Which concept is cited as a plausible reason people act differently when the full moon is out?

• A. Confirmation bias
• B. The gravity explanation (a mosquito on your arm has more gravitational effect than the moon)
• C. Which quadrant are you most likely to notice the moon effect in
• D. The moon effect is a real, verifiable phenomenon

Answer: (A)

The idea being tested is how our own beliefs shape what we notice and remember. Confirmation bias leads people to seek out and interpret information in a way that confirms what they already think, so they’re more likely to notice or recall cases where behavior seems to change during a full moon and discount evidence that it doesn’t. In other words, the full moon becomes a lens through which ambiguous or ordinary behavior is read as lunar-influenced, even though scientific studies don’t show a reliable behavioral effect. The gravity explanation is not plausible because the Moon’s pull on a person is extremely small—far too weak to cause noticeable differences in behavior. The quadrant question isn’t a mechanism for why people think the moon affects behavior, and saying the moon effect is real and verifiable attributes a phenomenon without addressing why people perceive it that way. So confirmation bias best explains why the phenomenon is cited.