Laughter is generally believed to have a benefical effect on our health, presumably because it lowers our stress level by helping us let off steam and being an integral part of any healthy relationship. By natural extension, something that enhances well-being is linked to survival. From this perspective, it certainly is logical for a sense of humour to have evolved throughout the history of mankind.. . Animal behaviour is considered quite complex and even if animals did have a sense of humour, it would probably not be manifested in the same way as it is in humans. Many animals do play, however, and this is an important aspect of their development.