I don't know what "normal" means, anyway.
The German literary scientist Jürgen Link developed the concept of "normalism". According to Link, the mass collection and processing of data (using questionnaires, mathematical-statistical theories of distribution) produce normalities. These normalities are based on average statistical distributions following the ideal of the Gaussian distribution: one "normal" range in the middle that is average and two "anormal" extreme zones on each side of it (i.e. one above and one below average).
Link concludes that normalism "provides a simple, and apparently effective, set of tools for the regulation of in- and exclusion" as all attitudes, actions, roles and individuals within the normal boundaries are included whereas those outside the boundaries are excluded. He continues: "What seems so simple upon first glance turns out to be more difficult" as "no mathematical criterion exists which establishes the boundaries of normality" since the transition between normality and anormality is continuous. Interestingly, the normality boundaries can be tightened and as the normal range narrows, the anormal ones expand. The concept of normality is flexible, and with it, the concept of anormality.
Link, J. (2003) Concerning Two Normalistic Strategies: Regulating Inclusion and Exclusion, in: Normalising Diversity, based on a Workshop held on 2-3 June 2002, EUI Working Paper HEC, No. 2003/5, European University Institute, Florence, 9-22 (via), photo via