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

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 learnt2. Motivation (to achieve a goal)3. Exploration – either random or purposeful4. 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

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)

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