Working with loss and bereavement has a high potential for burnout. before workers engage in grief work with others, they must first take care of themselves by maintaining their vitality, failure to do so can result as vicarious traumatization.

i believe the answer is:   psychological  experiment

in this experiment, wilhelm wundt became the first person that implement scientific method in analyzing the pyschological phenomenon.

due to this result, wilhelm wundt also able to make psychology to be acknowledged as a separate scientific field from biology.