Ivan Pavlov
publication date: Sunday, August 17, 2025 (part of August 2025)
category: Science
clue: This Russian scientist figured out why you feel a sudden urge to play the goo game whenever you hear the clock strike 12am ET.
explanation: Pavlov discovered classical conditioning, which are psychological and physiological responses to external stimuli, such as a dog salivating when it hears a bell that it associates with being fed. more…
intended difficulty: very easy
solved by: Russ Wilhelm, Steve West, Samir Mehta, Richard Slominsky, and LaVonne Lemler
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