Moral values and biology
Dimension 1: How biology affects a person’s moral values
This is a completely different question.
Instead of asking
“How does biology change ethics?”
it asks
“How does biology shape the moral decisions of individuals?”
Here biology plays a surprisingly large role.
A. Genes
Twin studies suggest that some aspects of personality are partly inherited.
These include tendencies toward
- empathy
- aggression
- impulsiveness
- risk taking
None determines morality.
But they influence it.
B. Hormones
Hormones affect social behavior.
Examples:
Oxytocin
often increases
- bonding
- trust
- attachment
Testosterone
can increase
- competitiveness
- dominance
- status seeking
Neither hormone makes someone moral or immoral.
They only shift tendencies.
C. Brain structure
Damage to certain brain regions can radically change moral behavior.
One famous historical example is Phineas Gage.
After an iron rod passed through his frontal lobe,
friends said
“Gage is no longer Gage.”
His judgment and social behavior changed dramatically.
His case helped demonstrate that morality depends partly on brain function.
D. Mental illness
Certain disorders affect
- empathy
- impulse control
- emotional regulation
Again,
biology influences moral behavior
without eliminating responsibility in every case.
E. Aging
Children, adults and elderly people often differ biologically.
Brain development changes
- impulse control
- long-term planning
- empathy
One reason we judge children differently is biological maturation.
F. Fatigue, hunger and illness
This is one of my favorite examples because it shows morality operating in everyday life.
Someone who is
- exhausted
- hungry
- sleep deprived
- in chronic pain
often becomes
- impatient
- less generous
- quicker to anger
The person’s moral principles may not change.
Their biology temporarily changes their ability to act on them.
The interaction between the two dimensions
These two dimensions constantly influence each other.
Knowledge about biology changes society’s moral judgments.
Biology changes people’s behavior.
Then society adjusts its morality again.
It’s a continuous feedback loop.
For example:
- Neuroscience discovers brain disorders.
- Society becomes less punitive.
- Laws change.
- People’s attitudes change.
- Research continues.
Science and morality influence one another without being identical.
Dimension 2: How our knowledge of biology affects our moral values
This asks:
Can learning more about biology change what we consider morally right or wrong?
Notice this is not asking whether biology determines morality. Rather, it asks whether scientific discoveries can lead us to revise our ethical judgments.
I think the answer is clearly yes, although indirectly.
A. Better knowledge changes moral responsibility
For centuries people blamed individuals for things we now understand biologically.
Examples:
- epilepsy → once viewed as demonic possession
- autism → once blamed on poor parenting
- schizophrenia → viewed as moral weakness
- addiction → often seen purely as a vice
Biology changed our moral evaluation.
Instead of saying
“He is a bad person”
we may now ask
“Is this partly a neurological disorder?”
Knowledge increased compassion.
B. Biology expands our moral circle
When biology demonstrated that many animals
- feel pain
- experience fear
- grieve
- cooperate
- form friendships
our ethics changed.
For example:
- animal welfare laws
- bans on unnecessary cruelty
- concern for dolphins, elephants, octopuses
These developments were driven partly by biological discoveries.
C. Genetics influences ethics
Modern genetics forces us to ask questions such as
- Should gene editing be allowed?
- Should embryos be screened?
- Should parents modify children’s genomes?
Biology creates entirely new ethical problems.
D. Brain science changes ideas of guilt
Suppose someone has
- a brain tumor,
- frontal lobe damage,
- or a neurological disease.
If that causes violent behavior,
how responsible are they?
Neuroscience doesn’t remove morality.
It complicates it.
E. Evolution changes our understanding of morality
Evolution suggests that
- empathy
- cooperation
- fairness
- reciprocal altruism
did not suddenly appear.
Many evolved because they helped groups survive.
This doesn’t prove morality is “nothing but evolution.”
But it changes how we understand its origins.
Important caution
This is where many people make a logical mistake.
They argue:
“Evolution favors X.”
Therefore
“X is morally good.”
That is incorrect.
This mistake is called the naturalistic fallacy.
Nature contains
- cooperation
- murder
- parasitism
- rape
- cannibalism
Biology tells us what exists, not automatically what ought to exist.
Biology does not determine morality, but it profoundly shapes both the questions morality must answer and the biological capacities through which human beings make moral decisions.
That statement avoids two common extremes:
- Biological determinism: “Our genes completely determine morality.” (Too strong.)
- Pure moral independence: “Biology has nothing to do with morality.” (Also too strong.)
Instead, it recognizes that morality emerges from human beings, who are biological organisms, while also involving reasoning, culture, education, laws, and conscious reflection.