Healthy happiness: The effect of happiness in promoting brain health.

The Merriam-Webster dictionary defines happiness as "a state of well-being and contentment". Psychologically, happiness can be defined as a state of current well-being and positivity resulting from recent stimuli, as well as long-term life satisfaction and peace of mind. This refers to two aspects of happiness discussed in psychology, first coined by Aristotle, pleasurable happiness known as "hedonia" and the long-term happiness of living a good life called "eudaimonia". These early concepts break down the vaguer and complex idea of happiness into long-term pleasure and positivity. This is where it starts to get more challenging when we try to define happiness in neurobiological terms. Many regions, pathways and circuits in the brain work in tandem to create the conscious and recognized state of happiness we cognitively perceive as humans. However, happiness is a feeling that transcends species boundaries. It is a positive state of emotions that can be expressed in different ways, including contentedness, peace, pleasure, excitement, relief, joy, and more. To do this, happiness must be broken down into constituent parts, localized to specific neuroanatomical regions, and associated with specific projects and structures to really build the anatomical architecture of happiness. Understanding how emotion is quantified and experimentally studied allows the field of neuroscience to build a comprehensive "neurobiological happiness model". Here in this chapter, we discuss historical and novel findings into this emotion; we discuss its implication as an evolutionary advantage in the adaptive response, how laughter is associated with happiness, and how a state of positive well-being plays a role in promoting positive brain health.