finally caught.  In considering the “Analysis of the Sexual Impulse” we found that the primary part of the male in courtship is by the display of his energy and skill to capture the female or to arouse in her an emotional condition which leads her to surrender herself to him, this process itself at the same time heightening his own excitement.  In the playing of these two different parts is attained in both male and female that charging of nervous energy, that degree of vascular tumescence, necessary for adequate discharge and detumescence in an explosion by which sperm-cells and germ-cells are brought together for the propagation of the race.  We are now concerned with the necessary interplay of the differing male and female roles in courtship, and with their accidental emotional by-products.  Both male and female are instinctively seeking the same end of sexual union at the moment of highest excitement.  There cannot, therefore, be real conflict.[63] But there is the semblance of a conflict, an apparent clash of aim, an appearance of cruelty.  Moreover,—­and this is a significant moment in the process from our present point of view,—­when there are rivals for the possession of one female there is always a possibility of actual combat, so tending to introduce an element of real violence, of undisguised cruelty, which the male inflicts on his rival and which the female views with satisfaction and delight in the prowess of the successful claimant.  Here we are brought close to the zooelogical root of the connection between love and pain.[64]

In his admirable work on play in man Groos has fully discussed the plays of combat (Kampfspiele), which begin to develop even in childhood and assume full activity during adolescence; and he points out that, while the impulse to such play certainly has a wider biological significance, it still possesses a relationship to the sexual life and to the rivalries of animals in courtship which must not be forgotten.[65]

Nor is it only in play that the connection between love and combativity may still be traced.  With the epoch of the first sexual relationship, Marro points out, awakes the instinct of cruelty, which prompts the youth to acts which are sometimes in absolute contrast to his previous conduct, and leads him to be careless of the lives of others as well as of his own life.[66] Marro presents a diagram showing how crimes against the person in Italy rise rapidly from the age of 16 to 20 and reach a climax between 21 and 25.  In Paris, Gamier states, crimes of blood are six times more frequent in adolescents (aged 16 to 20) than in adults.  It is the same elsewhere.[67] This tendency to criminal violence during the age-period of courtship is a by-product of the sexual impulse, a kind of tertiary sexual character.