It doesn&#x27;t have to be biological evolution or take thousands of years.  Most exploitation of irrationality works by playing off subconscious desires; once that leads to a very public and consequential failure, it is very quickly brought into consciousness, where future instances can be dealt with rationally.<p>Someone who invested their life savings in dot-coms in 1999 is probably never again going to invest in &quot;the next big thing&quot;.  That brings its own form of irrationality - once everyone believes that it&#x27;s foolish to invest in the next big thing, the next big thing becomes very underpriced - but they are at least not going to make the same mistake twice.