Different positive effects of interactions with animals, such as reduction of stress reactions, depressive mood, anxiety, aggression, and pain, and promotion of trust, calmness, motivation, and concentration have been documented by research on human-animal interaction (HAI), including animal assisted interventions (AAIs). Potential biological, psychological, and social processes may underpin these effects. Theories of why this may occur include biophilia, anthropomorphism, a focus on the experiential system instead of the verbal-symbolic system, motivation, activation of the oxytocin system, attachment and caregiving including provision of social support for stress buffering, and distraction processes. Understanding how animals may positively affect educational and therapeutic settings, in particular for individuals with psychical and psychosocial challenges, and finding what special indications for AAI exist, and which preconditions of learning in the client or the setting could potentially be enhanced, might provide not only a better rationale for AAIs but also promote their efficacy.