Two or more people in interacting situations will over time develop stable territorial relationships. As described above, these may or may not develop into groups. But stable groups can also break up in to several sets of territorial relationships. There are numerous reasons for stable groups to "malfunction" or to disperse, but essentially this is because of loss of compliance with one or more elements of the definition of group provided by Sherif. The two most common causes of a malfunctioning group are the addition of too many individuals, and the failure of the leader to enforce a common purpose, though malfunctions may occur due to a failure of any of the other elements (i.e., confusions status or of norms).