Deliberate analytical thinking cannot run multiple tasks in parallel.

Evidence

System 2: must be consciously activated, works slowly, costs energy, is based on logic and conscious thought processes, but is not immune to mistakes. This system becomes active, for example, when we are solving a crossword puzzle, trying to match a face that seems familiar, choosing the new sofa for the living room, waiting for the traffic light to turn green, picking the most beautiful apple from the bowl. These thinking tasks require much more energy and concentration; you cannot do several of these System 2 tasks in parallel. — Holm Gero Hümmler, Ulrike Schiesser, Fact and Prejudice, 151

Categorization

• DEFINE: Explains Kahneman’s System 2 and its serial-costly nature.