[C] Loftus and Palmer

Aim

• Investigation on how provided information can influence eye witness testimony

Experimental Method + Design

• 2 Lab experiments

• IMD

Experiment 1: Sample

• 5 groups of 9 = 45 ppts

Experiment 1: IV and DV

• IV: Critical word used (Smashed, Collided, Bumped, Hit, Contacted)

• DV: MPH speed of car

Experiment 1: Method

• Watched a short car crash clip

• Each asked: ‘How fast were the cars going when they [__] each other’

• Each group given a different verb: Smashed, Collided, Bumped, Hit, Contacted

Experiment 1: Results

• Highest: Smashed (40.8)

• Lowest: Contacted (31.8)

Experiment 2: Sample

• 3 groups of 50 = 150 ppts

Experiment 2: IV and DV

• IV: smashed/hit/[not asked]

• DV: Broken glass recall

Experiment 2: Method

• Watched a short multi-vehicle car crash clip

• 3 groups:

  • 1) Asked ‘How fast were the cars going when they smashed each other’

  • 2) Asked ‘How fast were the cars going when they hit each other’

  • 3) Not asked anything

• 1 Week later → asked if they saw any broken glass

  • No broken glass was in the film

Experiment 2: Results

• Highest: Smashed (16/50 saw glass)

• Lowest: Control (6/50 saw glass)

Conclusions

• Language (the verb used)/misleading info influences post-event memory → eye witness testimony is faulty

  • Leading questions alter memory

• People do not reliably judge vehicle speeds