This article—one of only two on the “top twenty” list published later than 1986—undertook two tasks. The first was to examine whether the “democratic peace” was a spurious relationship that could be disconfirmed by several possible alternative explanations. The second was to provide a stepping stone—to be revised and improved by others—for converting the democratic peace from a theoretically loose, substantially intuition-driven project into a research program in which theory and empirics reinforced each other.

Bernard Berelson wrote a memoir about Human Behavior: An Inventory of Scientific Findings, a book that brought together 1,003 findings about human behavior with some reasonable supporting evidence. Berelson offered a threefold grand summary of all social science research: (1) Some do, some don't. (2) The differences aren't very great. (3) It's more complicated than that.