People are likely to invest less effort in a task when they are working with others. What is this phenomenon called?

This phenomenon is known as "social loafing." Social loafing refers to the tendency for individuals to put forth less effort when they are part of a group compared to when they are working alone. The concept suggests that when individuals work in a group, they may feel less personally responsible for the outcome of the task, leading to a decrease in their overall contribution effort.

This behavior can be attributed to several psychological mechanisms, including diffusion of responsibility, where individuals feel less accountable in a group setting, and the expectation that others will compensate for their lack of effort. Social loafing can negatively impact group performance and productivity. To mitigate social loafing, it is essential to establish clear individual roles, set group goals, and create a strong sense of accountability among team members.