A little before and during the winter and summer solstices, the sun appears to rise and set at almost exactly the same places. In our bodies the pineal gland governs some of the internal cycles that are in sync with the seasonal movements of the sun. As the days shorten, the pineal secretes melatonin that controls the seritonin levels in the brain and when elevated amounts are released over a period of time, it triggers depression. As the days grow longer the process reverses. The pineal gland is sensitive to light and along with the rest of the endocrine system, acts to trigger the body into keeping in unison with the environment .
Animals follow precise seasonal patterns of mating, hibernation and migration.
All three are linked to seasonal differences in sunlight. A lot that is done by instinct by animals is culturally motivated in people. Social patterns tie people to their culture and culture to nature. An example is the aborigines. For generations they have followed the same imperceptible paths which have been communicated through song and memorized for generations.