There is a third particularly frequent and important case of symptom formation, in which the identification leaves any object relation to the person who is being copied entirely out of account. Supposing, for instance, that one of the girls in a boarding school has had a letter from someone with whom she is secretly in love which arouses her jealousy, and that she reacts to it with a fit of hysterics; then some of her friends who know about it will contract the fit, as we say, by means of mental infection. The mechanism is that of identification based upon the possibility or desire of putting oneself in the same situation. The other girls would like to have a secret love affair too, and under the influence of a sense of guilt they also accept the pain involved in it. It would be wrong to suppose that they take on the symptom out of sympathy. On the contrary, the sympathy only arises out of the identification, and this is proved by the fact that infection or imitation of this kind takes place in circumstances where even less pre-existing sympathy is to be assumed than usually exists between friends in a girls' school. One ego has perceived a significant analogy with another upon one point--in our example upon a similar readiness for emotion; an identification is thereupon constructed on this point, and, under the influence of the pathogenic situation, is displaced on to the symptom which the one ego has produced. The identification by means of the symptom has thus become the mark of a point of coincidence between the two egos which has to be kept repressed. What we have learned from these three sources may be summarised as follows. First, identification is the original form of emotional tie with an object; secondly, in a regressive way it becomes a substitute for a libidinal object tie, as it were by means of the introjection of the object into the ego; and thirdly, it may arise with every new perception of a common quality shared with some other person who is not an object of the sexual instinct. The more important this common quality is, the more successful may this partial identification become, and it may thus represent the beginning of a new tie. We already begin to divine that the mutual tie between members of a group is in the nature of an identification of this kind, based upon an important emotional common quality; and we may suspect that this common quality lies in the nature of the tie with the leader. Another suspicion may tell us that we are far from having exhausted the problem of identification, and that we are faced by the process which psychology calls 'empathy [_Einfühlung_]' and which plays the largest part in our understanding of what is inherently foreign to our ego in other people. But we shall here limit ourselves to the immediate emotional effects of identification, and shall leave on one side its significance for our intellectual life.