Color qualia—the subjective experience of color, such as the quality of redness—are similar across age and culture. Using a task that obtained pairwise similarity judgments via intuitive visual interfaces, researchers tested children aged 3 to 12 in Japan and 6 to 8 in China, comparing them with Japanese adults. About half of 3-year-olds completed the touch-panel task reliably. Despite developmental and cultural differences in color-term usage, color qualia structures were quite similar across all groups. This suggests that these structures emerge early in life. Subtle age-related differences in evaluations of some color pairs imply minor changes in color experience with development.
Hallucinations, which occur in many psychiatric disorders, may be better understood through the lens of developmental psychology. Their clinical significance depends on when they appear in a person's life. Key cognitive-developmental processes—such as engaging with imaginary entities, adverse events, executive functioning, social cognition, and language development—shape how hallucinations arise across different sensory modalities. Atypical developmental trajectories, as seen in certain conditions, also influence hallucination prevalence and phenomenology. Integrating developmental and psychiatric perspectives could yield mutual benefits for future research.