Why AI may overcomplicate answers: Humans and LLMs show ‘addition bias,’ often choosing extra steps over subtraction

When making decisions and judgments, humans can fall into common “traps,” known as cognitive biases. A cognitive bias is essentially the tendency to process information in a specific way or follow a systematic pattern. One widely documented cognitive bias is the so-called addition bias, the tendency of people to prefer solving problems by adding elements as opposed to removing them, even if subtraction would be simpler and more efficient. One example of this is adding more paragraphs or explanations to improve an essay or report, even if removing unnecessary sections would be more effective.