Universal Densitometer

Every Photo Lab Should Have One

Every Photo Lab Should Have One

I’m skeptical about scientific studies as interpreted by the news. I’ve followed many studies over the years and briefly worked in clinical trials. It’s important to ask how the study was conducted and not just run away with the conclusion.

I once read about a study of the effects of race on heart disease. The investigators were trying to find a correlation between African ancestry and hypertension.

This was before DNA testing became something people do for kicks, so how to measure, in a group of American study subjects, the amount of African ancestry?

The scientist had an answer. They measured the subject’s skin tone with a Universal Densitometer. Wow! Can’t get more scientific than that. And the densitometer generates numbers. Numbers are good. They can be put in charts and graphs. Yes, there was a picture of a Black guy waving his hand under a Universal Densitometer.

The only problem is– this was probably the wrong tool for the job. I used a Densitometer when I worked in a photo lab. It did indeed generate numbers. It was a very sensitive machine. So sensitive that you could insert the same color photo and get a different reading every time.

If you wanted an accurate color reading, you were better off asking that lady named Babs, who had a good eye for it, and had been doing it for years.

Measuring race by skin tone seems doubtful anyway. Maybe the guy waving his hand under the machine has cold hands. Maybe he went to the beach and got a tan. Maybe all this weirdness is making his blood pressure go up.

The Journal of The American Heart Association has a good article about the difficulty of constructing a scientific study involving race when race is such a confusing and fraught concept…

The rationale for gathering data using this [racial] model appears to have no clear evidentiary foundation (in terms of the dynamics of human evolution, for example) but grows out of the social reality in which scientists work. We have previously described this process as “circularity.”6 Investigators begin with the social reality of racial difference and are motivated by this reality to hypothesize the existence of significant biologic difference. They gather facts based on this theory, accumulating examples of difference for a melange of unrelated physiological quantities, and they conclude that the groups are in fact different. This conclusion of difference is seen as the end in itself, although it merely restates the social reality as putative scientific reality.

Where ‘circularity’ really spins out of control is the dumbing down of scientific studies in the popular press.

Most of us are not equipped to evaluate the accuracy of science news, but it’s not that hard to tell when something’s not quite right. When the news runs a ‘man bites dog’ story that’s high in sensationalism and vague on facts, it’s fair to ask some questions. The man in the white coat may be right, but he may be wrong. He often is.

[No disrespect intended to Labex Engineering Corporation and their fine products. Their Densitometer is probably way higher quality than the crummy one I used.]

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