The Hawthorne effect is a situation in which effort or performance increases due to additional attention. According to the above definition, Which of the following situations belong to the Hawthorne effect:. ['The president of an electrical company often "if you want, you can" to motivate the scientific research team to complete the idea.', 'Xiao Wang, a junior high school student, declined his academic performance due to his addiction to games. The teacher severely criticized him. He was ashamed.', 'A company manager often emails new recruits to encourage employees to work hard.', 'Math teachers often praised several students for their intelligence.']