Conclusion: The study suggests that bystander apathy is not due to indifference, but rather to situational factors, such as diffusion of responsibility.

Strengths: The study used a field experiment, which increased the ecological validity of the findings.

The study involved a large sample size, increasing the generalizability of the findings.

Weaknesses: Ethical concerns about deception.

The study's findings may be limited to the specific context of the study (a New York City subway train).

The study used a staged event, which may not be generalizable to real-life situations.

Psychology Investigated: Prosocial behavior and instrumental helping in chimpanzees.

Background: Previous research had suggested that chimpanzees are capable of altruistic behavior.

Aim: To investigate whether chimpanzees are capable of helping another chimpanzee based on their specific needs.

Procedure: Two chimpanzees were placed in adjacent enclosures.

One chimpanzee was given a tool that they needed to access a reward.

The other chimpanzee was given a different tool that they did not need.