Being outside in the sun has many positive effects on well-being and health. However, there is limited knowledge about its effects on human behavior. However, there are metaphorical relationship between light and goodness and darkness and unethical behavior.
In a study with the interesting title “In broad daylight we trust in God. Brightness the salience of morality and ethical behavior” researchers at National Sun Yat-sen University in Taiwan explored the effects of different light intensities on several aspects of human behavior.
81 undergraduate students were randomized to either high, medium, or low brightness The study participants then conducted four different tests.
The dictator game: The game consists of two people. One of them receives an amount of money and is asked to share what he or she believes is fair with the other person. The other person does not know how much money the person who first received the money got.
On average the one who receives money only gives about 40% to the other person and keeps 60%.
In this particular study, people acted less selfishly in brighter light compared to reduced brightness.
The researchers also put money in various places in the room. Study participants in bright light were more likely to return money they found, compared to participants in a room with moderate or low brightness.
In the second test study participants were asked to donate money to charity. The brighter the room was lit the more Taiwanese dollars the study participants donated, 19 in low lit room, 29 in moderate brightness and 41 in the most bright room.
In the third experiment, the study participants were asked to volunteer with coding data, a rather uninteresting job. However, the brighter the room was lit the longer the participants endured with this boring activity.
This study seems to suggest that light may promote goodness (volunteering longer, donated more money) and just behavior (more equal sharing of money, and return money that were not their own).
This resembles the fruit of the light that Paul describes in Ephesians.
The fruit of the light consists in all goodness, righteousness and truth
Paul (Eph 5:9)
Paul explains how the readers used to be in darkness, mentioning behaviors such as sexual immorality, greed, obscenity, and coarse joking. However, when we follow Jesus, “the light of the world” we will show goodness, speak truth, and act just toward people around us.
In another study researchers observed that bright light promotes
- Reflection instead of impulsivity
- Reflective self-regulation
- Automatic inhibition of desires and impulses
With the limited research that has been conducted in this area, it is probably too early to conclude on the behavioral effects of sunlight. However, there are at least some indications that light may influence our behavior toward desired traits, such as less selfish, care more about other people, and act more just and honest
I find it interesting to observe that physical light seems to have some of the same effects on human behavior as spiritual light does. It is therefore unfortunate that exposure to both physical light and the light that Paul is speaking about has declined during the last 200 years, particularly in western countries. This will be explored in another blog post.
God saw that the light was good
Genesis 1:4
Sources
- Chiou, Wen-Bin, and Ying-Yao Cheng. “In broad daylight, we trust in God! Brightness, the salience of morality, and ethical behavior.” Journal of Environmental Psychology 36 (2013): 37-42. (Link)
- Steidle, Anna, and Lioba Werth. “In the spotlight: Brightness increases self-awareness and reflective self-regulation.” Journal of Environmental Psychology 39 (2014): 40-50. (Link)
