One definition was "passions are defined as high-priority goals with emotionally important outcomes" (Frijda et al. 1991 cited in Jowett and Lavelle 2007,p.250).Passion is not the same as commitment or motivation per se. They can overlap but the difference is the issue of internalisation.
The issue of internalisation means the activity defines us and is part of our identity (i.e. who am I and how I see myself). The activity is integrated into ourselves. You may be committed to learning piano or violin or bringing up someone else's step-child and be motivated to do this for the benefits of just doing that ... but it is not a problem if you stop in terms of emotional costs, as these are not self-defining activities. (You get the idea .. make up your own example here).
There are two types of Passion: Obsessive Passion vs Harmonious Passion.
The former has an aspect of compulsion to engage with the activity, as if the participant is controlled by the activity and there is emotional dependency. (I think the book was making a distinction between this and addiction, however).
The latter - harmonious passion, has an aspect of choice in it and the activity fits in with other commitments and does not disrupt them dysfunctionally.
As with many concepts in psychology, there is a scale to measure this ...'The Passion Scale' (Vallerand et al 2003, cited in ibid,p.254).
The Passion Scale
1, My activity allows me to live a variety of experiences
2. The new things that I discover within the confines of my activity allow me to appreciate it even more
3. My activity activity reflects the qualities I like about myself
4. My activity is in harmony with other actives in my life
5. My activity is a passion that I am still manage to control
6, My activity allows me to live memorable experiences
7. I am completely taken with my activity
8. I cannot live without my activity
9. The urge is so strong. I cannot help myself doing the activity
10, I have difficulty imagining my life without my activity
11. I am emotionally dependent on my activity
12 I have a tough time controlling my need to do my activity
13 I have an almost obsessive feeling to my activity
14 My mood depends on me being able to do my activity
Where are you on this scale?
Is this scale of use deciding who is worth spending energy on if you had to choose between prospective students, or prospective activities?
Is this scale useful in moderating commitments and preserving a participants life-cycle in the activity?
Is the scale valid? Can you measure 'passion' like it was temperature? Does it really exist as a 'thing' in reality?
(I have yet to study the whole chapter .. I may type up some more later). This should make us think however...