to cut off his nose to spite his face

[dead flower]

Уважаемые переводчики! Помогите, пожалуйста, с этой фразой, смысл вообще не понимаю, во всех словарях порылать, не нашла такого выражения
конекст такой:

in encouraging such an attitude to satisfactory work in students, the teacher is essentially cutting off his nose to spite his face: he is teaching the childere to be superficial and unserious.

(главная мысль всего текста - на надо заставлять детей учиться только на 5)

Заранее всем спасибо!

[Translucid Mushroom]

http://en.wikipedia.org/wiki/Cutting_off_the_nose_to_spite_the_face

[donkey_hot]

Definition: create more problems by trying to eliminate another problem

Explanation: Used when speaking about the inadequacy of a certain solution to a problem.

Examples: If you do that you'll be cutting off your nose to spite your face. - He's cutting his nose to spite his face by working two jobs. He needs to spend less.

[dead flower]

Спасибо огромное!
Вы мне очень помогли!