“Learn Something in One, Derive It in Two, It Falls into the System, and Changes What We Do”

A look at the human learning process

One of the most profound insights from Relational Frame Theory (RFT), the behavioral science foundation of Acceptance and Commitment Therapy (ACT), is captured in the phrase often used by Steven Hayes, Ph.D.: "We learn something in one, derive it in two, it falls into the system, and changes what we do." This concept underscores the incredible capacity of human cognition to generalize knowledge through symbolic language, applying it flexibly across contexts.

As clinicians, we witness this process unfold in therapy sessions, where seemingly small moments of learning ripple through the system, transforming behavior in ways that can ultimately free us—and our clients—from the limitations imposed by our own minds. It’s a powerful idea, rich with implications for clinical practice, deserving of deeper exploration and reflection. Let’s break this concept down and explore how it can inform and shape our clinical practice.

---

Step 1: Learn Something in One

This is the moment of direct learning—an individual comes into contact with a specific piece of information or experience. For example, a child learns that touching a hot stove results in pain. In RFT terms, this creates a simple stimulus-response relation: “Stove” → “Danger.”

In therapy, these direct relations often emerge when clients encounter new insights about their thoughts, feelings, or behaviors. For instance, a client might learn that avoiding conflict reduces immediate anxiety but increases long-term relational strain. While the learning starts here, it does not stay static.

---

Step 2: Derive It in Two