Think Positive, Stress Less? Testing Mindset Against Stress Scores Students complete the Positive Mindset Index (PMI) measuring current-state happiness, confidence, and optimism, and the Perceived Stress Scale (PSS) measuring stress over the past month, then pool data to calculate a Pearson r. The lab includes an important methodological teaching moment: the PMI measures the present moment while the PSS covers the past month, creating a temporal mismatch students must consider when interpreti