Mental Factor which Unites Other Factors

If I think of the *Noble Eightfold Path* for example, or even the *Abhidhamma* traditions, I feel mental factors are clearly *related,* but noted as separate. In sum, my question mainly is: **What conditions cause mental factors/qualities to aggregate, i.e. lead to the development of others, and what conditions cause them to remain separate? Is there a unique condition (e.g. a mental factor) that unites others in the mind?** In non-Buddhist sources, strong *pleasure* as in addiction seems to channel the mind towards doing but one thing, to exclude in a way causing shame. But positive emotions such as *joy* tend to broaden one's perspective and capacity of action. A researcher on this says : > But as the sun rises in the sky, things begin to change. Your blinders > around your face begin to open and your world quite literally expands. > You can see more. Your world is larger. > > Just as the warmth of sunlight opens flowers, the warmth of positivity > opens our minds and hearts. It changes our visual perspective at a > really basic level, along with our ability to see our common humanity > with others. **Can this be related to this question?** Thank you