May 2

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May 2
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Clark Hulls (1943) Drive Theory

• Excitatory Potential Drive x Habit Strength
• (E D x H)

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Habit HierarchiesD X H

• If Drive 1, var 1
• H1 4.0 E 4.0
• H2 3.5 E 3.5
• H3 3.1 E 3.1
• H4 3.0 E 3.0
• H5 2.0 E 2.0
• H6 1.0 E 1.0

• If Drive 10, var 1
• H1 4.0 E 40
• H2 3.5 E 38
• H3 3.1 E 34
• H4 3.0 E 30
• H5 2.0 E 20
• H6 1.0 E 10

Frequency/ ? Probability
E ?
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Clark Hulls (1943) Drive Theory

• In a given situation, possible responses vary in
  habit strength, creating a habit hierarchy
• As drive increases, responses highest in the
  habit hierarchy (dominant responses) become more
  and more likely to occur, at the expense of
  non-dominant responses
• Increases in drive facilitate
• Dominant Responses

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Drive, Task Complexity, and Performance

• On simple, familiar tasks, the dominant response
  is correct
• On difficult, novel tasks, the dominant response
  is incorrect
• As drive increases, performance improves on
  simple tasks and deteriorates on difficult tasks

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Drive, Task Complexity, and Performance

• Simple and complex tasks can be used to detect
  changes in drive (arousal)
• The Stroop task (Stroop Stroop)
• Cat Girl Wagon Girl Cat Wagon
• Red Blue Green Green Red Blue
• Red Blue Green Blue Red Blue

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Aspects of Good Theory

• Explanation
• A good theory explains a large amount of what we
  already know (about what people do)
• Prediction
• A good theory allows us to predict what will
  happen (what people will do)
• Control
• A good theory tells us how to change (what people
  do)

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Aspects of Good Theory

• Falsifiable
• A good theory can be shown to be wrong it is
  testable
• Boundary Conditions
• No theory explains everything a good one
  specifies when it applies and when it does not
• Heuristic Value
• A good theory leads us to ask questions that
  otherwise would not have occurred to us

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The Process of Theory Development

• We have some theories, relatively old, that have
  stood the test of time and are well understood
• Current theories are in the process of testing
  and challenging here we tolerate much more
  uncertainty
• New findings will often change the way we think
  about things, even older well-established
  theories
• Our current best wrong theory is what we are
  typically using at the frontiers of knowledge

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Changing Gears The Effects of Groups on
Performance

• Question do people perform better when they are
  alone, or with others?
• Two paradigms
• Coaction (all engaged in the same activity)
• Audience (being observed by others)

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Triplett (1898)
Triplett noticed that cyclists were faster
racing in groups than against the clock
Coaction
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Triplett (1898)
Audience
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Triplett (1898)

• Triplett theorized that racing together releases
  the competitive instinct, increases arousal, and
  improves performance
• Consistent with this hypothesis, when children
  were asked to wind fishing reels, either by
  themselves or in groups (coaction), those in
  groups wound faster

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Effects of Groups on Performance

• Unfortunately, many subsequent studies of
  performance alone and in groups generated a very
  inconsistent set of findings sometimes
  performance was better in groups, sometimes it
  was better when alone

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The Zajonc solution

• Robert Zajonc
• Zajonc
• Science
• Zajonc, R.B. (1965). Social facilitation.
  Science, 149, 269-274.
• Hypothesis The mere presence of conspecifics is
  a source of arousal.

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Zajonc (1965) Theory of Social Facilitation
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Blatta Orientalis
Photophobic
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Zajonc, Heingartner, Herman (1969)
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Zajonc, Heingartner, Herman (1969)
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Zajonc, Heingartner, Herman (1969)
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Zajonc, Heingartner, Herman (1969)
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Zajonc, Heingartner, Herman (1969)
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Zajonc, Heingartner, Herman (1969)
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Zajonc, Heingartner, Herman (1969)
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Zajonc, Heingartner, Herman (1969)
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Zajonc, Heingartner, Herman (1969)
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Zajonc, Heingartner, Herman (1969)
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Zajonc, Heingartner, Herman (1969)
Dependent Variable Running time in seconds
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Zajonc, Heingartner, Herman (1969)
Dependent Variable Running time in seconds
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Zajonc, Heingartner, Herman (1969)
Dependent Variable Running time in seconds
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Zajonc, Heingartner, Herman (1969)
Dependent Variable Running time in seconds
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Zajonc, Heingartner, Herman (1969)
Dependent Variable Running time in seconds
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Social Facilitation (Zajonc, 1965)

• Zajonc argued that it is the mere presence of
  others that causes increased arousal
• Large number of studies consistent with this
  position
• Others have suggested that with humans more than
  mere presence is required
• Evaluation apprehension
• Social facilitation only occurs when those others
  are seen as potential evaluators