Group decision-making (also known as collaborative decision-making or collective decision-making) is a situation faced when individuals collectively make a choice from the alternatives before them. The decision is then no longer attributable to any single individual who is a member of the group. This is because all the individuals and social group processes such as social influence contribute to the outcome. The decisions made by groups are often different from those made by individuals. In workplace settings, collaborative decision-making is one of the most successful models to generate buy-in from other stakeholders, build consensus, and encourage creativity. According to the idea of synergy, decisions made collectively also tend to be more effective than decisions made by a single individual. In this vein, certain collaborative arrangements have the potential to generate better net performance outcomes than individuals acting on their own. Under normal everyday conditions, collaborative or group decision-making would often be preferred and would generate more benefits than individual decision-making when there is the time for proper deliberation, discussion, and dialogue. This can be achieved through the use of committee, teams, groups, partnerships, or other collaborative social processes.
However, in some cases, there can also be drawbacks to this method. In extreme emergencies or crisis situations, other forms of decision-making might be preferable as emergency actions may need to be taken more quickly with less time for deliberation. On the other hand, additional considerations must also be taken into account when evaluating the appropriateness of a decision-making framework. For example, the possibility of group polarization also can occur at times, leading some groups to make more extreme decisions than those of its individual members, in the direction of the individual inclinations. There are also other examples where the decisions made by a group are flawed, such as the Bay of Pigs invasion, the incident on which the groupthink model of group decision-making is based.
Factors that impact other social group behaviours also affect group decisions. For example, groups high in cohesion, in combination with other antecedent conditions (e.g. ideological homogeneity and insulation from dissenting opinions) have been noted to have a negative effect on group decision-making and hence on group effectiveness. Moreover, when individuals make decisions as part of a group, there is a tendency to exhibit a bias towards discussing shared information (i.e. shared information bias), as opposed to unshared information.