My heart is so small
it's almost invisible.
How can You place
such big sorrows in it?
"Look," He answered,
"your eyes are even smaller,
yet they behold the world."
~ Rumi ~
The movie Return of the Jedi, the final part of the Star Wars series, includes a scene in which Luke Skywalker turns to Darth Vader and says, "I know there's still good in you. There's good in you, I can sense it". Is it possible that these simple words could have persuaded Vader to come over to the Light Side? If we look at social psychological research, the answer appears to be yes.
The strategy demonstrated in these words, known as the labeling technique, involves assigning a trait, attitude, belief or other label to a person, then making a request of that person that is consistent with the label.
In an effective demonstration of this strategy, two researchers, Alice Tybout and Richard Yelch, showed how the labeling technique could be used to increase the likelihood that people would vote on an election day. They interviewed a large number of potential voters and randomly told half of them that, based on their responses, they could be characterised as "above-average citizens likely to vote and participate in political events". The other half of the interviewees were informed that they could be characterised as "about average" in terms of these interests, beliefs and behaviours. Those respondents labeled as good citizens and having a high likelihood of voting not only came to see themselves as better citizens than those labeled as average, but were also 15 per cent more likely to vote in an election held a week later.
A useful approach, assuming that you still believe him to be capable of the task, would be to remind him how hard-working and persevering he is. You should even point out examples of previous times when he has triumphed over similar challenges and delivered successfully.
Teachers, trainers and parents can apply this labelling strategy to sculpt desired behaviours by pointing out to their audience that they regard them as just the type of person who would thrive when given this sort of challenge.