Which movement did Francis Galton vigorously encourage to improve the population genetically?

Francis Galton was a prominent figure in the development of the eugenics movement, which advocated for the improvement of the human population through selective breeding. Galton, who was a cousin of Charles Darwin, believed that desirable traits can be inherited and that the quality of human beings could be enhanced by encouraging people with favorable genetic qualities to reproduce while discouraging those with undesirable characteristics from doing so.

Eugenics gained traction in the late 19th and early 20th centuries, promoting the idea that societal improvement could be achieved through controlled reproduction. Galton's work laid the scientific groundwork for this movement, as he introduced concepts related to heredity and genetics that later influenced eugenics policies.

In the context of the other options, humanitarianism is focused on promoting human welfare and social reform, which does not align with the selective and often ethically questionable principles of eugenics. Sociology studies social behavior and institutions, and while it can intersect with discussions about population and society, it is not about genetic improvement. Psychiatric epidemiology is a field that examines the distribution and determinants of mental disorders, but it does not address genetic enhancement at a population level.

Thus, eugenics is the movement that Galton vigorously encouraged, aimed at improving the