Ethology is the scientific and objective study of animal behaviour, usually with a focus on behaviour under natural conditions.[1] Behaviourism is a term that also describes the scientific and objective study of animal behaviour, but it usually refers to the study of trained behavioural responses in a laboratory context.

Many naturalists have studied aspects of animal behaviour throughout history. The modern discipline of ethology is generally considered to have begun during the 1930s with the work of Dutch biologist Nikolaas Tinbergen and by Austrian biologists Konrad Lorenz and Karl von Frisch, joint winners of the 1973 Nobel Prize in Physiology or Medicine.[2] Ethology is a combination of laboratory and field science, with a strong relation to some other disciplines such as neuroanatomy, ecology, and evolution. Ethologists are typically interested in a behavioural process rather than in a particular animal group, and often study one type of behaviour, such as aggression, in a number of unrelated animals.

The desire to understand animals has made ethology a rapidly growing field. Since the turn of the 21st century, many aspects of animal communication, animal emotions, animal culture, learning, and even sexual conduct that experts long thought they understood, have been re-examined, and new conclusions reached. New fields have developed, such as neuroethology.

Understanding ethology or animal behaviour can be important in animal training. Considering the natural behaviours of different species or breeds enables the trainer to select the individuals best suited to perform the required task. It also enables the trainer to encourage the performance of naturally occurring behaviours and also the discontinuance of undesirable behaviours.