Menus Subscribe Search

Follow us


Genes Are Us

body-makeup

(Photo: watchara/Shutterstock)

Why Our Molecular Make-Up Can’t Explain Who We Are

• August 29, 2014 • 8:00 AM

(Photo: watchara/Shutterstock)

Our genes only tell a portion of the story.

Every Friday this month we’ve taken a look at the relationship between the social and the biological—specifically, how and why the former becomes the latter. This is the the final installment.

Can the behavior of molecules and cells explain human behavior? The question of how the social becomes biological is, in one sense, about linking social effects with biological causes. Those causes are now more accessible than ever, thanks to new tools that researchers use to get under the hood in biology. But are we really connecting cause with effect? A close look at this research reveals a giant gap in our understanding of the relationship between molecular and human behavior. It’s a gap that we will rarely bridge.

At first glance, you would think we have ample reason to be optimistic. For much of the history of genetics, scientists couldn’t study our genes directly. Now, in the aftermath of the Human Genome Project, that’s no longer the case. We have the ability to directly analyze all human genes. We have a rapidly expanding catalog of genes and their molecular functions. And nearly every week, new studies report genetic differences between people that are correlated with differences in particular traits, including social ones such as personality, political orientation, and educational attainment.

Genetic studies of social traits grab headlines, but they can mislead us into thinking that scientists are explaining more than is really the case.

But when you dig into the results, you’re quickly confronted with a major gap in our understanding. Even if you take the study results as given (which you shouldn’t), there is a lot left to explain. We may know the identity of a relevant gene, and we may even know how that gene functions inside the cell. But we usually have absolutely no idea how that function influences the behavior of a complete, living person—we don’t have an unbroken chain of cause and effect linking molecular behavior to human behavior. We don’t even come close; we’re not explaining the biological basis of something like educational attainment by merely listing associated genes like LRRN2, MDM4, and PIK3C2.

This problem isn’t limited to genetic studies of social traits in humans; it’s faced by all biologists interested in the molecular underpinnings of life, including those who study laboratory animals under highly controlled conditions. We have amassed a tremendous inventory of molecular parts, but in most cases, we’re unable to reason from molecules out to the traits of an entire organism. It’s a problem that we’re unlikely to solve. Aside from some exceptions—such as the molecular basis of blond hair in some Europeans—there is no reason to think that we’ll ever explain biology from molecules alone.

Why not? One way to see the problem is to compare biology with a science where we can explain large-scale behavior in terms of molecules: physics. Physical scientists can explain the properties of solids, liquids, and gases by writing down an equation that describes the quantum behavior of individual atoms. That equation then directly connects the function of the whole with the properties of its parts—the overall qualities of, say, a semi-conductor are explained by the features of trillions of individual silicon atoms. The reason biologists can’t do this is obvious: Biology is too complex. Living things are made up of too many different kinds of parts, organized in fantastically complex ways, all responding to each other and to the environment. And social behaviors in particular tend to involve many different parts. The gap between a molecular cause and a behavioral effect is too great. Outside of the most limited cases, we’ll never be able to span it with a complete chain of deductive reasoning.

In other words, we shouldn’t expect a biological explanation of social traits to look like physics. We have to be more pragmatic in the kinds of explanations we look for. Sometimes the explanation will be an exercise in statistics, as in “genes explain 66 percent of the variation in reading ability.” In other cases, particularly pathological ones, a molecular explanation is more useful—knowing that a defective histidine decarboxylase enzyme causes Tourette syndrome, even if we can’t say why, opens up new options for treatment. Useful biological explanations will often bypass molecules and work instead on a higher level, such as the connection between alcohol abuse and the function of different regions of the brain. As the philosopher Philip Kitcher once put it, sometimes “it’s irrelevant whether the genes are made of nucleic acid or of Swiss cheese.”

Regardless of what kinds of biological explanations we resort to, we have to recognize that any answer to the question of how the social becomes biological will be a partial one. And that can be dangerous. When we’re unsatisfied with incomplete explanations, we may look to fill the gaps with facile answers supported by weak or no evidence. Genetic studies of social traits grab headlines, but they can mislead us into thinking that scientists are explaining more than is really the case. It’s hard to see how understanding the detailed workings of phosphatidylinositol-4-phosphate 3-kinase will ever tell us much about why some people succeed more than others at school, or how studying N(alpha)-acetyltransferase 15 will be of much help in understanding why people adopt a certain political orientation. How and why the social becomes biological is an important and fascinating question, but we shouldn’t expect genes to always be a useful answer.

Michael White
Michael White is a systems biologist at the Department of Genetics and the Center for Genome Sciences and Systems Biology at the Washington University School of Medicine in St. Louis, where he studies how DNA encodes information for gene regulation. He co-founded the online science pub The Finch and Pea. Follow him on Twitter @genologos.

More From Michael White

A weekly roundup of the best of Pacific Standard and PSmag.com, delivered straight to your inbox.

Recent Posts

December 20 • 10:28 AM

Flare-Ups

Are my emotions making me ill?


December 19 • 4:00 PM

How a Drug Policy Reform Organization Thinks of the Children

This valuable, newly updated resource for parents is based in the real world.


December 19 • 2:00 PM

Where Did the Ouija Board Come From?

It wasn’t just a toy.


December 19 • 12:00 PM

Social Scientists Can Do More to Eradicate Racial Oppression

Using our knowledge of social systems, all social scientists—black or white, race scholar or not—have an opportunity to challenge white privilege.


December 19 • 10:17 AM

How Scientists Contribute to Bad Science Reporting

By not taking university press officers and research press releases seriously, scientists are often complicit in the media falsehoods they so often deride.


December 19 • 10:00 AM

Pentecostalism in West Africa: A Boon or Barrier to Disease?

How has Ghana stayed Ebola-free despite being at high risk for infection? A look at their American-style Pentecostalism, a religion that threatens to do more harm than good.


December 19 • 8:00 AM

Don’t Text and Drive—Especially If You’re Old

A new study shows that texting while driving becomes even more dangerous with age.


December 19 • 6:12 AM

All That ‘Call of Duty’ With Your Friends Has Not Made You a More Violent Person

But all that solo Call of Duty has.


December 19 • 4:00 AM

Food for Thought: WIC Works

New research finds participation in the federal WIC program, which subsidizes healthy foods for young children, is linked with stronger cognitive development and higher test scores.


December 18 • 4:00 PM

How I Navigated Life as a Newly Sober Mom

Saying “no” to my kids was harder than saying “no” to alcohol. But for their sake and mine, I had to learn to put myself first sometimes.


December 18 • 2:00 PM

Women in Apocalyptic Fiction Shaving Their Armpits

Because our interest in realism apparently only goes so far.


December 18 • 12:00 PM

The Paradox of Choice, 10 Years Later

Paul Hiebert talks to psychologist Barry Schwartz about how modern trends—social media, FOMO, customer review sites—fit in with arguments he made a decade ago in his highly influential book, The Paradox of Choice: Why More Is Less.


December 18 • 10:00 AM

What It’s Like to Spend a Few Hours in the Church of Scientology

Wrestling with thetans, attempting to unlock a memory bank, and a personality test seemingly aimed at people with depression. This is Scientology’s “dissemination drill” for potential new members.


December 18 • 8:00 AM

Gendering #BlackLivesMatter: A Feminist Perspective

Black men are stereotyped as violent, while black women are rendered invisible. Here’s why the gendering of black lives matters.


December 18 • 7:06 AM

Apparently You Can Bring Your Religion to Work

New research says offices that encourage talk of religion actually make for happier workplaces.


December 18 • 6:00 AM

The Very Weak and Complicated Links Between Mental Illness and Gun Violence

Vanderbilt University’s Jonathan Metzl and Kenneth MacLeish address our anxieties and correct our assumptions.


December 18 • 4:00 AM

Should Movies Be Rated RD for Reckless Driving?

A new study finds a link between watching films featuring reckless driving and engaging in similar behavior years later.


December 17 • 4:00 PM

How to Run a Drug Dealing Network in Prison

People tend not to hear about the prison drug dealing operations that succeed. Substance.com asks a veteran of the game to explain his system.


December 17 • 2:00 PM

Gender Segregation of Toys Is on the Rise

Charting the use of “toys for boys” and “toys for girls” in American English.


December 17 • 12:41 PM

Why the College Football Playoff Is Terrible But Better Than Before

The sample size is still embarrassingly small, but at least there’s less room for the availability cascade.


December 17 • 11:06 AM

Canadian Kids Have a Serious Smoking Problem

Bootleg cigarette sales could be leading Canadian teens to more serious drugs, a recent study finds.


December 17 • 10:37 AM

A Public Lynching in Sproul Plaza

When photographs of lynching victims showed up on a hallowed site of democracy in action, a provocation was issued—but to whom, by whom, and why?


December 17 • 8:00 AM

What Was the Job?

This was the year the job broke, the year we accepted a re-interpretation of its fundamental bargain and bought in to the push to get us to all work for ourselves rather than each other.


December 17 • 6:00 AM

White Kids Will Be Kids

Even the “good” kids—bound for college, upwardly mobile—sometimes break the law. The difference? They don’t have much to fear. A professor of race and social movements reflects on her teenage years and faces some uncomfortable realities.



Follow us


Don’t Text and Drive—Especially If You’re Old

A new study shows that texting while driving becomes even more dangerous with age.

Apparently You Can Bring Your Religion to Work

New research says offices that encourage talk of religion actually make for happier workplaces.

Canadian Kids Have a Serious Smoking Problem

Bootleg cigarette sales could be leading Canadian teens to more serious drugs, a recent study finds.

The Hidden Psychology of the Home Ref

That old myth of home field bias isn’t a myth at all; it’s a statistical fact.

The Big One

One in two United States senators and two in five House members who left office between 1998 and 2004 became lobbyists. November/December 2014

Copyright © 2014 by Pacific Standard and The Miller-McCune Center for Research, Media, and Public Policy. All Rights Reserved.