Early light, early birds and early parties: light exposure and our biological clock influence our happiness less than thought. In her dissertation, Anne Landvreugd also debunks a popular myth.
Landvreugd: "In the summer you hear a lot of people say: I feel so much better now that there is more light again. But does it really work that way? We wanted to be sure. A lot of research has already been done on the link between light and clinical depression. But we wondered about the relationship between light and our feeling of happiness in an everyday setting. And what role does our biological clock and our DNA play in our well-being?"
"We found that light exposure can have a small to moderate positive impact on how we feel. So that effect is not great, but it is there. It also appears that people with a genetic predisposition to be 'morning person' experience slightly fewer depressive symptoms on average. But according to our research such a genetic predisposition does not lead to greater well-being or happiness."
Social jetlag
"We also took a close look at social factors such as work and sleep schedules. For example, we discovered that 'social jetlag' - the difference in sleep on working days and days off - is only minimally related to the feeling of well-being."
"This is in line with a striking social trend: the shift from night parties to early parties during the day. Where it was often thought that 'social jetlag' is harmful, this effect on happiness appears to be minimal. Complaints that occur after going out are more likely to be caused by pure sleep deprivation and substance use than by the time of the party. Whether you dance at 22:00 or at 05:00 makes less difference to your well-being than we thought.
'Not a panacea'
"All taken together, our research shows that light exposure and the biological clock are important for mental health, but are not a panacea for increased happiness. Rather, this is a result of a complex interplay of factors, and also depends on genetic predisposition, daily activities and individual differences."
More information on the thesis
