The Evolution of Morality
Soazig Le Bihan -- University of
Montana
1
Outline
Introduction
Problem 1: How could morality be the result of evolution?
The new science of morality
Problem 2: Morality debunked?
Conclusion
Soazig Le Bihan -- University of
Montana
2
Outline
Introduction
Problem 1: How could morality be the result of evolution?
The new science of morality
Problem 2: Morality debunked?
Conclusion
Soazig Le Bihan -- University of
Montana
3
Introduction
Evolution and Morality
P1. Human behavior is the result of evolutionary forces
P2. Human beings behave as moral agents
CC: Moral behavior is the result of evolutionary forces
 We should be able to explain human moral
behavior in terms of evolutionary forces
Soazig Le Bihan -- University of
Montana
4
Introduction
Two Problems
PROBLEM 1:
P1: The law of evolution is a law of competition
P2: Moral behavior includes seemingly non-competitive
behavior – cooperation, altruism, sacrifice
CC: Evolution cannot explain moral behavior
 If evolution is a matter of competition, how could
moral behavior have been selected?
Soazig Le Bihan -- University of
Montana
5
Introduction
Two Problems
PROBLEM 2:
P1: Evolution explains human behavior in terms of
biological processes which are determined and have
no “truth” to them
P2: Moral behavior properly speaking is free and has value
only if it based on truths
CC: “If evolution is right, then there is no moral behavior
properly speaking”
 If moral behavior is the result evolution, is not
morality an illusion?
Soazig Le Bihan -- University of
Montana
6
Outline
Introduction
Problem 1: How could morality be the result of
evolution?
The new science of morality
Problem 2: Morality debunked?
Conclusion
Soazig Le Bihan -- University of
Montana
7
How could moral behavior result from
evolution?
PROBLEM 1:
P1: The law of evolution is a law of competition
P2: Moral behavior includes seemingly non-competitive
behavior – cooperation, altruism, sacrifice
CC: Evolution cannot explain moral behavior
THREE ANSWERS:
1. Moral behavior as a side effect
2. Biological Altruism
3. Selection of cooperative behavior
Soazig Le Bihan -- University of
Montana
8
1. Moral behavior as a side effect
Non-adaptive traits as a side effect:
- The development of the human brain is the result of
evolution
- Moral behavior comes as a non-adaptive side effect
Other Examples:
- Nerdy behavior
- Taste for sweets and fats
 Moral behavior could be a non-adaptive side effect
of the development of the brain
Soazig Le Bihan -- University of
Montana
9
2. Biological Altruism
Biological altruism
- Reciprocal aid
- Kin selection
Other Examples:
- Vervet monkeys’ calls
- Insect colonies
 Human moral behavior could be a case of
biological altruism
Soazig Le Bihan -- University of
Montana
10
3. Selection of cooperative behavior
The Problem: parasites
Prisoner’s dilemma
Jones cooperates
Jones cheats
Smith cooperates
Jones: 3 kids
Smith: 3 kids
Jones: 5 kids
Smith: 0 kid
Smith cheats
Jones: 0 kid
Smith: 3 kids
Jones: 1 kid
Smith: 1 kid
Simulation type 1:
- Single encounter:
- Best strategy: parasite
- Paradox: both lose in trying to win!
Soazig Le Bihan -- University of
Montana
11
3. Selection of cooperative behavior
Simulation type 2:
- Repeated encounters
- Memory of past encounters
- Best strategy: “tit for tat”
 Cooperative behavior selected in the long run
Soazig Le Bihan -- University of
Montana
12
How could moral behavior result from
evolution? -- Conclusion
PROBLEM 1:
If the law of evolution is a law of competition, could
moral behavior, including cooperation, altruism
and sacrifice, be selected?
ANSWER: Of course it could!
Cooperative behavior, altruism and sacrifice can be
the most competitive behavior in certain
environments.
Soazig Le Bihan -- University of
Montana
13
Outline
Introduction
Problem 1: How could morality be the result of evolution?
The new science of morality
Problem 2: Morality debunked?
Conclusion
Soazig Le Bihan -- University of
Montana
14
The New Science of Morality
The Moral Sense Test
- Harvard University
- More than 300,000 subjects
- All background: religion, age, culture, education
 How do humans decide what is right and wrong?
Soazig Le Bihan -- University of
Montana
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The New Science of Morality
The Trolley Problem
Situation 1: Is it morally permissible to pull the switch?
Soazig Le Bihan -- University of
Montana
16
The New Science of Morality
The Trolley Problem
Situation 2: Is it morally permissible to push the fat guy?
Soazig Le Bihan -- University of
Montana
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The New Science of Morality
The Trolley Problem
Results:
- Two situations similar from a rational point of view
- But people’s choices differ
Interpretation: Hauser:
- Irrational intuitions (gut reactions), not rational reasoning,
are at work in our moral judgments
- These intuitions (gut reactions) are the result of
evolutionary processes
- Fat man: avoid interpersonal violence
Soazig Le Bihan -- University of
Montana
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The New Science of Morality
Neurobiology
Results:
- Brain damage – loss of moral sense
- MRI: instincts vs rational reasoning in moral judgments
 At least part of our moral judgments are influenced
by some biological instincts – a “moral instinct”.
Soazig Le Bihan -- University of
Montana
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The New Science of Morality
Universal Grammar
Chomski and language learning:
- Universal grammar: innate
- Particulars of each language: culture
Similar idea in the moral domain:
- Universal grammar: innate
- Particulars of each morality: culture
 Pinker: “the primary colors of our moral sense”
Soazig Le Bihan -- University of
Montana
20
The New Science of Morality
Conclusion
Psychological and Neurological research:
Moral judgments are at least partly influenced by a
“moral instinct”, which is part of our biological
make up, resulting from the long process of
evolution
Hauser and Joyce:
This shows that morality is an mere illusion.
Does it follow? See Pinker
Soazig Le Bihan -- University of
Montana
21
Outline
Introduction
Problem 1: How could morality be the result of evolution?
The new science of morality
Problem 2: Morality debunked?
Conclusion
Soazig Le Bihan -- University of
Montana
22
Morality debunked or strengthened?
PINKER:
"So, dissecting moral intuitions is no small matter. If
morality is a mere trick of the brain, some may fear,
our very grounds for being moral could be eroded. Yet
as we shall see, the science of the moral sense can
instead be seen as a way to strengthen those grounds,
by clarifying what morality is and how it should steer
our actions"
 Pinker: Morality not debunked but strengthened!
How?
Soazig Le Bihan -- University of
Montana
23
Morality debunked or strengthened?
Two Arguments
1. Argument for Determinism:
P1. If our moral behavior results from our biological make
up, then it is determined.
P2. Moral behavior is true moral behavior only if it results
from free will
CC. There is no true moral behavior -- illusion
 Are we biologically determined to make the “moral”
choices we make?
Soazig Le Bihan -- University of
Montana
24
Morality debunked or strengthened?
Two Arguments
2. Argument for Relativism:
P1. Whether a trait is selected by evolution depends on
whether or not such trait is beneficial to survive in a
certain environment.
P2. Whether or not such trait is beneficial to survive in a
certain environment has nothing to do with it being
right or wrong
CC. If our moral behavior is a trait selected by evolution,
then it has nothing to do with right or wrong, ie:
- moral behavior is not grounded in moral truths
 Is our “moral” behavior just another mean to
survive?
Soazig Le Bihan -- University of
Montana
25
Morality debunked or strengthened?
Against the Argument for Determinism
Are we biologically determined to make the moral choices
we make? Seriously? – Princeton party
Three Levels:
- Universal Grammar: tool kit for building particular
systems of morality
- But the particular systems come from other sources !
 The universal grammar gives the primary colors: it
remains to design the full painting!
Soazig Le Bihan -- University of
Montana
26
Morality debunked or strengthened?
Against the Argument for Determinism
Three Levels:
- Universal Grammar: tool kit
- Culture and Education: particulars – but we know it is not
enough
- Intellectual Autonomy: reflection and modification
 There is no biological determinism for moral
behavior
Soazig Le Bihan -- University of
Montana
27
Morality debunked or strengthened?
Against the Argument for Relativism
Is our “moral” behavior just another mean to survive?
Compare with mathematics:
- We are born with a evolutionary-driven rudimentary
mathematical knowledge – monkeys too!
- We build on it with mathematical reasoning and discover
mathematical truths
 From the fact that a rudimentary version of our
mathematical knowledge is the result of
evolution, it does not follow that we cannot build
autonomous, true knowledge!
Soazig Le Bihan -- University of
Montana
28
Morality debunked or strengthened?
Against the Argument for Relativism
Then for morality:
- We are born with a evolutionary-driven rudimentary
moral tool-kit
- We build on it with rational reasoning and discover moral
truths
 There is no reason to reject the idea that that there
are moral truths if we admit the existence of
mathematical truths
Soazig Le Bihan -- University of
Montana
29
Morality debunked or strengthened?
Conclusion
Evolutionary forces explain rudimentary versions
some of our tendencies toward moral behavior,
and some of the content of our moral thoughts.
But evolution is not the whole story:
- There is no determinism of moral behavior
- From the fact that some rudimentary version of
morality is the result of evolution, it does not
follow that there are no moral truths
 Autonomous rational thinking is what makes moral
behavior and moral thoughts truly moral.
Soazig Le Bihan -- University of
Montana
30
Conclusion
PINKER:
"Far from debunking morality, then, the science of the
moral sense can advance it, by allowing us to
see through the illusions that evolution and
culture have saddled us with and to focus on
goals we can share and defend. As Anton
Chekhov wrote, “Man will become better when
you show him what he is like.” "
Soazig Le Bihan -- University of
Montana
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