Gene Testing for Behavior: Dangerous or Revolutionary?

The idea of predicting a child’s intelligence or behavioral tendencies before birth once belonged to science fiction. But today, with the convergence of advanced genomics and artificial intelligence, this possibility is edging closer to reality. Scientists are beginning to identify patterns in the human genome that may — even if weakly — be associated with cognitive traits such as intelligence, impulsivity, empathy, and even aggression.
While the science remains far from perfect, the implications are real and pressing. As clinicians, scientists, and ethicists grapple with these developments, key questions arise:
Should parents be permitted to screen embryos for potential cognitive capabilities?
Should gene-based behavioral predictions influence school placements or even hiring practices?
At what point does this shift from predictive health to a modern version of eugenics?

This article explores the evolving landscape of genetic screening for intelligence and behavior, unpacking the science, examining the ethical tensions, and analyzing what it means for future medical practice.

1. WHAT IS GENETIC SCREENING FOR INTELLIGENCE AND BEHAVIOR?

Genetic screening involves the analysis of DNA to detect specific traits, conditions, or risk profiles. Traditionally, its primary applications included:

• Identifying monogenic diseases such as Tay-Sachs or cystic fibrosis
  
  
• Assessing predisposition to conditions like breast or ovarian cancer
  
  
• Carrier screening in reproductive contexts, particularly with IVF
  

Today, however, attention is shifting to a new frontier — screening for non-disease traits like:

• Cognitive ability
  
  
• Educational attainment
  
  
• Personality attributes such as impulsivity or introversion
  
  
• Risk of behavioral or psychiatric conditions
  

The key technology enabling this transition is the polygenic score — a cumulative calculation derived from the influence of many genes, each contributing a minor effect. Applied to large datasets, these scores have been used to forecast IQ, attention span, or behavioral tendencies. Though still controversial and imprecise, they are already being marketed by some companies, particularly in the context of embryo selection.

2. THE SCIENCE: ARE THESE PREDICTIONS EVEN RELIABLE?

The reliability of polygenic scores for traits like intelligence and behavior is a subject of intense scientific debate.

• These traits are polygenic and multifactorial, meaning they result from the interaction of thousands of genes and numerous environmental factors.
  
  
• Each gene identified may contribute only a minuscule fraction to the overall expression of a trait.
  
  
• The environment — including socioeconomic status, educational exposure, family dynamics, and even nutrition — significantly shapes outcomes.
  

As of now, polygenic scores for intelligence can explain only around 10–15% of the variance in general cognitive ability across populations. That leaves a massive margin for unpredictability.

Nonetheless, public interest persists, and companies are already offering genetic insights into such traits, despite the warnings of many scientists and ethicists.

3. PREIMPLANTATION GENETIC TESTING (PGT) FOR TRAITS: A SLIPPERY SLOPE

PGT is a widely accepted component of IVF used to detect chromosomal abnormalities and serious hereditary diseases. However, some clinics now offer expanded PGT panels that include polygenic trait predictions, such as:

• Intelligence
  
  
• Risk of depression or schizophrenia
  
  
• Athletic ability
  
  
• Physical characteristics like height
  

This has triggered concern among bioethicists and medical professionals. Once screening extends beyond medical conditions to desirable attributes, we move into ethically murky territory.

Where do we draw the line?
Do we want to select for brilliance, athleticism, or obedience?
What about children who fall outside these chosen traits?

The concern is clear: we may be moving toward designer babies — and not gradually.

4. THE ETHICAL DILEMMAS DOCTORS AND SOCIETY MUST FACE

Is It Ethical to Rank Embryos by Intelligence?
Even assuming the predictions were accurate (which they are not), does it make ethical sense to value embryos based on presumed cognitive advantage? What message does this send to children with learning challenges or neurodivergent traits?

What About Behavioral “Risk” Genes?
Should we exclude embryos with a higher polygenic score for aggression, impulsivity, or ADHD-like traits? Doing so risks stigmatizing common personality variations and pathologizing normal human diversity before birth.

Consent and Autonomy
A fetus or embryo cannot consent to being selected based on genetic desirability. The idea of shaping a person’s destiny before they are born raises critical questions about autonomy and free will.

Genetic Discrimination
What happens when polygenic data moves beyond families and into institutional settings? Could schools, insurance companies, or employers one day require genomic profiles, opening the door to subtle — or overt — forms of discrimination?

5. THE SPECTER OF EUGENICS: A CAUTIONARY PARALLEL

We cannot discuss this topic without acknowledging the historical parallels. In the early 20th century, the eugenics movement led to horrific policies worldwide, including:

• Compulsory sterilizations
  
  
• Racial “purity” laws
  
  
• Systematic extermination under regimes such as Nazi Germany
  

While today’s technology may appear more refined, the fundamental ethical question remains: are we trying to “improve” humanity through selective genetics?

The difference is not necessarily in intention — it’s in method. And history teaches us that without strict ethical oversight, science can be misused in deeply destructive ways.

6. CULTURAL AND SOCIETAL IMPLICATIONS

In many societies, intelligence is associated with prestige, opportunity, and socioeconomic mobility. In some cultures, gender preferences still dominate family planning decisions. Behavioral traits such as compliance, quietness, or extroversion may also be culturally desirable.

The normalization of genetic screening for such traits raises troubling questions:

• Will diverse personalities be marginalized in favor of a "standardized" human profile?
  
  
• Will global inequality worsen as only affluent families access trait-selection technologies?
  
  
• Could this lead to a dangerous homogenization of thought, talent, and behavior?
  

These developments risk reinforcing social biases, entrenching class privilege, and weakening the value of human diversity.

7. COULD THIS EVER BE REGULATED RESPONSIBLY?

To use this technology ethically, robust legal and policy frameworks are essential. These might include:

• Regulations defining which traits can be tested or selected
  
  
• Licensing and oversight for companies providing polygenic trait testing
  
  
• Independent ethics boards to evaluate new screening technologies
  
  
• Public forums and debates to ensure alignment with societal values
  

Yet regulation often lags behind innovation. With private biotech companies moving faster than governments can legislate, there’s a real danger that unregulated practices will become entrenched before oversight catches up.

8. THE DOCTOR’S ROLE: GATEKEEPER OR FACILITATOR?

As this technology enters clinical practice, healthcare professionals — particularly genetic counselors and physicians — will play a central role. Their responsibilities include:

• Clearly explaining what polygenic scores do and do not mean
  
  
• Counseling prospective parents on the limitations, risks, and ethical concerns
  
  
• Establishing boundaries when requests cross into ethically ambiguous territory
  
  
• Advocating for health equity and responsible use of emerging technologies
  

We must incorporate genomic ethics into medical training. It’s no longer sufficient to understand genetic markers; future physicians must grasp the social and moral context in which they’re used.

9. THE PATIENT’S PERSPECTIVE: HOPE, FEAR, AND PRESSURE

Most parents seeking genetic screening for traits aren’t driven by eugenics — they’re driven by love and hope. They want:

• The best possible life for their child
  
  
• To avoid suffering and hardship
  
  
• To meet societal expectations of success and intelligence
  

But these motivations, however sincere, can foster an unhealthy fixation on perfection. Children risk becoming commodities shaped by parental preferences, rather than individuals nurtured through love and acceptance.

The emotional burden of creating a "perfect" baby may distort the most fundamental human relationship — that between parent and child.

10. FINAL THOUGHTS: OUR GENES DON’T DEFINE OUR WORTH

Genetic screening for intelligence and behavior lies at the intersection of science, ethics, and social values. It holds the promise to:

• Anticipate developmental difficulties early
  
  
• Customize education and behavioral support
  
  
• Help mitigate certain neuropsychiatric disorders
  

But it also threatens to:

• Reduce children to statistical projections
  
  
• Reinforce damaging societal ideals
  
  
• Undermine the value of unpredictability, creativity, and diversity in the human experience
  

For doctors and medical students, the path forward is clear: we must prioritize ethics alongside innovation. We must resist the urge to let technology dictate what kind of people should exist in the world.

Our role isn’t just to inform, but to advocate for a vision of medicine that cherishes life in all its forms — not just the genetically optimized ones.