Creativity researchers have recently sought to standardize idea assessment via computational measures of semantic distance: the degree of conceptual dissimilarity between words. The relationship between semantic distance and creativity has traditionally been described using linear models, with the embedded assumption that as semantic distance increases, so does the creative quality of ideas. However, informal observations would suggest that distant associations may sometimes become too incoherent or nonsensical to be considered creative. Using generalized additive models (GAMs), we explored the non-linear nature of this relationship across three divergent thinking tasks: alternate uses, question asking, and metaphor generation. Our results revealed a consistent pattern: human ratings of creativity increased with semantic distance up to a certain threshold (between 0.9 and 1), after which point, additional semantic distance did not translate into more subjectively creative ideas. These findings provide a more nuanced understanding of the interplay between semantic distance and creativity than previously available, suggesting that the relationship is best characterized as curvilinear rather than linear. This work highlights a potential "sweet spot" for semantic distance in creative ideation and holds important implications for models of creativity.