Commentary: Don’t assume that one event caused another

Somewhere in your educational history, you learned that correlation does not infer causation. Just because one event occurs before another, or because two events occur simultaneously, does not mean that one event necessarily caused the other.

Here is an obvious example. Children grow in height while attending the seven years of elementary school (kindergarten to sixth grade). But time in school does not cause height. Secretion of hormones directed by the by the pituitary gland during the elementary years causes physical growth. Time is associated with growth but the relationship is not causal.

Often we attribute academic success of children to the school.

A proud parent says, “We are so happy to have moved into this neighborhood. The schools are excellent.”

Of course there is a relationship between instruction at school and learning. But a third variable, socioeconomic-status (SES), has a larger relationship. SES is measured by family income, wealth, ZIP code and the educational attainment and occupational status of the parents. The beaming parent quoted in this example is insightful to identify the neighborhood as a variable affecting her child’s learning.

Recently, we witnessed a series of horrific events in the island nation of Sri Lanka. Islamic extremists killed hundreds of church-going Christians on Easter Sunday and injured some 500 more. A relationship between religion (in this case Islam) and murder occurred. One might assume that, as the perpetrators were Muslims, Islam caused this horror.

Religious fanaticism, present in many faiths, likely teamed with countless other factors, to cause the calamity.

Breastfeeding is associated with a number of positive developmental outcomes for the infant, including increased intelligence, health, life expectancy, future academic achievement and many others. Mother’s milk is readily digested and provides an outstanding source of nutrition.

However, breastfeeding itself does not solely account for these benefits. Research suggests that women who breastfeed, and especially those who do so consistently for the first six months, are of higher SES. Higher SES mothers as well as their infants are advantaged in countless ways, and these advantages collectively contribute to the benefits related to breastfeeding.

In the late 1990’s it was noted that onset of autism seemed to correspond to vaccination for measles, mumps and rubella (MMR). Quickly, and by a leap of blind faith, it was assumed that the MMR vaccination caused autism. This correlation has been closely studied and, fortunately, the relationship between MMR vaccination and onset of autism is not causal.

It turns out that the symptomatology of autism frequently is identifiable around the age that MMR vaccination occurs. Imagine the resulting health disaster if parents did not immunize their children in order to protect them from autism.

Again in the 1990’s it was observed that women who received hormone replacement therapy (HRT) to treat menopausal symptoms also exhibited lower rates of cardiovascular disease. Does HRT cause cardiovascular health? It turns out that women who undergo HRT are of higher SES than those who don’t. Characteristics related to SES causes better cardiovascular health, not HRT.

Currently the U.S. economy is firing on all cylinders, growth is consistent and unemployment is at historically low levels. All this while President Trump occupies the White House. It might be assumed that efforts of the administration have caused this ongoing expansion.

Again, correlation does not infer causation. Trump inherited a healthy economy and many economists note that the economy is largely independent of political activities in Washington. Nonetheless, it is hoped that Trump continues to bask in this good fortune.

Our brains dislike chaos and seek order and predictability. As a result, we tend to erroneously infer that associated events demonstrate a causal relationship. What are we to do?

The solution may well exist in the classroom. Educators are at their best when imparting knowledge to their students. Possessing a broad range of knowledge empowers us to recognize relationships that are causal and those that are not. Furthermore, training in critical thinking may help.

Students need to be taught to question conclusions, seek understanding at a deeper level, employ reasoning and logic in problem solving and, when possible, employ scientific methodology to draw valid conclusions.

| Courtesy Photo John Seaman

John M. Seaman, Ph.D., is a retired school psychologist and a retired adjunct professor of psychology at Salt Lake Community College.

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