As a social psychologist addressing mainly the topics of social facilitation (motivation) and attitudinal effects of mere exposure (affect), between 1965 and 1975 Robert B. Zajonc authored prominent works that relied on or led to observations of the actions of nonhuman animals. Zajonc pointed to insects, worms, fish, fowl, birds, mice, rats, cats, dogs, monkeys, and apes as animal models whereby responses of beasts were used as evidential substitutes (with apparently equal weight) for responses of man. These efforts notwithstanding, animal-based research no longer has visibility in mainstream social psychology. Reasons for this absence include general historical trends in the field’s development.