Final answer:
Exposure to longer hours of bright light that regulate the circadian rhythm leads to improved mood and happiness.
Step-by-step explanation:
The phenomenon you are referring to is known as the circadian rhythm. The circadian rhythm is an internal biological process that controls the sleep-wake cycle and is influenced by exposure to light. When individuals are exposed to longer hours of bright light, it helps regulate their circadian rhythm, leading to improved mood and a sense of happiness. This is because bright light exposure stimulates the production of serotonin, a neurotransmitter that is associated with feelings of well-being.
For example, individuals who work night shifts or are affected by seasonal variations in light can use devices like lightboxes to provide exposure to bright light and help maintain a regular circadian cycle, leading to improved mood and happiness.