Which is it? Lead or stress

Impaired neural development. Impaired language development and memory. Impaired ability to escape poverty for the rest of the child's life. These are the effects that neuroscientists have found in many children growing up in very poor families with low social status. These scientists claim these children have high levels of...no, not lead, they have high levels of "stress hormones."

These are indeed the findings presented recently at the American Association for the Advancement of Science. Stress hormones are associated with poverty, they claim, and these stress hormones permanently trap these children into lifetime poverty.

But if research shows that very much the same effects result from elevated blood lead levels in children, which is it that is causing the effect: lead or stress?

The scientists who claim it is lead also claim that they have made sure in their research to eliminate "confounding" factors, that is, other causes of the observed effects. But they missed this one, apparently. Maybe stress leads to lifetime poverty and elevated lead levels in poor children. Meanwhile, the scientists who are focusing on stress hormones may be forgetting about lead as a confounding factor in
THEIR research. Maybe lead causes stress which causes impaired neural development and lifetime poverty.

Are the scientists telling us the truth? Or are they all mixed up and confused? We think the latter.