This book reviews the current state of knowledge in the field of child and adolescent psychology. It distinguishes between what is new in child psychology, given that certain phenomena did not previously exist in a significant way in the lives of young people (such as homoparentality, attacks, cyber-bullying or Covid-19). It also examines new studies of subjects that already exist and have done so for a long time (intelligence, the mother-child relationship, etc.), but where significant theoretical developments have taken place in the contemporary period.