CORRELATION, CAUSATION & BELIEF SYSTEM

Steven and  Stasha are connecting three distinct epistemological ideas: observation, inference, and prior belief on The Diary of a CEO (July 27, 2026).

Steven says:

"And we're arriving at a conclusion based on some factors that we can see, which is often correlation and not necessarily causation."

He's describing a classic problem in medicine and science. We often notice that two things occur together—for example:

• People with low vitamin D have higher rates of depression.
• Coffee drinkers live longer.
• Patients taking a certain supplement recover more quickly.

Those are correlations. They tell us that variables move together, but they don't tell us why.

Possible explanations include:

• A causes B.
• B causes A.
• A third factor causes both.
• The association is partly or entirely due to chance or bias.

This is why medicine prizes randomized controlled trials: they are designed to isolate causation from mere association.

Steven is therefore making an epistemic point: what we observe is often weaker than what we conclude.

Then Stasha immediately responds:

"Correlation. Very important. We all have a belief system."

At first glance, "belief system" seems like a change of subject, but it's actually an extension of Steven's point.

She's acknowledging that, when evidence is incomplete, our interpretation of correlations is filtered through prior assumptions.

Imagine two physicians seeing the same study:

• One believes vitamin D deficiency is a major driver of disease.
• The other believes it is mostly a marker of poor overall health.

They read the same data but arrive at different conclusions because they begin with different conceptual frameworks.

This is exactly what philosophers of science—from Thomas Kuhn to Karl Popper—have argued in different ways: data never interpret themselves. Observation is always shaped, at least partly, by the theories and expectations we bring to it.

Interestingly, Stasha does not say:

"We all have biases."

She says:

"We all have a belief system."

That's a subtler claim.

A belief system isn't necessarily irrational. It's the network of assumptions, values, prior knowledge, and experience that helps us decide which explanations seem plausible.

A physician trained in infectious disease, an endocrinologist, and an epidemiologist may each weigh the same evidence differently because they inhabit somewhat different explanatory frameworks.

Taken together, the exchange could almost be paraphrased as:

Steven: "Be careful not to mistake association for cause."
Stasha: "And remember that what we infer from those associations is influenced by the conceptual framework we already possess."

That combination—statistical caution plus awareness of one's own interpretive framework—is one of the foundations of evidence-based medicine. It is also why good scientists are expected not only to collect data, but to continually question whether their own expectations are shaping the conclusions they draw.

P.S.
Correlation means two things are related.
Causation means one thing produces or changes the other.