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38. The 1960s tranquilizer Serentil: Elliott,
Better Than Well, xv.
39. Extroversion is in our DNA: Kenneth R.
Olson, “Why Do Geographic Differences Exist
in the Worldwide Distribution of Extraversion
and Openness to Experience? The
History of Human Emigration as an Explanation,”
Individual Differences Research 5, no.
4 (2007): 275–88. See also Chuansheng
Chen, “Population Migration and the Variation
of Dopamine D4 Receptor (DRD4) Allele
Frequencies Around the Globe,” Evolution
and Human Behavior 20 (1999):
309–24.
40. the Romans, for whom the worst possible
punishment: Mihalyi Csikszentmihalyi,
Flow: The Psychology of Optimal Experience
(New York: Harper Perennial, 1990),
165.
41. Even the Christianity of early American
religious revivals: Long before that silver-