Final answer:
The interaction pattern that involves cooperative actions by individuals within a group to achieve a shared goal is referred to as Intragroup interaction. This concept is related to addressing collective action problems within groups to accomplish common objectives.
Step-by-step explanation:
The interaction pattern that encompasses a cooperative action by at least two persons to achieve a mutual goal is known as Intragroup interaction. Intragroup interactions involve members within a single group who work together to pursue common objectives. This is in contrast to intergroup interactions, which occur between different groups, or unilateral actions which are taken by a single person or entity without the cooperation of others.
Collective action problems arise when individuals within a group would benefit from cooperating, but have incentives not to. These problems can be particularly challenging when group members have different opinions or when personal motivations conflict with the group's goals. However, when solved effectively within groups, especially small ones, collective action can lead to accomplishing shared objectives as members are compelled to contribute equitably.