Far from schematizing, reducing or splitting human beings with misleading dualistic, behaviorist or materialistic explanations, the new human ethology reveals the surprising and extraordinary complexity and plasticity of our development and behavior. It is not at all a matter of «extrapolating» animal behavior to human behavior and thus humanizing the animal to better animalize man, but of identifying, at the point of greatest similarity, those differences that make human beings a species distinct from others: among them, the acquisition of speech, a marvelous instrument that gives us a new degree of freedom from the immediate constraints imposed by the outside world. Likewise, in coordination with the practices of clinical psychiatry, human ethology has made possible important therapeutic advances in some of the most serious conditions that prevent little humans from accessing the adventure of speech: it has made understandable the delays in speech development caused by early affective deficiencies in abandoned and isolated children, it has investigated the use of signs by speechless humans (aphasics, autistics and feral children), it has made it possible to understand the structure of time in the elderly and Alzheimer's disease. It has also made it possible to help the thousands of «non-existent» children, the result of consummated incest, freeing them from their dramatic confinement in the silence of shame, and, in short, overturning many clichés and certainties and dismantling old prejudices about human beings and the other animal species that populate our world.