According to sexual selection, traits attractive in a mate will become more common over time, as the individual animals that display those traits pass on their genes more often than animals that don't. Sexual selection can lead to traits that don't have a direct survival advantage but serve to advertise the fitness of their bearer's genes.
In the test conducted:
...men became more creative whether they were looking at photos, imagining short-term liaisons or envisioning a long-term partner. The women, however, showed substantial increases in creativity only when they imagined devoted long-term partners.
In most animal species, males display sexually selected traits while females select for them—the classic example being the brightly colored tail of the peacock, which is displayed only by males.
Martie Haselton, an evolutionary psychologist at the University of California, Los Angeles, said the study's findings about the relationship between romance and creativity—and about males' disproportionate display of romance-inspired creativity—provide a significant boost to the sexual selection theory of creativity.
Read the Seed Magazine article: Men and Sometimes Women Lure Mates Creatively