A shallow or blunted affect does not imply the complete absence of emotions. This part of the psychopathic condition merely implies that the emotions felt by the psychopath are weaker and of shorter duration than that of the neurotypical. It does not follow that the psychopath does not feel anything at all.
Separating organic emotions caused by abnormal neurochemistry from spontaneous emotions experienced as the result of living life is key to understanding this. A psychopath can experience unipolar or bipolar depression as a result of organic issues within the brain. However, a psychopath can also feel depression or sadness, although on a much weaker level, due to a plan going awry or a favorite plaything being lost. Just because the emotion is weak does not mean that it does not deserve a name; it is still potentially present for the psychopath.
Another example would be that of elation or satisfaction. Many psychopaths find that they need ever-increasing levels of stimulation to make it through their lives. However each fix, in the moment, can yield some sense of satisfaction. It is just that this, like any other emotions for the psychopath, is of a weaker magnitude and a shorter duration than that of the neurotypical.
A key difference between those emotions for the psychopath and those for the neurotypical are that the psychopath’s emotions are what I would term ‘self-created’. There is no automatic joy or sadness due to others’ elation or despair as this would require affective empathy rather than cognitive empathy. In this absence, the psychopath’s emotions can only come from her own endeavors.
Shallow does not mean absent. Often enough, these emotions are all the psychopath has in relation to the experiences of the neurotypical. They should be held in high regard as part of the human experience rather than in a dismissive manner and the outsider must learn that some emotion is more than no emotion.