In today’s world we continue observing declines in mental health worldwide while access to health care and treatment keeps decreasing (especially in low- to middle-income countries). Well-being and the brain mediate each other across the lifespan, and much is still unknown about their relationship. Electroencephalography (EEG) is the measure of electrical activity of the brain at the surface of the scalp. It is widely used to study human psychology, cognition, affect, and neuropathology. However, it is costly and time-consuming, leading to most studies consisting of small and undiversified samples. Recent technological advances have led to the development of affordable, light-weight, wearable, and wireless EEG systems. They offer fast preparation time, high mobility, and facilitate the collection of EEG data over large and diversified populations. In turn, these large and diverse datasets can help researchers identify trends, mediator covariables (e.g., age), and classify mental states.