Dreams record how people live, think, and relate to their surroundings. Large collections of dreams can be analysed to understand group differences. We compared 2,337 dream reports — 1,169 from people with synesthesia and 1,168 from controls.

For people with synesthesia, certain types of information automatically trigger additional sensations. For example, some see colours when reading letters, taste flavours when hearing words, or picture numbers arranged in space. People with synesthesia also tend to score higher on imagination, creativity, and openness.

Our analysis tested whether these enduring traits were reflected in dream content. Four themes occurred more often in the dreams of people with synesthesia: digital routines involving online activity, guilt and repair where people tried to make amends, conflict and threat such as pursuit or confrontation, and changing worlds that moved between varied and unusual settings.

The results show that recurring dream patterns correspond with known individual differences, demonstrating that dream data can be used to study how distinct populations experience waking reality.