Factoid: This 20 percent minimum reflects the research of social scientists studying innovation and diffusion, who have found that this is the critical number of members in any group which must endorse a new idea before the majority will accept it.
Source: (Win Arn, “How to Use Ratios to Effect Church Growth”, in Wagner, C. Peter, ed. Church Growth: State of the Art. Wheaton, IL: Tyndale, 1986, ch. 8, p. 103.)