On the face of it, emotions in computers sound absurd. On the other hand, it would be tremendously worthwhile to have a computer that is congenial to interact with, flexible in its approach to doing what you want, makes snappy and intelligent decisions, and offers creative solutions to problems. It may surprise you to know that emotion plays a key role in all these qualities. The inability of today's computers to recognize, express, and have emotions severely limits their ability to act intelligently and interact naturally with us. But emotion without balance can also lead to disaster, as it does in 2001.
Emotion is a slippery word to define.
The fact is that even emotion researchers don't agree on a definition of emotion, and many of them don't consider such feelings as love to be basic emotions. They also argue about whether there are any basic emotions, or whether, instead, there are only continuous states or just different kinds of thoughts that we label emotions. It may be a long time before researchers come up with a commonly accepted definition of emotion. Nonetheless, the terminology can be confusing. On the other hand, we often use the words affect and emotion as, essentially, synonyms.