Rasas, human emotions, can affect and be affected by the four outer koshas. However, the self, is never affected by the rasas. The Sanskrit word rasa has many meanings, including emotion, mood and feeling. Tradition defines nine basic rasas: joy (hasya), fear (bhayanaka), anger (raudra), love (shringar), courage (vira), sadness (karuna), amazement (adbhuta), disgust (vibhatsya) and calmness (shanti). All people experience these emotions.

At an early age, babies smile and laugh when they feel joy. After six months, when mind and ego have unfolded, fear arises. Children who feel insecure may also get angry. At the onset of puberty, the rasa of love begins; it is the predominant rasa of teenagers. During puberty, we want to be a hero. In adolescence we may feel sadness if the prince (or princess) of our dreams still has not come. Rasas affect both our body chemistry and our mind. Our body chemistry changes, based on the emotion that is perceived by our mind. For example, fear causes our body to respond with emergency adrenaline. Fear also changes the smell of our bodies and the expression on our faces.

We find the nine rasas in literature, theater and dance. Dancers use their entire bodies to enact various rasas. Musicians strive to generate the right mood to uplift, calm, excite or sadden the audience. Writers and poets play with the rasas in stories about romance, tragedy and extraordinary matters. We leave the theater smiling or gloomy according to the main rasa of the drama. Just as life without rasas is incomplete, literature or film without rasas in proper proportion is deficient.