Transference
Transference is a phenomenon in psychology characterized by unconscious redirection of feelings for one person to another. One definition of transference is "the inappropriate repetition in the present of a relationship that was important in a person's childhood." Another definition is "the redirection of feelings and desires and esp. of those unconsciously retained from childhood toward a new object." Still another definition is "a reproduction of emotions relating to repressed experiences, esp. of childhood, and the substitution of another person . . . for the original object of the repressed impulses." Transference was first described by Sigmund Freud, who acknowledged its importance for psychoanalysis for better understanding of the patient's feelings.
It is common for people to transfer feelings from their parents to their partners (emotional incest) or to children (cross-generational entanglements). For instance, one could mistrust somebody who resembles an ex-spouse in manners, voice, or external appearance; or be overly compliant to someone who resembles a childhood friend.
In The Psychology of the Transference, Carl Jung states that within the transference dyad both participants typically experience a variety of opposites, that in love and in psychological growth, the key to success is the ability to endure the tension of the opposites without abandoning the process, and that this tension allows one to grow and to transform.
Transference is common. Only in a personally or socially harmful context can transference be described as a pathological issue.
A new theory of transference known as AMT (Abusive Multiple Transference) has been suggested by David W. Bernstein, in which abusers not only transfer negative feelings directed towards their former abusers to their own victims, but also transfer the power and dominance of the former abusers to themselves. This kind of transference is sometimes part of the psychological makeup of murderers -- for example the serial killer Carroll Cole. While his father was away in World War II, Cole's mother engaged in several extra-marital affairs, forcing Cole to watch. She later beat him to ensure that he would not alert his father. Cole would later come to murder many women whom he considered "loose," and those in general who reminded him of his mother. AMT also ties in very closely with Power/Control Killers, as the feeling and view of control is passed from one abuser to those succeeding him or her.

# Transference and counter-transference during psychotherapy
In a therapy context, transference refers to redirection of a client's feelings from a significant person to a therapist. Transference is often manifested as an erotic attraction towards a therapist, but can be seen in many other forms such as rage, hatred, mistrust, parentification, extreme dependence, or even placing the therapist in a god-like or guru status.  When Freud initially encountered transference in his therapy with clients, he felt it was an obstacle to treatment success.  But what he learned was that the analysis of the transference was actually the work that needed to be done.  The focus in psychodynamic psychotherapy is, in large part, the therapist and client recognizing the transference relationship and exploring what the meaning of the relationship is.  Because the transference between patient and therapist happens on an unconscious level, psychodynamic therapists who are largely concerned with a patient's unconscious material use the transference to reveal unresolved conflicts patients have with figures from their childhoods.
Counter-transference is defined as redirection of a therapist's feelings toward a client, or more generally as a therapist's emotional entanglement with a client.  A therapist's attunement to their own countertransference is nearly as critical as their understanding of the transference.  Not only does this help the therapist regulate his/her own emotions in the therapeutic relationship, but it also gives the therapist valuable insight into what the client is attempting to elicit in them.  For example, if a male therapist feels a very strong sexual attraction to a female patient, he must understand this as countertransference and look at how the client is attempting to elicit this reaction in him.  Once it has been identified, the therapist can ask the client what their feelings are toward the therapist and examine the feelings the client has and how they relate to unconscious motivations, desires, or fears.
Another contrasting perspective on transference and counter-transference is offered in Classical Adlerian psychotherapy.  Rather than using the client's transference strategically in therapy, the positive or negative transference is diplomatically pointed out and explained as an obstacle to cooperation and improvement.  For the therapist, any signs of counter-transference would suggest that his/her own personal training analysis needed to be continued to overcome these tendencies.