The extent to which groups are creative has wide implications for their overall performance, including the quality of their problem solutions, judgments, and decisions. To further understanding of group creativity, we integrate the motivated information processing in groups model (De Dreu, Nijstad, & Van Knippenberg, 2008) with work on epistemic social tuning (Lunn, Sinclair, Whitchurch, & Glenn, 2007). Three propositions were advanced: (a) Groups produce more ideas when members have high rather than low epistemic motivation, especially when members also have a prosocial rather than pro-self motivation; (b) these ideas are more original, appropriate, or feasible when a group norm favors originality, appropriateness, or feasibility; and (c) originality is valued more in individualistic cultures (e.g., the Netherlands), whereas appropriateness is valued more in collectivist cultures (e.g., Korea). Four studies involving 3-person groups generating ideas supported these propositions: Epistemic motivation (mild vs. intense time pressure; presence vs. absence of process accountability) stimulated production and originality, especially when prosocial rather than pro-self motives were present and participants were Dutch or originality norms were experimentally primed. When appropriateness norms were primed or participants were Korean, epistemic motivation stimulated production and appropriateness, especially when prosocial rather than pro-self motives were present. We discuss implications for research on group processes and for work on culture and creativity.