System 2 deals with both questions from someone else (“Did you like the food?”) and from your own mind (“Do I really need to buy this?”). Both answers come from directing your attention and searching your memory. That is not how System 1 operates. It constantly monitors what is happening inside and outside our mind. It unintentionally and effortlessly assesses the elements of the situation. These ‘basic assessments’ affect our intuitive judgment, because they are easily replaced with harder questions. Two other characteristics of System 1 supporting the replacement of one judgment with another are the ability to translate values across dimensions (“If Chloe were as heavy as she is smart, how heavy would she be?”) and triggering other computations, like basic assessments.

An example of a ‘basic assessment’ is the ability to distinguish between an enemy and a friend in the blink of an eye. System 1 rapidly provides the judgment whether it is safe or not to interact with a stranger. In one glance at someone’s face, we can evaluate how trustworthy and dominant (thus threatening) that person is and whether we expect his/her intentions to be hostile or friendly. Dominance is assessed by looking at the shape of the face (square chin) and intentions are predicted through facial expressions. Face reading is not 100% reliable, a stranger with a round chin and a (fake) smile can still have bad intentions. In today’s society, this evolutionary ability is used to influence the voting behavior of people. Participants were shown campaign portraits of politicians and asked to rate their competence and likability based on their faces. The winner of the election turned out to be the person with the highest competence rating. Ratings of likability were less predictive of the voting result. Competence was judged by combining trustworthiness and strength. However, facial features are not predictive of how well someone will perform. Rejecting a candidate is based on the lack of attributes we consider important. Studies of the brain show that losing politicians evoked a greater negative emotional response, which is an example of a ‘judgment heuristic’.

The influence of System 1 on voting varies among people. Research shows that politically uninformed and television-prone voters are more likely to fall back on the automatic and quickly formed preferences of System 1. The effect of facial competence on their voting behavior is three times greater in comparison to informed voters who watch less television.

What is intensity matching?

Questions about one’s popularity, happiness or suitable punishments have one thing in common: they refer to an underlying dimension of amount or intensity. It is linked to using the word ‘more’ (more popular, more happy, more severe). This regards another ability of System 1: matching across various dimensions. An example is the following. “Richard read fluently when he was five years old. What is your prediction of his future GPA?” You will answer by translating from one scale to another scale and choose the matching GPA. Predicting by matching is a natural operation of System 1 and System 2 usually accepts it, but it is statistically wrong.

What does Kahneman mean with ‘mental shotgun’?

System 1 is constantly monitoring what is going on around you and unintentionally carries out multiple routine assessments at the same time. Other assessments are carried out only when needed. These judgments are voluntary: they occur by choice. Our control over intended judgments is not precise though, we usually assess much more than needed or wanted. This excess computation is called the ‘mental shotgun’. Similar to a shotgun causing scattering pellets when aiming at one specific target, it is impossible for System 1 not to do more than System 2 demands it to do.

Consider the following example. Participants had to listen to pairs of words and were asked to hit a button as soon as they noticed the words rhyming. The pairs both contain rhyming words:

BOAT – NOTE

NOTE – MOTE

The participants did not see the words, but they were also influenced by the difference in spelling. They took longer to detect the words rhyme if their spelling was different. The task was to only compare the pronunciation, but they also compared the spelling. The intention to answer one question induced a pointless second question. The combination of intensity matching and a mental shotgun explains having intuitive judgments.