Irrationality arises from pushing rational self-interest to extremes.

Evidence

Irrationality, Adorno contends, need not be regarded as adopting policies wholly disconnected from individual and collective ego aims. On the contrary, it is cases where rational self-interest as normally understood is pushed to extremes so as to become irrational, the historical fate of reason presented in Dialectic of Enlightenment, that are to be studied. The surface rationality of the common sense advice proffered by astrology columns corresponds to this premise. Such columns are far from esoteric in what they advise; for example, today is a good day to avoid family arguments, sort out one’s financial situation, buy, sell, plan a holiday, begin a relationship, beware of involvements, etc. — Theodor W. Adorno, The Culture Industry, 33

Categorization

• DEFINE: Methodological point: mass-culture irrationality is continuous with hyper-rational self-interest, not opposed to it — a falsifiable criteria for analysis.
• XREF: connects to: Modern avarice consists of stinginess toward others masked as rational self-interest; Rationality itself has become the most effective vehicle of mystification. — Herbert Marcuse, One-Dimensional Man: Studies in the…, 689; Society’s growth-propelling rationality is itself irrational despite apparent efficiency — Herbert Marcuse, One-Dimensional Man: Studies in the…, 92