Idea evaluation plays a crucial role in creativity and innovation and is influenced by evaluator self-interested preferences for endorsing or opposing a creative idea. Evaluator preferences drive motivated perceptions of cues such as novelty as well as differences in the effect those cues have on idea endorsement. However, because such motivated reasoning uses limited cognitive resources, increasing cognitive load weakens the relationship between evaluator preferences and perceptions of cues such as novelty. Increasing evaluator cognitive load also reduces self-perceived evaluative ability, attenuating evaluator’s response actions. Reduced evaluative ability increases endorsement of ideas that are inconsistent with evaluator preferences and decreases endorsement of ideas that are consistent with evaluator preferences. Therefore, increasing cognitive load during evaluation can be both productive and counterproductive for idea endorsement, as moderated by evaluator preferences. Additionally, evaluator preferences and perceptions influence when emphasizing a cue such as novelty has positive, negative, and no impact on idea endorsement. These relationships are tested across five studies in which workers evaluate and indicate their endorsement of real-world technological ideas that their organization is likely to implement. Implications for theory and practice are discussed.