This article describes psychological research on why tragedies of individuals and small numbers of people elicit more global emotional arousal than tragedies of large numbers of people.
"Jamal Khashoggi: Assassination, Abattoir, and the Law of Small Numbers,"
International Bulletin of Political Psychology: Vol. 18
, Article 6.
Available at: https://commons.erau.edu/ibpp/vol18/iss5/6