9. Taking painkillers
Painkillers really help those who have chronic pain. However, in research conducted by the University of Ohio it was shown that painkillers can also decrease the sharpness of good emotions.
In this research, one group of participants took painkillers and the other took a placebo that looked the same. Later, the participants looked at 40 photographs — from very unpleasant (starving children) to very cute (children playing with cats). After every photo, the participants had to estimate how positive certain photos were.
The results showed that the participants who took painkillers estimated that the photos were worse than those who took the placebo. In other words, the emotional perception of reality was distorted.