The Pygmalion effect notes that if one expects a person to improve, then they will often improve. This is similar to the Greek myth of Pygmalion, who enhanced his statue until it became alive.
The Golem effect notes that if one expects a person to deteriorate, then they will often deteriorate. This is similar to the Jewish myths about the Golem.
Both are self-fulfilling prophecies.
As a result, I decided that I will expect everybody and everything to improve, and I encourage everyone to do the same. It might or might not work, but should not hurt.
As a case study, most cars in my neighbourhood used to not stop for letting pedestrians cross. Then I started waving to thank those that did, like I saw being done at Scotland. Now most of them do stop. Positive feedback often does work.