Ethology is the science of animal behaviour: why and how animals behave the way they do.

Pure ethology studies the behaviour of wild animals in their natural habitat. Applied ethology deals with animals out of their natural habitat, especially with behaviour modification, training, and abnormal behaviour, so it includes many welfare issues of domestic horses. Confusingly, the term behaviourism refers to the mechanisms of learning, often in the laboratory; it excludes emotional behaviour.

Natural selection during evolution acts not only on the genes that shape an animal´s body but also on those that influence its perceptions, reactions and innate urges, maximizing its chances surviving and reproducing in its natural way of life. These behavioural characteristics persist even in unnatural environments (as in domestic situations) since they are part of its genetic heritage.

Therefore, we´re dividing this section into: