Co-authored with Sarah Bergenfield
Anyone who has ever trained for an event knows the dedication and resolve required. We add mileage, weight, reps, or minutes, a little at a time, in the hope that our bodies will become stronger and more accustomed to what we are asking of them. Neuroscientist Andrew Huberman reminds us that “we don’t train for events, we train for circumstances.” Training for a marathon doesn’t prepare the body for race day itself. It prepares the body for the conditions of long-distance running: sustained effort, discomfort, fatigue, unpredictability, and the need to keep going even when the finish line isn’t in sight. Muscles strengthen, mitochondria multiply, connective tissue adapts, and the cardiovascular system becomes more efficient, not because the body has rehearsed the exact event, but because it has learned what conditions to expect. Over time, the body builds a tolerance for those conditions, and the window of what it can handle begins to expand, because the brain learns to predict the conditions it expects to encounter.
The Predictive Brain
Rather than preparing for specific outcomes, the brain continuously generates predictions about what is likely to happen next, based on past experience. These predictions prepare the body in advance and are constantly checked against incoming sensory information. When prediction and sensory data align, we remain in a state of coherence. Nothing urgent needs to happen. But when there is a mismatch, when something in the present does not fit the brain’s expectations, a prediction error signal is generated, flagging uncertainty. At that point, the brain has several options: it can treat the mismatch as noise and ignore it, update its predictive model to better fit current conditions, or act on the world to make reality conform to expectation.
The brain evolved to minimize uncertainty because uncertainty is metabolically expensive. Preparing for too many possibilities at once requires more energy, more vigilance, and more physiological effort. At the same time, a completely predictable world offers little opportunity to learn or adapt. The nervous system functions best within a narrow range – enough uncertainty to stimulate learning and flexibility, but not so much that the system shifts into protection and overwhelm.
A full account of these processes is beyond the scope of this article, but the core idea is simple: the brain is constantly generating and revising predictions in response to experience. These expectations are shaped not by isolated events, but by repeated conditions, what reliably follows what, and how those conditions feel in the body.
Internal Family Systems and The Predictive Brain
IFS holds that the mind is plural, made up of subpersonalities, or parts, alongside a wise Self – a core consciousness rich in resources. Parts function from learned expectations, organizing the system around what experience has taught them to anticipate. They do not simply hold beliefs; they prepare the system for what they expect will happen next.
Over time, repeated experiences consolidate into patterns the system comes to rely on. Many of these patterns form early in life, when our agency is limited and our options few. As children, we learn not just what happened, but what it felt like to be in certain states; overwhelmed, ignored, unsafe, unseen. The brain encoded these conditions as meaningful patterns and learned to prepare for them in advance.
Our parts emerge within this context, organizing attention, emotion, and physiology around anticipated conditions, often before we consciously register what is happening. When a familiar pattern appears – raised voices, unpredictability, sensory overload, emotional distance – the body registers a shift: a churning stomach, an elevated heart rate. Protective parts interpret these signals through models shaped in the past and generate predictions about what is required: brace, withdraw, appease, control, shut down.
In effect, they are using an old map to make sense of current conditions, checking it against incoming sensory data and acting quickly to reduce uncertainty. These responses reflect the system doing exactly what it learned to do when options were limited. Only afterward do thoughts arise, attempting to explain or manage what is already underway. What we come to think is shaped by what the system has already prepared for.
IFS allows us to update our emotional predictive models. But, like physical training, change depends on repetition. Just as marathon training prepares the body for the conditions of long-distance running (repetition, fatigue, discomfort) working with our parts prepares the system for the conditions of everyday life. Running once a week doesn’t meaningfully change endurance; it simply reacquaints the body with effort. In the same way, checking in with parts during therapy brings awareness, but isn’t enough to reshape the system’s expectations.
Daily attention to your parts functions like emotional cross-training. Each time you pause to notice a part and respond to it with curiosity rather than urgency, you are doing the psychological equivalent of a training run. Crucially, this happens outside of crisis. By engaging your parts when nothing urgent is happening, you give them new information: the present is different from the past, and they do not need to prepare in the same way. These repeated, low-stakes interactions reshape the system’s predictions about what lies ahead and what it can tolerate. Over time, the nervous system learns that activation does not necessarily signal danger, and chronic activation begins to settle. As this happens, familiar cues are felt differently in the body. Feelings can move rather than be managed, and the thoughts that follow can shift.
We do not change our thinking by trying to think differently but by retraining the processes that generate thought in the first place. In the lexicon of IFS, our Self can see the world through the eyes of any given part, and our parts, in turn, can see the world through the transformative eyes of our Self, omitting neither danger nor beauty.