“Searching for Animal Sentience: A Systematic Review of the Scientific Literature”

The emotional lives of non-human animals are often doubted and questioned. Due to the subjective nature of animal emotions, many think that they are out of the reach of scientific measurement. In this systematic review of over two decades of scientific literature, Proctor et al. found that this was not actually the case. By using a list of keywords, formed of both positive and negative emotions, and terminology relating to animal sentience, the researchers reviewed the scientific literature. They found that the subjective lives of animals are not only a vital part of human medical research but are regularly measured and studied with scientific rigor.