• Social loafing refers to the phenomenon where individuals exert less effort when working in a group compared to when working alone. In the example, as the group size increased, the individual contribution to the overall noise decreased. This reduction in effort per person is a classic case of social loafing.
• Social facilitation is the tendency for people to perform better on simple tasks in the presence of others, which is not applicable here since the individual effort decreases.
• Social rejection refers to being excluded or dismissed from a group, which does not relate to the context of this question.
• Social participation refers to involvement in activities within a community or group, which also does not apply to the reduced effort phenomenon observed.