mental and physical
abilities.
Intelligence is a general factor.
Intelligence Quotient (IQ)
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Wechsler Adult Intelligence Scale
Verbal subtest
Comprehension
Why should we obey traffic laws and speed limits?
Information
What is entomology?
Arithmetic
Six men can finish a job in ten days. How many
men will be needed to finish the job in two and a
half days?
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Wechsler Adult Intelligence Scale
Performance subtest
Block design
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History of the Intelligence Test
Alfred Binet
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IQ Population Distribution
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10
of people with this score
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2
100
85
70
55
115
130
145
IQ
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Mentally Impaired
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Is the IQ test a reliable and valid measure of
intelligence?
Reliability
test-retest reliability if an individual is
tested at two different times will the scores be
the same?
Pearson product-moment correlation coefficient (
r )
Can range from -1.00 to 1.00
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• IQ at age 18 correlates r .89 with IQ at age
  12, and at r .77 with IQ at age 6
• IQ generally does not deviate more than about 5
  over an individuals lifetime

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Is the IQ test a reliable and valid measure of
intelligence?
Reliability
internal consistency reliability
Split-half reliability if you divide the items
of a test in half would both halves have the same
score.
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• Subscales of the WAIS test correlate fairly
  highly with one another from .50 to .81
• Charles Spearman proposed g as the general
  intelligence factor that is called upon for any
  intellectual task and thus explains high
  correlations between IQ test subscales
• Performance on any one subscale then a function
  of both g and skills specific to that scale

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Construct Validity

• Face Validity Measure appears to measure what
  it is intended to measure
• Criterion-oriented validity Measure relates to
  theoretically predicted criteria
• Predictive Validity
• Concurrent Validity
• Convergent Validity
• Discriminant Validity

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Is the IQ test a reliable and valid measure of
intelligence?
Validity
Intellectual Aptitude Test
convergent validity
Is it related in a predictable way to other
variables that are supposed to measure the same
thing?
IQ Test
Success in school
predictive validity
Is it related in a predictable way to future
behavior?
IQ Test
IQ tests correlate .50 and above with grades in
school
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Is the IQ test a reliable and valid measure of
intelligence?
Validity
concurrent validity
Does the measure correlate with current behavior?
Do different groups of people differ on the
measure in expected ways?
discriminant validity
Does the measure assess the intended construct
better than other constructs?
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Is the IQ test a reliable and valid measure of
intelligence?
Validity
face validity
Does it make sense? Is it measuring what its
supposed to be measuring?
Emotional Intelligence (EQ)
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Measurement Scales
Nominal Scales
a categorical variable no numerical or
quantitative properties.
Example In the 1989 Buss study, male or female
subject is a nominal scale.
Independent variables are often measured on
nominal scales
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Measurement Scales
Ordinal Scales
a rank order of the levels of a variable.
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• The intervals between numbers are not necessarily
  equal on an ordinal scale.
• E.g., list your 10 favorite songs 1-10.
• It may be that you like 1 and 2 about the same
  but like these much more than 3 if so, the
  distance between 1 and 2 is not the same as the
  distance between 2 and 3

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Measurement Scales
Interval Scales
the intervals between the numbers are equal in
size, and there is no absolute zero point.
IQ scores are measured on an interval scale since
the interval between, say, 85 and 100 is the same
magnitude as the interval between 100 and 115
(i.e., 1 standard deviation)
However, a score of 0 on an IQ test does not
indicate the complete absence of intelligence
there is no absolute zero point
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Measurement Scales
Ratio Scales
the intervals between the numbers are also equal
in size, but there is an absolute zero point.
Examples include measures such as length, weight,
and time
Unlike interval scales, can form ratios and
validly say that, for instance, one person is
twice as tall as another
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Theory
Hypotheses
Predictions
Data/Observations
Conclusions
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Evolutionary Psychology

• Metatheoretical position that the human brain
  contains a collection of specialized processing
  mechanisms designed by natural selection to
  address specific problems encountered by our
  ancestors over the course of human evolution
• Examples of Adaptive Problems
• Visual scene analysis Food choice
• Mate choice/attraction Predator avoidance
• Navigation Parenting

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Meta-Theory
EP Specialized mechanisms
Theory
Mating Parental Investment Theory
Hypotheses
Predictions
Measures/Results
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PARENTAL INVESTMENT THEORY

• Trivers (1972) predicted that the sex with the
  greater typical parental investment in offspring
  becomes a limiting resource for the reproductive
  success of the opposite sex
• Females of most species make larger typical
  parental investment than do males
• Batemans data with fruit flies

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Eagerness for Sex/Sexual Variety

• Coolidge Effect
• Clark and Hatfield Study

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Percent of subjects who agreed when approached by
an opposite-sex stranger
Go on a date tonight
Go to bed with me tonight
Women
Men
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Meta-Theory
EP Specialized mechanisms
Theory
Mating Parental Investment Theory
Hypotheses
Buss study hypotheses
Predictions
Measures/Results
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Sex differences in human mate preferences
evolutionary hypotheses tested in 37 cultures.
Hypothesis 1 Females should seek to mate with
males who have the ability and willingness to
provide resources . . . Such as food, shelter,
territory, and protection.
Hypothesis 2 Males should prefer attributes in
potential mates associated with reproductive
value or fertility, . . .
Prediction 2 Males, more than females, will
value relative youth and physical attractiveness
in potential mates because of their links with
fertility and reproductive value.
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Sex differences in human mate preferences
evolutionary hypotheses tested in 37 cultures.
Hypothesis 1 Females should seek to mate with
males who have the ability and willingness to
provide resources . . . Such as food, shelter,
territory, and protection.
Prediction 1 Females, more than males, should
value attributes in potential mates such as
ambition, industriousness, and earning capacity
that signal the possession or likely acquisition
of resources.
1.08
1.96
36 out of 37 countries
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Sex differences in human mate preferences
evolutionary hypotheses tested in 37 cultures.
Hypothesis 1 Females should seek to mate with
males who have the ability and willingness to
provide resources . . . Such as food, shelter,
territory, and protection.
Prediction 1 Females, more than males, should
value attributes in potential mates such as
ambition, industriousness, and earning capacity
that signal the possession or likely acquisition
of resources.
1.84
2.45
29 out of 37 countries
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Sex differences in human mate preferences
evolutionary hypotheses tested in 37 cultures.
Hypothesis 2 Males should prefer attributes in
potential mates associated with reproductive
value or fertility, . . .
Prediction 2 Males, more than females, will
value relative youth and physical attractiveness
in potential mates because of their links with
fertility and reproductive value.
-2.66
3.42
37 out of 37 countries
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Sex differences in human mate preferences
evolutionary hypotheses tested in 37 cultures.
Hypothesis 2 Males should prefer attributes in
potential mates associated with reproductive
value or fertility, . . .
Prediction 2 Males, more than females, will
value relative youth and physical attractiveness
in potential mates because of their links with
fertility and reproductive value.
2.11
1.67
34 out of 37 countries
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Evaluating the Buss Study

• What are the independent and dependent variables
  in this study?
• Is the study an experiment?
• What are possible problems with internal
  validity?
• Direction of causality?
• Lurking variables?