Topic 3 - Mann et al - Lie detection technique

Question 1

What was the aim?

Answer 1

To test police officers’ ability to distinguish truth and lies during police interviews with suspects.

Question 2

What was the research method?

Answer 2

Field experiment

Question 3

What was the sample?

Answer 3

99 Kent Police officers, 24 female, 75 male, mean age 34.3, 78 were detectives, 4 training officers, 9 uniformed response officers

Question 4

What was the procedure?

Answer 4

14 suspects head and torso, backed up with evidence, 54 clips ranged from 6-145 seconds, asked to judge truthfulness of people in real-life police interviews, officers then had to fill in a questionnaire about experience in detecting liars, watched clips and said if truth or ie and how confident, asked for cues.

Question 5

What were the results?

Answer 5

Difference between mean lie accuracy (66.2%) and truth accuracy (63.6%) 0 not significant but both were greater than chance - experience in interviewing was correlated with truth accuracy and lie accuracy

Question 6

What were the conclusions?

Answer 6

Levels of accuracy found in study exceeds those found in other studies (highest for group of ordinary police officers) - more experience an officer has (by own self report) = better at detecting lies