Comment by MrFantastic

I think it would be hard to imagine what a heavy lift feels like if you never done it. The pinky example might have helped just because it gave the test subjects an example of what muscle it works, firing the pinky and the ring finger at the same time would be a stronger pull because they share the flexor digitorum profundus. They also would have had to test it first to establish a baseline.

I think that one reason people have trouble with pullups is that they just don't understand how to tense up their entire body torso to pull themselves up.