January 2026
The Physiology of Restraint: Stress in the Overcontrolled Nervous System
While it’s true that zebras don’t get ulcers – they can certainly teach us something about stress. Our bodies, all bodies, create stress hormones that impact the way the brain interprets an event. Most of Sapolsky’s chapters focus on the physical body (mammalian or reptilian), yet there is a directly proportionate relationship between the brain/body’s experience of stress or trauma and the emotional cost of stress. Chapters 8-14 explore everything from immunity to depression; the vital chapter for Between Sessions is 15. This segment focuses on personality, temperament, and their repercussions.
Chapter 15 identifies the presence of a different stress response belonging to repressive personalities – the disciplined, good-postured, and rule-bound. Sound like any clients you know? Highly socially conforming, discomforted when faced with ambiguity, and lack of “grey tones.” These clients are well-regulated on the surface and have tight sleep schedules. Sapolsky calls these personality types “repressors;” and they can be some of our toughest clients. It isn’t because they are over-reactive, what we typically see in psychiatric wards or whist creating safety plans. These clients are what RO-DBT calls the “OC clients” or “over controlled” individuals. There is a high physical, metabolic price.
OC clients are marked by overactive stress responses. High levels of glucocorticoids that are just as highly elevated as with depressed clients. So, how do they do it and how does it feel? Well, it’s simple and it’s not; you might even notice it in session. Outside elevated heart rate, muscle tension, and increased perspiration, their immune system becomes compromised. How many over-controlled clients do you have that are immune-suppressed or have autoimmune diseases? When a health care worker investigates with curiosity, they will find a desire and need for “social conformity, dread of social disapproval, and discomfort with ambiguity.” In their minds, there is no such thing as grey.
Sapolsky doesn’t dive too much into how to help these individuals, but the message is clear: it “can be enormously stressful to construct a world without stressors.” I find myself wishing for more constructive insight instead of an outline of “this is happening in your body when you’re stressed.” Lazarus & Folkman, forerunners of the Transactional Model of Stress and Coping introduced research akin to Sapolsky’s in 1984. Kobasa’s Hardiness Theory became more prominent in 1992. There is also a syndrome called General Adaptation Syndrome focusing on the body’s long-term stress response. Hans Selye published his research in June 1950. All this to say is there is a chance Why Zebras Don’t Get Ulcers is able to be understood; however, it’s certainly not news.
Discussion Questions:
1. Before reading this, how did you think about stress—as primarily emotional, physical, or both?
2. Sapolsky describes “repressive personalities” as highly disciplined, socially conforming, and uncomfortable with ambiguity. What strengths might come with this personality style?
3. What do you make of the idea that constructing a life designed to avoid stress can itself become stressful?
4. How might chronic muscle tension, sleep rigidity, or immune suppression be connected to emotional restraint?
5. What might it look like to gently experiment with flexibility rather than rigid control?
6. How has learning about the biological cost of stress changed your understanding of emotional restraint?
