Comparative psychology is the scientific field that studies the mental processes and behavior of non-human animals. It also studies the phylogenetic history, adaptive significance and development of behavior. It uses many techniques to observe and understand the behavior of different species of animals such as dogs, pigeons, primates and dolphins. The main objective of comparative psychology is to establish principles of generality that focus on both proximate and ultimate causation. Research in this domain is closely related to the field of animal cognition, which studies attention, concept formation, memory, spatial cognition and time estimation in animals