For cause and effect to be demonstrated, what must occur?

For cause and effect to be demonstrated, it is essential that the cause occurs before the effect. This is a fundamental requirement in establishing a causal relationship. The temporal sequence ensures that the change in the dependent variable (the effect) can be attributed to the manipulation or presence of the independent variable (the cause), rather than the opposite or a coincidental relationship.

Understanding this principle is crucial in experimental research because it allows researchers to detect and validate the influence of one variable over another. If the effect occurs before the cause, then it cannot be established that the cause led to that effect, thereby undermining the validity of the causal inference being made.

While identifying a plausible mechanism or controlling for extraneous variables can strengthen the validity of a causal claim, the cornerstone of causation in experimental design remains the order of occurrence: the cause must precede the effect.