We know how connection—a loving gaze or gentle touch, for instance—looks and feels. And similarly, we know how a broken connection—averting that gaze or rescinding that touch—also looks and feels. But why do we connect and disconnect the way we do?

Psychologist and professor Stephen Porges, developer of the Polyvagal Theory, says our ability to form relationships is partially rooted in our biology, more specifically, the vagus nerve, which interfaces with our parasympathetic nervous system. And while our modern world offers us unprecedented opportunities to communicate with others, like social media and text messaging, many of us are finding ourselves feeling more stressed and less connected, productive, and fulfilled. But why?

In the video clip, Porges explains how trauma can affect our ability to truly connect, and how this is reflected in our bodies. He also shines a light on how our modern comforts may be hastening disconnection at an alarming rate.

Porges’ work dramatically broadens our understanding of the sympathetic and parasympathetic systems, and explains how our bodies and brains interact with one another to regulate our physiological states. But more relevant to therapists, our nervous systems also influence long-term issues with intimacy and trust. “Trauma disrupts our physiological state,” Porges says. “It distorts our social awareness and displaces social engagement with defensive reactions.”

Like other mammals, Porges says humans act a particular way when frightened. “They shift states to defend, become more reptilian, and lose access to their social communication skills,” he explains. “By understanding this adaptive reactive to danger, we’ve uncovered a neurobiological mechanism that enables us to better understand and treat mental disorders.”

Stephen Porges

Stephen Porges, PhD, is Distinguished University Scientist at Indiana University, where he’s creating a trauma research center within the Kinsey Institute. He’s author of The Polyvagal Theory.