Ivan Pavlov was a very renowned scientist who had his heart in researching and has his heart and also the researcher was studying the behaviour of dogs when he found another aspect during observation that the dog he was training. The aspects of behaviour can be manipulated with other factors. The reason for behaviour to occur is that one stimulus must have triggered that other behaviour. The other behaviour is the response for a stimulus that was presented. The contributions of both the scientists, Ivan Pavlov and John B. Watson, are commendable and indispensable in the behavioural field (Jarius, & Wildemann, 2017).