Introduction: When Effects Distort Our Understanding of Causes In 1946, statistician Joseph Berkson noticed something peculiar in hospital patient data: diseases that should have been independent appeared to be negatively correlated. Cancer patients seemed less likely to have diabetes, and vice versa. This observation seemed to contradict everything known about disease independence. The answer to this paradox would eventually reveal one of the most counterintuitive principles in causal reasoning—the collider effect. A collider is a variable that sits at the convergence point of two or more independent causal pathways. The structure looks deceptively simple:Variable X → Collider Z ← Variable Y Two independent causes (X and Y) flow into a common effect (Z). But here’s the paradox: when we condition on the collider—when we only…

Revisiting Rule 1: Independent Variables Are Not Correlated Restating the Argument In Ashtanga Yoga, not all elements of practice are causally connected. For example, focusing solely on aesthetic performance (e.g., how a posture looks) often leads to false assumptions about progress. Understanding this independence helps practitioners avoid wasting energy on irrelevant or misleading correlations. Detachment (vairagya) serves as a guiding principle for staying grounded in what truly matters. Counterpoints, Holes, and Second Opinions 1. Do Variables Ever Exist in True Independence in Yoga? Counterpoint: Yoga philosophy emphasizes the interconnectedness of all things. The idea that two variables (e.g., strength and flexibility) are completely independent may clash with this holistic worldview. Can independence ever truly exist in a system as integrated as the body-mind connection? Alternative View: Instead…

In systems thinking and yoga alike, progress requires recognizing hidden confounders and addressing them directly rather than being misled by surface-level correlations. When practitioners address the root cause, both seemingly related symptoms often resolve harmoniously. Rule 1: Independent Variables Are Not Correlated This rule states that if two variables are causally independent, there will be no observable association between them in the data. For instance, if Variable A does not influence Variable B, their correlation will be zero unless influenced by an external factor. Intersection with Ashtanga Yoga: In Ashtanga Yoga, this can be explored through the principle of detachment (vairagya). The yogic system acknowledges that not all elements in life are interconnected in meaningful ways, and discernment (viveka) is required to understand what truly impacts…

The eight basic rules for causal inference from Peder M. Isager’s blog provide an excellent framework for understanding how causal relationships emerge and interact with observable data. These rules resonate with core principles in both systems thinking and Ashtanga Yoga. Let’s explore this connection. 1. Independent Variables are Not Correlated In systems thinking, an independent variable can be seen as an external input or a system component that does not directly influence other parts. This rule aligns with the yogic principle of detachment (Vairagya) where actions devoid of expectations (causal independence) do not entangle one in their outcomes. 2. Causal Influence Creates Correlation This mirrors the idea in systems thinking that feedback loops (positive or negative) generate observable patterns. In yoga, cause-effect chains are understood…

In systems thinking, a collider is a variable influenced by two or more independent factors—and Ashtanga’s authorization system contains a perfect example that explains why the current model is so resistant to change. Consider the collider: “Becoming an Authorized Teacher” This outcome is influenced by two largely independent variables: In an ideal system, both would be required for authorization. But the current Ashtanga authorization process primarily conditions on X (asana achievement), creating what statisticians call collider bias—a systematic distortion that produces misleading correlations. Here’s how the collider creates dysfunction: The Selection Bias When we only examine people who’ve achieved authorization (conditioning on the collider), we’re looking at a pre-filtered population. Within this group, we might observe that teachers with exceptional asana ability sometimes struggle with…