Apropos of certain pictures, it has been my experience that lighting affects mood. This could be my imagination, but it seemed to affect more than just me. At work, the walls were changed from white to brown (think cheap 70's motel), which made the building appear much darker. The lights were then replaced with brighter lights, which restored some of the original brightness, but made the dirt on the walls more evident. Recently, the lights were changed from fluorescent to LED, which are brighter, yet, but have a slight bluish hue. Because of the type of lighting, there are more shadows. Each change of lighting has affected the mood of the people. Since the lighting changes were each in effect for 6 months or more, this was more of a long-term thing.
My observation has been that health closely follows the mood. Several people at work leave their rooms very dimly lit, and these people are out sick more than anyone else in the building. People who live in dim lighting seem to find more depressing things on which to dwell. Although there are exceptions, it seems that happy people are happy, but people who have slight depression issues will experience an exacerbation of these issues, when living in poor lighting.
Over the last 15 years, we completed a county-wide study on lighting. Eprirical evidence from that study suggests that the most healthy, productive people use natural lighting, get the best sleep, and have a positive outlook. In contrast, dim lighting had the opposite results. The study found that these results spread across income brackets. The study also found that people who used social media were less likely to have a positive outlook, and contributed less to society.
Humorously, the group that commissioned the report is rejecting key portions of the report, because the results also show that many "healthy" initiatives were actually unhealthy. Case in point, a team of people pushing the initiatives had to cease practicing those initiatives, for health reasons.
