I only have a moment tonight. But I want to post a tidbit from a current read: "Our Stolen Future" by Colborn, Dumanoski and Myers.
On pg 191-192, they are discussing the potential effects of PCBs in contaminated fish on children whose parents ate said fish. A psychologist named Helen Daly has been studying behavioral changes in rats fed Lake Ontario fish. The expected results of her test (which involved feeding a small group of rats a diet 30% fish) was that the diet would turn them into dummies. It would affect their brains and intelligence level. This seems a plausible expectation for the consumption of toxic chemicals.
However, they found behavioral changes that were unexpected. While there were no signs of learning deficits, indicating that intelligence levels were not adversely effected, the rats showed distinct behavioral changes. Standard testing showed decreased activity.
This behavioral change has been demonstrated repeatedly.
Rats fed a diet of 30% contaminated fish (fish that have been raised in Lake Ontario) over react to even mildly negative situations. Daly describes them as "Hyper-reactive". When comparing hteir reactions to humans, Daly is quoted as stating "Every little stress will be magnified."
Some studies done on children with high known levels of exposure have indicated a possible correlation to human experience.

Does this remind anyone else of Sensory Processing/Integration Disorders? Or Highly Sensitive Children?

PCBs aren't only found in fish. They were used as plasticizing agents in paint, flexible plastic coating for electrical wires, caulking agents, dusting products, flame retardants, adhesives and pesticide extenders. They do not degrade readily, so are still present in our environment. They tend to accumulate in lakes and rivers, where they bind with plant life and are consumed by sea life. The higher the animal on the food chain, the higher the concentration of PCBs and other chemical contaminants. (Interesting side note: PCB production was taken over in 1929 by non other than our beloved Mons*nto, the GM corn giants.)

One of Daly's most disturbing findings is that pcb effects are seen in second generation rats. So if rat generation A eats PCB laden fish, generation B is affected, but fed only a carefully monitored diet of PCB free fish, the researchers are still seeing abnormal reactions in generation C.

In other words, what scientists unleashed on our grandparents is haunting us today. What we do with our bodies, wittingly or unwittingly, will continue to affect our grandchildren regardless of whether we are here to play a part in it.

Of course, this has nothing to do with corn. But it's interesting all the same.
In the end it's still just stress. Stress on our environment, stress on our bodies, stress on our children. However, these studies show that somehow we may be inhibiting their inborn ability to handle stressful situations.

This isn't an answer. But it sure seems like a significant piece of many puzzles our society faces.