“Pam Mueller and Daniel Oppenheimer, the psychologists who conducted the
new research, believe it’s because students on laptops usually just
mindlessly type everything a professor says. Those taking notes by hand,
though, have to actively listen and decide what’s important — because
they generally can’t write fast enough to get everything down — which
ultimately helps them learn.”
Link to the study: Mueller and Oppenheimer, “The Pen Is Mightier Than the Keyboard: Advantages of Longhand Over Laptop Note Taking,” Psychological Science 25:6 (June 2014), 1159-1168.