Measurable and true across industries, we what strain does on the mind. Judges grant fewer paroles as the day goes on — not because later cases are weaker, but because deciding case after case wears down their ability to deliberate. Doctors prescribe unnecessary antibiotics later in their shifts — not because their training changes by 3 pm, but because it is easier to write the prescription than to explain why it is not needed. Financial analysts also become less accurate with each forecast they make in a day.