Transference
Transference is considered one of the most important events in some schools of psychology. Normally it is defined very narrowly to refer to something that occurs between a "patient" and a "doctor". On this website, transference will have broader definition.
One (online) definition of the transference is "In psychoanalysis, the process by which emotions associated with one person, such as a parent, unconsciously shift to another, especially to the analyst."
Here the definition is expanded to mean any substitution of one thing (person, etc) for another. The point of the broader definition will be to show that transference occurs with almost every relationship a person has, and trying to trace our reactions back to their original root is the beginning of psychology.