yes you can, you tell them that they cant acheive their goals, that it is unrealistic. phycoanalyse them in every possibly aspect. crush their will to live. maybe then they will stop being such arrogant pricks. i hate people who think because they do good in school they are "Better" than other people. maybe just because they bust a gut studying 6 hours a night after they get home from school is the reason they get good marks? maybe they arent as smart as the people who hold down a job, look after their siblings and put up with other stresses aswell as exceling at other hobies such as sport and still manage almost as good marks are better.
it was kind of funny at school the other day, one girl seemed intimidated because my friend beat her by 1/2 a mark when school is her entire life. kinda sad really when your score in a test is just a rough indication, like u could have not slept the night before and so performed a little worse or whatever
dont pressure your kids, but make em study and give them motivation... just dont kill them with only 6.5 hours sleep a night
edit: corrected typo which made a serious statement seem amusing