The factor that relates well to the conversation between the teacher and Hellyou is the Rosenthal Effect. This phenomenon occurs when higher expectations lead to an increase in performance. By complimenting the student and making her feel good about herself, the teacher is essentially setting a positive expectation that may enhance her self-esteem and foster better performance.
As for the second question regarding who demonstrates empathy effectively, while there are variations among individuals, research suggests that females generally tend to demonstrate empathy more effectively than males, owing to socialized behaviors. This isn't a strict rule, but it's a trend seen in many studies on gender and empathy.