The articles collected in this special section of «Popolazione e Storia» take stock of the results of previous inquiries in order to explore more in depth new research directions. The first two articles focus on the main promoters of the establishment of the Italian Committee for Eugenic Studies in 1913, an event reconstructed in detail by Luca Tedesco in this volume. Both Giuseppe Sergi (1841-1936) and Alfredo Niceforo (1876-1960), here studied by Angelo Caglioti, were influenced by Cesare Lombroso and his views concerning the necessity to prevent degeneration by monitoring and managing the population. The practice of the statistical measurement of the characteristics attributed to heredity was also crucial to a large part of Italian euge...