"Contests, prizes, pep talks, badges, points, canned thank you notes, and recognition events. Most of this comes down to using rewards to motivate people to continue certain behavior.
Some of these work for some people, some of the time. But most of them backfire, for most people, most of the time.
The zeroth step in boosting motivation is to stop doing things that demotivate people."
Eight Reasons Retrospectives Fail
"Choosing Actions the Team Doesnâ€™t Have Energy For... They may have tried before and failed, the task may be too difficult or time-consuming given the other work they have to do, or the work may be plain unpleasant. In any case, when the team doesnâ€™t have energy to work on an improvement, chances are pretty good it wonâ€™t get done. Go with the task the team has the energy to complete."