We often consider spreading responsibility in an emergency. However, it can also happen in everyday situations. For example, the spread of responsibility can explain why you may not be involved in a group project as you would on a particular project (because your classmates are also responsible for the job). This can also explain why it is difficult to share housework with roommates: you may want to put these dishes in the sink, especially if you don’t remember if you were the last person to use them. In other words, the spread of responsibility is not just what happens in an emergency: it also happens in our daily lives. In an emergency, if there are other people, why are we less likely to help? One reason is that an emergency is sometimes ambiguous. If we are not sure if there is an emergency (especially if other people present do not seem to care about what is happening), we may be concerned if there is no emergency that may actually result in a “false positive”.