Loneliness is a basic risk factor for health. At the developmental level, the need for social connection precedes the birth of language (see pointing and shared attention); at the epidemiologic level, the so-called Roseto Effect indicates the close link between interpersonal cohesion and survival; at the affective neuroscience level, the construct of embodied cognition indicates the link between biological mechanisms, including hormonal and immune systems, and psychological and social systems. The construct of loneliness is usually referred to as implicit (assessed with non-verbal indicators) and explicit (assessed with self-report scales). Literature in the last 20 years has shown that loneliness, particularly implicit loneliness, is a powerful risk factor for morbidity and mortality, has an equal weight as the most common risk factors (obesity, smoking, exercise) and is related also to young adults.
Keywords: Affective neuroscience, Epidemiology, Loneliness, Risk factors, Embodied cognition, Health.