When Similar Looks, Genes, and Behavior Align

Doppelgängers are having a moment. These are people who look alike, despite being nominally unrelated. Canadian artist François Brunelle is commanding attention all over the world for his I’M NOT A LOOK-ALIKE! photography project, which he started in 1999. At the same time, a study this week in Cell Reports tells us that looks, genes, and behavior can align in remarkable ways to remind us of the power of genetic traits.

Appearance, Genes & Behavior

Ricky Joshi and colleagues recruited pairs of people who were unrelated doubles from Brunelle’s project. They used facial recognition algorithms to confirm the similarity of facial appearances. Then they analyzed and compared their genes, their epigenetic variations, and even their microbiomes.

Their findings confirm that similar human likenesses come from shared genetic traits. DNA methylation (epigenetics) and microbiomes explain very little of it. They also found these people shared not only facial looks and genes, but also other physical features and aspects of their behavior. The authors explain:

“Physical traits such as weight and height as well as behavioral traits such as smoking and education were correlated in look-alike pairs, suggesting that shared genetic variation not only relates to shared physical appearance but may also influence common habits and behavior.

“Overall, we provided a unique insight into the molecular characteristics that potentially influence the construction of the human face. We suggest that these same determinants correlate with both physical and behavioral attributes that constitute human beings.”

Remember This

It’s hard for people to accept, but this is a big reminder that behavior doesn’t merely come from the choices we make. It has roots in our genes. Misunderstanding the biological basis for our behavior – as well as our appearance – is the primary reason that most people understand obesity so poorly. The prevalent fiction is that people choose their body size and shape.

We do not choose the body we inherit. We get it with all its vulnerabilities, with some behavioral tendencies, and with all its amazing beauty. We also inherit a world that presents us with challenges – both physical and emotional. And then, we have to figure out how to live with all of it.

Click here for the study in Cell Reports and here for the I’M NOT A LOOK-ALIKE! project of François Brunelle. For further perspective, click here, here, and here.

The Twins, painting by Boris Grigoriev / WikiArt

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August 27, 2022

2 Responses to “When Similar Looks, Genes, and Behavior Align”

  1. August 28, 2022 at 8:45 am, John DiTraglia said:

    Another strike against environment as an explanation of the epidemic. and also epigenetics and the microbiome. it’s still a conundrum.

    • August 28, 2022 at 10:44 am, Ted said:

      Yes, the environment doesn’t explain why some people develop obesity and others do not. But it’s hard to argue that changes in our physical and food environment have not prompted some of the increase we’ve seen in obesity prevalence.