Behaviour science played an important role in the interpretation of animals’ affective experiences, receiving compelling support from parallel studies in affective neuroscience. An important aspect of our understanding of animal welfare is that affective states can be negative or positive. Enabling animals to perform specific behaviours at key times when they are needed is central to the achievement of positive affective states. Another important event has been the development of practical ways to shift the spectrum of affective states towards a positive balance and their incorporation into welfare codes and regulations. The recent focus on positive affective states does not mean that negative experiences should be given less attention. In fact, in those countries that are at the early stages of the journey, improving function and productivity may be the most effective way to promote some important aspects of animal welfare. For example, alleviating pain is a useful entry point. Finally, it is important that the pace of the journey, in terms of public awareness and shifts in understanding, be supported by high-quality science that is rigorously assessed and validated in its practical application to the management of animal welfare.