Final answer:
Groups are characterized by shared interactions and identity, with small groups being cohesive but limited in influence and larger groups having more impact but potential internal division. Group dynamics, such as structure and leadership style, significantly affect how a group functions.
Step-by-step explanation:
One characteristic of a group is that it tends to encompass individuals who often interact with some regularity and sense a shared identity related to the group. Groups are defined by various traits, such as size, formality, and the levels of connectedness between its members. The dynamic within any given group can be influenced by its size, from small formations like dyads and triads to large, sprawling collectives that may spread globally.
Small groups have a strong sense of cohesion and can readily cultivate a shared sense of purpose among members. However, as groups become larger, they have the potential to exert more influence and achieve larger goals, albeit with an increased risk of internal division and a reduction in overall cohesion. Group dynamics are essential in understanding how such collectives function, with factors such as leadership styles and group structure playing significant roles in their operation.