Which type of crowd is best characterized as having a common purpose and collective behavior?

The type of crowd that is best characterized by having a common purpose and collective behavior is the mob. A mob typically forms around a shared goal or feeling, often driven by strong emotions or a collective intention, such as protest or social action. This shared purpose creates a sense of unity among its members, leading to coordinated actions that reflect their common interests or grievances.

In contrast, a casual crowd is generally formed without any cohesive objective, lacking the defined purpose that characterizes a mob. A coherent crowd, while it may exhibit some level of organization, does not reach the intensity or emotional fervor that a mob typically demonstrates. Lastly, a riot represents a form of crowd behavior marked by chaos and violence, which can sometimes emerge from mob dynamics but does not inherently emphasize the common purpose aspect in the same way a mob does. The fundamental aspect of a mob lies in its collective drive toward a specific cause or behavior, setting it apart from other types of crowd formations.