Heuristics
Mental shortcuts that are automatic, intuitive and do not require conscious thought. They were initially described by Kahneman and Tversky in 1974.
References:
Tversky, A., Kahneman, D., 1974. Judgment under uncertainty: Heuristics and biases. Science. 185 (4157), 1124–31. doi:10.1126/science.185.4157.1124 (link)