Confounding Variables

Identifying causality is important for addressing environmental problems. Confounding variables can cause misinterpretations of causality.

A confounding variable is present when something influences both our independent variable and our dependent variable, creating a correlation between them. However, that relationship is not causal.

We discussed the example of breath mints and lung cancer. We imagine that these are correlated and that increased use of breath mints creates a higher risk of lung cancer. In this case, the confounding variable is cigarette smoking since cigarette smoking causes breath mint use and an elevated risk of lung cancer.

Racism as a Confounding Variable

Before getting into such a difficult topic, we should state that no one wants to be called a racist, and that all of us are more than a statistic. That said, many of the systems we participate in have racist outcomes that we’d like to make more fair. It may be psychologically safer to ask if our laws and systems have racist outcomes than to ask about people.

In the United States, “race” is an important predictor of employment, maternal mortality, educational attainment, and wealth. Many have therefore concluded that “race” causes these things. Scholars have provided evidence that racism is a confounding factor since racism causes both “race” and these different outcomes between “races”.

Hereditarian hypothesis

As early as the enlightenment, scholars hypothesized that humans were divided into races and that these races had essential qualities of intelligence and sociability. In 1969 Arthur Jensen wrote that genes cause IQ differences and that educational interventions would not succeed since they couldn’t change genetics.

This hypothesis assumes that race and/or genetics is the independent variable or cause and that intelligence and educational outcomes are the dependent variable or result.

Environmental Racism hypothesis

This hypothesis holds that racism causes folks of different races to be exposed to different levels of environmental contaminants and that these contaminants are an independent variable or cause. The dependent variable is intelligence and educational outcomes caused by exposure to environmental contaminants.

Hereditarian evidence

Population geneticists have rejected attempts to create causal links between genes, “race”, and intelligence. While important books promoting a hereditarian hypothesis have been written and read, scientists have not supported their conclusions. After the book “A Troublesome inheritance” was published, 139 scientists signed a letter saying their work had been misrepresented and misinterpreted in the book.

Environmental Racism evidence

Solid epidemiological evidence exists for relationships between lead exposure and crime and intelligence. We also have evidence linking increased exposure to pollution to minority communities for decades in the United States.

Taken together, these relationships lend evidence to the hypothesis that racism exposes different samples of our population based on race to environmental toxins differently and that these exposures lead to differences in IQ and educational performance.

Harriet Washington’s book, A Terrible Thing to Waste has an excellent compilation of this evidence.

Hereditarian residue

Many of us harbor beliefs that are based in a hereditarian hypothesis.

Implications

Race continues to be an important factor in American life.

Social scientists have come up with measures of racial resentment and anti-immigrant sentiments. These measures have been shown using regression analysis to predict voting outcomes.

The evidence strongly suggests that major patterns of american life are rooted in a hereditarian theory that is as spurious as believing increased ice cream sales cause violent crime or that the use of breath mints leads to lung cancer. All of these are examples of confounding variables.