Peirce’s anti-psychologism hinges on two main assumptions. First, logic and psychology belong to two separate disciplines – respectively, the normative sciences and the experimental sciences. Second, externalism must be understood as a crucial and inescapable epistemological criterion. The introspectionist illusion, according to which individuals have direct and epistemologically flawless access to their own internal states, should be dismissed. As Colapietro (2003) and Calcaterra (2006) observe, Peirce’s standpoint is far different from the Kantian classical account of anti-psychologism. This original take on (...) anti-psychologism leaves room for a functional distinction between logic and psychology, emerging from a semiotic and communicative continuity. This means that psychology, unlike logic as a formal doctrine of signs, will be epistemologically appropriate for dealing with internal psychological states, on the condition that this inquiry be focused on the communicative processes through which these internal states are expressed and conveyed. Such a Peircean account of anti-psychologism forms the epistemological background of this paper. My goal is to show how Peirce’s approach to communication and semiosis can be applied in order to discuss a specific psychological theory, in this case, attachment theory. Specifically, I propose employing Giovanni Maddalena’s Peircean distinction between complete and incomplete gestures (Maddalena 2015) to account for the distinction between secure, dismissing and preoccupied attachment patterns. To this end, I will be discussing three different measurements of attachment: the Adult Attachment Interview (AAI, George, Kaplan & Main 1985), the Adult Attachment Projection (AAP, George & West 2006), and the Patient Attachment Coding System (PACS, Talia, Miller-Bottome & Daniel 2015). Throughout this discussion, I will examine the connection between the semiotic and phenomenological category of completeness, and the psychological category of security. This connection involves an interesting normative import, which I briefly discuss in the conclusions. (shrink)