Question

Which relationship is a causal relationship?

social media posts and sleep times

study times and exam scores

outside temperature and ice cream sales

lifting weights and gaining muscle

Answer 1

Three of them are plausibly causal; one is only clearly correlational/ambiguous.

- Study times → exam scores — causal (more studying generally causes better scores, though quality of study and prior knowledge matter).
- Outside temperature → ice cream sales — causal (warmer weather increases demand for ice cream).
- Lifting weights → gaining muscle — causal (resistance training causes muscle hypertrophy, given adequate nutrition and recovery).

- Social media posts ↔ sleep times — ambiguous/correlational (late-night posting may delay sleep, poor sleep may increase posting, or a third factor like lifestyle or stress could cause both). To establish causation you’d need controlled or longitudinal evidence.