two-system basis. One system is fast, intuitive, reactionary—a kind of constant fight-or-flight vigilance of the mind. It doesn’t require much conscious thought or effort and functions as a sort of status quo auto pilot. The other is slower, more deliberative, more thorough, more logical—but also much more cognitively costly. It likes to sit things out as long as it can and doesn’t step in unless it thinks it absolutely necessary.

