How do you prevent mannerism?

Don't do psychedelic drugs, smoke cigarettes, don't rapidly change unneeded antipsychotics, don't be born in a family with psychosis. Oh, and don't be a guy.

you cant it is hereditory and occurs in children pre-puberty you cant it is hereditory and occurs in children pre-puberty

The key isn't to prevent the craving (it's just a biological part of being human), but to satisfy it without piling on the calories. Try eating a small portion of a sweet cereal, or something else...

You can not prevent dyslexia, it is either ruin families so inherited or you can get from trauma like a car crash but it slightly different and can go away after while.