Social loafing is a similar effect; it happens when we don't devote as much to a task because our contribution is part of a larger group effort.37 You may have experienced this if you've worked on a group project for a class! Waitpersons are painfully aware of social loafing: People who eat in groups tend to tip less per person than when they eat alone.38 For this reason, many restaurants automatically tack on a fixed gratuity for groups of six or more.