From restaurants to handbags to political candidates, authenticity is valued in many different contexts. Yet we lack a comprehensive way of understanding what authenticity means and why we seek it. This interdisciplinary essay, drawing on research from multiple fields such as marketing and sociology, proposes that while a unified definition of authenticity may be elusive, our motivations for seeking the authentic can be explained by a desire to learn information that reveals some valuable truth. Though the desire for authenticity is easily manipulated (often by commercial interests), I argue that it is not primarily a socially determined and superficial drive but guided by an adaptive desire for knowledge. I outline four related motives for valuing authentic entities, all connected to the search for valuable information. And I show how these motives can explain what authenticity means in the domains of art, food, culture, consumer goods, lifestyle and people.