**6.1 Toward a clearer terminology**

Our review on happiness has gathered studies referring to various disciplines. One of the most striking facts is the lack of common theoretical constructs regarding what has been meant by "happiness" across research reports (including within disciplines). Spanning from basic emotion to *eudaimonia*, the "happiness" notion seems to be difficult to characterize and scientifically study.

The conceptual ambiguity identified is close to that already observed between emotion and mood [134–135], as if the effective processes were difficult to refer through a unified approach. We propose that this state of affairs is related to i) the similar nature of affective processes that are associated with (positive or negative) valence evaluation whatever the level of processing and ii) the lack of integration of affective processes throughout the spectrum of bottom-up and top-down processing. In the following lines, we consider how this integration could be facilitated and we envisage a few regulatory processes of happiness.

## **6.2 Time and inertia: an affective momentum?**

The different sections of this review have illustrated two main principles. First, bottom-up and top-down processing can be thought of as different levels of processing and/or different information processing pathways. Second, both levels and pathways are required to understand how happiness is enacted. Bottom-up processing creates the "inputs" for subjective well-being (both at "affective" and "cognitive"<sup>2</sup> levels) as well as for *eudaimonia* or "psychological well-being."3 Complementarily, top-down processes create a mindset to guide attention, interpret incoming information, reappraise the situation, and compare the state of affairs with expectations. Each level of processing and each pathway is supported by corresponding biological structures (among which PFC represents a highly integrative hub).

We suggest that time, cognitive inertia, and increasing resonance all feature the processes that transform several initial affective events into the materials of, and conditions for, happiness. In our opinion, differentiating emotion, mood and happiness cannot be adequately realized without taking into account time dimension. Emotion, mood, and happiness (the latter here considered as *eudaimonia*) would consist in increasingly abstract and long cycles of subjective experience made of some form of summing of experience cycles pertaining to a lower level (*e.g*., several cycles of emotions for mood, several cycles of mood for happiness). This "resonance" principle (see also [136]) could be the basis for bottom-up moderation of *eudaimonia*. Iterative microcycles of effective experience could be integrated, generating an affective "momentum," the basis for subjective well-being, and the content for interpretative cognition leading to *eudaimonia*. This bottom-up route is coordinated with the top-down one. Each step of resonance at a higher level of integration (*e.g.*, from mood to *eudaimonia*) could involve top-down structuration of information, such that apart from the initial affective content that is taken into account, the abstraction process

<sup>2</sup> Note that we use here the prevalent terminology, though in our view, there is cognition in effective processing and effects in cognition.

<sup>3</sup> In the same vein, psychological well-being dissociated from subjective well-being may logically be questioned. This discussion, however, falls out of the scope of this chapter.

of affective experience is dependent on attentional deployment (large or focused), comparison (or not) with previous expectations (etc.). The two "access doors" to happiness are then related to personal events and associated affective experience on the one hand, and to the ability to organize a nurturing mindset on the other hand.
