Describe the procedure of the study carried out by Green (1968)
- Male university students had to complete a jigsaw puzzle, but their levels of frustration were manipulated
- In one group the puzzle was impossible to solve, in another they ran out of time because a confederate kept interfering and the last group were insulted by the confederate as they failed to solve the puzzle
- The participants then had to issue electric shocks to confederate when they made a mistake on another task