> The most recent results, captured June 14-20, 2021, are based on 4,820 U.S. adults surveyed by web as a part of the Gallup Panel, a probability-based, non-opt-in panel of about 120,000 adults across all 50 states and the District of Columbia.

People surveyed online have higher life ratings.

Edit: to show that it’s always important to understand how data is collected.