Madeleine- In short, No.

It's an interesting idea, but altering the brain chemistry of a population will not alter their DNA, and it's the DNA that is responsible for passing that population's brain chemistry traits on to the next generation. It's the same as my lifting weights will not result in my children being genetically inclined to be bigger and stronger.

Fearfulness, while it may have a genetic component, is a learned behavior. A fearful population may well raise a suceeding generation that is likely to be more fearful, not as a result of any genetic changes but rather as a result of the children modeling their behavior after their parents behavior.

And, IMHO, and as a totally non-minority white anglo saxon prostetant male, if this zoning crap isn't based in prejudice then I'll eat my freakin' shorts.