The book is the fruit of an impressive research lasting several years during which Alberoni has, for the first time in the world, studied the phenomenon of falling in love in children, pre-adolescents, adolescents and the transition to adult falling in love. Children do in fact fall in love, and at a very early stage. The greatest probablity we have of falling in love is when we enter a new social environment. Thus a child may fall in love when s/he enters nursery school ( at the age of three) or on beginning elementary school at the age of six. Falling in love in childhood, as in adult life, may come like a bolt out of the blue. It consists of palpitations, blushes, and desire for the other, but it differs from adult falling in love in that there is no sexuality, and children, not being independent, cannot form a couple in opposition to their parents. But the love bond is often tenacious, and may last a long time. At about the age of seven or eight children start to understand that their feelings are not always reciprocated. As a result the danger of refusal is warded off by means of shyness. Childhood love is often love at a distance, platonic love. In order to protect their delicate feelings from the brutal interference of adults, children resort to secretiveness and retaliate with embarrassment.

Friendship also begins at an early age, but is competely different from falling in love. It grows little by little and is consolidated through trust, respecting secrets. Our best friend is our confidant, the person we can tell our love problems to, sure that s/he will not reveal them. Children jealously protect their intimacy, and friends are its custodians. All our research shows that friendship is a moral feeling and its structrure remains identical from intimacy to old age.

About the age of eleven , with entrance to the middle school, children move into young society, what Alberoni calls youth international, since it is similar throughout the western world. They immediately assimilate its music, models, values and stars. At this point they reject the world of childhood, belittle their previous loves, and fall in love again. Girls begin to set their sights on older boys, and may fall madly in love with stars, especially singers.

The fourteen-to-sixteen age bracket for girls and fifteen-to-eighteen for boys make up the period of teenage falling in love, which is often an intense and brief experience. It is intense because teenagers are more autonomous, they can play their own game and are able to oppose the adult world. It is brief because they are in search of their own identity, trying to assert themselves and unwilling to be moulded by others. So the fusion process in falling in love is often rudely interrupted. Besides, also at the same age, adolescents are in search of what will become their adult personality. They carry out explorations, assuming first one role and then another. In this way they develop incomplete personalities from which their definitive adult one will emerge. Each incomplete personality leads them to fall in love with a certain type of partner, who is then abandoned when they try out another one. At this age girls tend to fall in love with older boys, so boys of the same age often meet with bitter disappointments. For males this encourages a separation between sexuality and love.

About the age of eighteen to twenty the construction of one's own adult self reaches a more advanced stage, so that the fusion between love and mutual adaptation becomes easier and love can become more stable.