This 4 slide file accompanies a youtube clip (see www.ePsychVCE.com to access link to clip). It covers Thorndike's Puzzle box experiment an his infamous 'law of effect'

1. Thorndike
• Interested in studying
animal intelligence
• He found that animal
intelligence is based on
the ability to form
connections
• Set up puzzle-box
experiments to
investigate instrumental
conditioning

2. Trial & Error learning - Thorndike
• Describes an organism’s attempts to
learn/solve a problem by trying alternative
possibilities until a correct solution or
desirable outcome is achieved
Usually involves
1. A number of attempts & a number of errors
- Before correct behaviour is learnt
2. Motivation (to achieve a goal)
3. Exploration – either random or purposeful
4. Reward – the correct response is rewarded –
• which will lead to repeat performance of
the correct response, strengthening the
association between the behaviour & its
outcome
• Once learnt behaviour will usually be
performed quickly and with fewer errors

3. Thorndike’s Puzzle-box experiment
• Thorndike put a hungry cat in a
‘puzzle box’ & placed fish, just
out of reach
1. At first the cat to escape from the
box through trial & error
(random voluntary movements)
2. Eventually the cat accidentally
pulled the string, escaped from
the box so that it could reach its
reinforcement (the fish)
• When the cat was put back in the
box, once again it went through a
series of incorrect responses
before pushing the lever
• The cat became progressively
quicker at escaping (and had
fewer incorrect behaviours)

4. Thorndike ‘Law of Effect’
• Thorndike concluded that the cat had
learned the association between its
behaviour (pulling the string) & the
consequences (reaching the food)
• Results led Thorndike to devise the
‘Law of effect’ that is a behaviour
that is followed by a satisfying
consequence is strengthened (more
likely to happen) than a behaviour
that is followed by an annoying
consequence which is weakened (less
likely to occur)
• The food was a satisfying
consequence – hence the cat would
try to escape
• Behaviour that kept the cat in the
box (annoying consequence) was less
likely to occur