Researchers investigated whether the level of physical crowding in a subway carriage influences the likelihood of passengers intervening when a stranger is being verbally harassed.
A sample of 120 passengers (60 males and 60 females) was observed across several journeys on a metro line in a major city. The independent variable was the crowding level of the carriage, classified as either 'high density' (more than 40 standing passengers) or 'low density' (fewer than 10 standing passengers).
A female confederate and a male confederate sat opposite each other. The male confederate began to loudly and aggressively argue with the female confederate about playing music too loudly, creating a tense situation. A third observer (covertly sitting nearby) recorded whether any passenger intervened (either verbally or by physically stepping in between them), the gender of the intervening passenger, and the time taken (in seconds) before someone intervened.
The passengers were unaware they were part of a study.
Explain one weakness of using a field experiment for this study on prosocial intervention.
Practise Edexcel A Level Psychology Research methods and skills with exam-style questions for A Level Psychology. 657 questions covering Research methods and skills, matched to the Edexcel A Level Psychology (9PS0) specification and written in Paper 1, Paper 2 and Paper 3 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.
