Infrahumanization is a term introduced by Belgian psychologist Jacques-Philippe Leyens and colleagues in 2000, referring to a tendency for people to perceive individuals in other groups as being somewhat less human.

Source:

Leyens, J. Ph., Paladino, M. P., Rodriguez, R. T., Vaes, J., Demoulin, S., Rodriguez, A. P., & Gaunt, R. (2000). “The emotional side of prejudice : The attribution of secondary emotions to ingroups and outgroups”. Personality and Social Psychology Review 4 (2): 186–197.

See lectures on the subject of infrahumanization.