A Map of Human Temperament to the Calendar Year

A speculative essay, in the scientific tradition of ever more granular human behaviors falling into a reductionist paradigm, where, in addition to the previously established human behavioral patterns tracked to the annual sunlight-driven dopamine cycle, a second dopamine “clock” or cycle is proposed in the human brain. This measured cycle occurs starts with a 10-day-long “low dopamine” phase (with various stages of impulsivity, anxiety, and depression and then the reverse as dopamine levels climb back up), then a 10-day-long “high dopamine” phase (with hyperactive and manic behaviors), before diminishing to a 20-day-long “normal dopamine” phase (with calm and focus), before the cycle starts again with the “low dopamine” phase. The levels of the primary sunlight-driven cycle and the proposed secondary dopamine cycle aggregated together are considered as the only factors needed to create a calendar map of “human temperament.” Evolutionary fitness benefits are discussed as possible causes of the secondary cycle and its amplitude considered as driving behaviors due to changes to (or limits to) working memory.