Cognitive Evolution
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Summary of:
Heyes, C. (2003). Four routes of cognitive evolution. Psychological Review, 110, 713-727.
Summary by Marian Alonso and Paulina Murrietta
For Dr. Mill’s Psyc 452 class, Spring 2008
Human Nativist Evolutionary Psychology (HNEP) claims that the mind is made of
various innate cognitive modules and is the most prominent approach to understanding the
evolution of cognition. Two errors that could arise from this approach are that examples of
adaptive specialization could be interpreted as modular whether or not data actually support such
a claim, and that all of evolutionary psychology could thus be seen as flawed. HNEP asserts that
cognitive evolution occurs through phylogenetic construction—or adaptive changes in cognitive
mechanisms through natural selection—alone. HNEP also doesn’t distinguish between cognitive
and non-cognitive mechanisms, or finds the distinction unimportant, and assumes that natural
selection is the only source of adaptive change, with individual processes as means through
which natural selection achieves such change. The four routes framework discussed in this paper
acknowledges the existence of cognitive modules while simultaneously allowing the
identification of other types of adaptive specialization. In this sense, the framework attempts to
provide all evolutionary psychologists—constructionists, selection theorists and nativists alike—
with a classification system that allows for communication between various schools of thought.
The four routes framework describes four ways in which cognitive processes can change
such that adaptive behavior results from the change. The framework identifies two variables
involved in the evolution of a cognitive process: the evolutionary source and the locus of an
adaptive change (see Figure 1). The two evolutionary sources of change are natural selection, or
gene-based evolution, and developmental selection, the interaction between a developing
organism and its environment. The two loci of adaptive change are the cognitive mechanism
itself, which processes information, and the input to the cognitive mechanism, or the range or
type of information processed by the cognitive mechanism. A route is phylogenetic, or specieslevel, when the source of the adaptive change is natural selection, and ontogenetic, or individuallevel, when the source is developmental selection. The route is called construction when the
locus of change is the cognitive mechanism and inflection when the locus is the input of
information into the cognitive mechanism.
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SOURCE
Figure 1. The four routes framework (Adapted from Heyes, 2003, p. 714)
LOCUS
MECHANISM
INPUT
NATURAL
SELECTION
Phylogenetic
construction
Phylogenetic
inflection
DEVELOPMENTAL
SELECTION
Ontogenetic
construction
Ontogenetic
inflection
If organisms that posses a certain feature of a cognitive process out-reproduce those that
do not posses that feature and did so because they possessed that feature, then such a feature is
said to have evolved phylogentically. If the feature was not explicitly favored by natural
selection but was generated during development by cognitive and other behavioral control
processes operating on environmental input, then that feature is said to have evolved
ontogenetically.
The distinction between phylogenetic and ontogenetic sources of adaptive change is not
meant to mimic the “nature-nurture” dichotomy. The four routes framework acknowledges that
genetic and developmental processes produce cognitive mechanisms. Not all developmental
changes in behavior are examples of ontogenetic evolution. Ontogenetic evolution is not when
systematic, experience-based changes to cognitive processes occur with no effect on
reproductive fitness.
Changes to the input to a cognitive mechanism involve changes in the identity or
environmental domain from which a cognitive process receives information, or changes in the
amount of information received. A change in the mechanism of a cognitive process alters the
way the information is processed, or the way the mechanism operates.
When natural selection alters the input to a cognitive mechanism by changing an
upstream non-cognitive process, phylogenetic inflection has occurred. Filial imprinting and
spatial memory in food-storing birds serve as examples of phenomena that have been historically
understood as having evolved through phylogenetic construction. Yet years of interdisciplinary
research has not provided strong evidence that distinct mechanisms are involved in either case.
When the interaction between a cognitive mechanism and its environment during
development (developmental selection) produces adaptive change to the rules and
representations (mechanisms) of a cognitive process, ontogenetic construction has occurred. It
has been argued that facial recognition and theory of mind evolved through phylogenetic
construction. These phenomena, however, are just as likely to have evolved through ontogenetic
construction.
It is known that cognitive mechanisms involved in facial recognition are distinct from
those involved in other object recognition. The question is whether they became distinct through
phylogenetic or ontogenetic construction. Figure 2 illustrates an alternative to the phylogenetic
construction hypothesis. If phylogenetic construction provided domain-general object
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recognition mechanisms, then it is possible that phylogenetic inflection changed the input into
such mechanisms, possibly by increasing the amount of input. Such a “wealth of the stimulus,”
or experience with faces, could contribute to the process of ontogenetic construction, which
generates face recognition mechanisms distinct from those produced by natural selection. This
hypothesis does not exclude phylogenetic construction—species-level natural selection—from
the process, but there is no positive evidence to suggest that the phylogenetic hypothesis is
stronger than the ontogenetic hypothesis.
Figure 2. Face recognition as a result of phylogenetic inflection and ontogenetic construction
Natural Selection generates
domain-general
object recognition
mechanisms
Ontogenetic
Construction:
“wealth of stimulus”
(aka experience with
faces)
distinctive
face
recognition
mechanisms
Phylogenetic Inflection:
early input to the mechanisms
responsible for object
recognition has been biased
(through natural selection)
toward faces
Another cognitive process that is commonly understood as having evolved out of
phylogenetic construction is the theory of mind. From the phylogenetic construction hypothesis
it follows that there exist distinctive mechanisms that govern the representation of mental
representations—metarepresentation—and that this capacity has been shaped by natural selection
for its adaptive role in complex social interactions. The ontogenetic construction hypothesis
proposes that the ability to represent mental representations arises out of experience with one’s
own behavior and that of others, including mentalistic language of those who have fully
developed a theory of mind. For example, research shows that there is a sharp increase in
mothers’ references to their own mental states while talking to their infants just before children
begin to pass false-belief tests, which demonstrate an understanding that beliefs can be false and
therefore suggests metarepresentation. Also, the development of a theory if mind is delayed in
deaf children; these results concur with predictions of the ontogenetic construction hypothesis,
which highlights developmental selection as the source of adaptive change.
When the interaction between a cognitive system and its environment during
development adaptively alters input to a cognitive mechanism without changing the mechanism
itself, ontogenetic inflection has occurred. An example is imitation, or the learning and
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performing of a motor pattern or body movement by observing a model. The phylogenetic
construction hypothesis would assert that the mechanisms that govern imitation and other forms
of motor learning are distinct from each other. On the other hand, the ontogenetic inflection
hypothesis suggests that the same mechanisms operate both imitation and practice-based motor
learning, but that the input into those mechanisms is atypical. In the case of imitation, the body
movements being learned are observed, not executed or learned through some other guidance.
Thus, for imitation the input into the mechanism is distinct from the input for other forms of
motor-learning, but the mechanism itself does not change. This alteration in input occurs through
developmental experience with movements that are concurrently observed in and executed by a
model, and therefore has its source in ontogeny.
The four routes framework is not a theory; it does not make testable predictions but
serves as a scheme for organizing research questions. Rather than merely asking whether or not
adaptive specialization has occurred, the four routes framework allows evolutionary
psychologists to ask questions about the source and locus of the adaptive change. The framework
also does not assume that all cognitive mechanisms evolved through phylogenetic construction,
or species-level natural selection, as it is commonly understood. By making possible the
identification of other types of adaptive specialization, this framework opens channels of
communication between various theoretical approaches to evolutionary psychology.
Outline of:
Heyes, C. (2003). Four routes of cognitive evolution. Psychological Review, 110, 713-727.
Outline by Marian Alonso and Paulina Murrietta
I. Introduction
A. Problems with Human Nativist Evolutionary Psychology (HNEP)
1. examples of adaptive specialization could be interpreted as modular whether or
not data actually support such a claim and all of evolutionary psychology could
thus be seen as flawed
2. doesn’t distinguish between cognitive and non-cognitive mechanisms
3. assumes that natural selection is the only source of adaptive change
II. Four routes of cognitive evolution
A. Describes four ways in which cognitive processes can change such that adaptive
behavior results from the change
B. Acknowledges the existence of cognitive modules and allows for the identification of
other types of adaptive specialization
III. Organization of the framework (see Figure 1 in summary)
A. Two sources of adaptive change
1. Natural selection: gene-based evolution
a. phylogenetic, or species-level, adaptive change
2. Developmental selection: the interaction between a developing organism and
its environment
b. ontogenetic, or individual-level, adaptive change
B. Two loci of adaptive change
1. Mechanism: the cognitive mechanism itself
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a. construction, or a change in the mechanism that processes information
2. Input: the range or type of information processed by the cognitive mechanism
a. inflection, or a change in the input to a cognitive mechanism
IV. Phylogenetic Construction
A. The dominant interpretation of adaptive change; evolution by natural selection as it is
currently understood
1. this paper will examine phenomena that are understood as having evolved
through phylogenetic construction and suggest alternative hypotheses for
explaining the evolution of such phenomena
V. Phylogenetic Inflection
A. When natural selection alters the input to a cognitive mechanism by changing an
upstream non-cognitive process
1. examples include filial imprinting and spatial memory in food-storing birds
VI. Ontogenetic Construction
A. When developmental selection produces adaptive change to the rules and mechanisms
of a cognitive process
1. examples include facial recognition (see Figure 2 in summary) and theory of
mind
VII. Ontogenetic Inflection
A. When the interaction between a cognitive system and its environment during
development adaptively alters input to a cognitive mechanism without changing the
mechanism itself
1. an example is imitation, or the learning and performing of a motor pattern or
body movement by observing a model
VIII. Conclusion
A. Four routes framework is not a theory
1. rather, it organizes research questions
B. How the framework serves evolutionary psychologists
1. instead of asking whether or not adaptive change has occurred, the framework
attempts to identify the source and locus of adaptive change
2. this framework is compatible with various theoretical approaches to
evolutionary psychology (nativist, constructionist, etc.) and thus allows for
communication between those approaches
Test Questions
Multiple Choice
1. ___________ is an alternative hypothesis to explain the development of facial recognition.
a. Phylogenetic Construction
b. Phylogenetic Inflection
c. Ontogenetic Construction
d. Ontogenetic Inflection
2. Which of the following is a problem with Human Nativist Evolutionary Psychology?
a. examples of adaptive specialization could be interpreted as modular whether or
not data actually support such a claim and all of evolutionary psychology could
thus be seen as flawed
Cognitive Evolution
b. doesn’t distinguish between cognitive and non-cognitive mechanisms
c. assumes that natural selection is the only source of adaptive change
d. all of the above
3. When the source of adaptive change is developmental selection and the locus of adaptive
change is the cognitive mechanism then ___________ has occurred.
a. Phylogenetic Construction
b. Phylogenetic Inflection
c. Ontogenetic Construction
d. Ontogenetic Inflection
True or False
4. The Four Routes Framework is a theory of adaptive change occurs.
5. Heyes suggests that the phylogenetic construction hypothesis is overused to explain the
evolution cognition.
6. Phylogenetic inflection is when the interaction between a cognitive system and its
environment during development adaptively alters input to a cognitive mechanism without
changing the mechanism itself.
Answer Key
1. c. Ontogenetic Construction
2. d. all of the above
3. c. Ontogenetic Construction
4. false
5. true
6. false
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