Evolutionary Psychology
Lecturer: Mark van Vugt
Lecture 1: 05 sept 2022
Foundations of Evolutionary Psychology
Why do people do the things they do? Is there a way to explain them with the already existing
theories in the psychology field? Could we gain insights by thinking about humans as a
biological species subject to the same environmental pressures as other animals?
Evolutionary psychology is the study of human behavior, affect and cognition form an
evolutionary perspective
Using evolutionary theories to understand why the human mind works this way
and how it has been designed
In effect, it means viewing humans as part of the animal kingdom, subject to the
same laws of evolution, natural selection and more
Evolutionary psychology focuses on four key questions:
Why is the mind designed the way it is, that is what causal processes created,
fashioned or shaped the human mind into its current form?
How is the human mind designed, what ere its mechanisms or component parts and
how are they organized?
What are the functions of the component parts and their organized structure, that is
what is the mind designed to do?
How does input from current environment interact with the design of the human mind
to produce observable behavior?
Jean-Baptiste Lamarck (1744-1829) had a theory about how organisms change, in his
theory, Lamarck argued that organisms could pass on characteristics they acquired during
their lives to their offspring
The inheritance of acquired characteristics
Use and disuse of traits (e.g., muscles)
Living things evolved in a continuously upward direction through simple to more
complex forms towards human ‘perfection’
Charles Darwin (1809-1882) stated that all species of organisms arise and develop through
the natural selection of small, inherited variations that increase the individual’s ability to
compete, survive and reproduce
Biological evolution by natural selection, general evolutionary theory
When more individuals of each species are born than can survive and when there is a
recurring struggle for existence, some will have a better chance of surviving
The survival of the fittest, the strongest are naturally selected
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,Thus, differential reproductive success, brought about by the possession of heritable variants
that increase or decrease an individual’s chances of surviving and reproducing, is the ‘bottom
line’ of evolution by natural selection.
From the strong principle of inheritance, any selected variety will tend to propagate its new
and modified form. Those individuals with heritable traits better suited to the environment
will survive.
Natural selection consists of three components
Variation, for example in physical aspects like height, weight, eye color…
Inheritance, some of these variations are genetic, they are inherited
Selection, meaning that having a certain trait gives you an advantage (intelligence)
There is also individual variation in traits, some trait variations allow their bearers to better
compete for resources, if these traits are inheritable, then they are passed on from generation
to generation. The result: individuals of a species become better adapted to their
environments.
Inclusive fitness is a method of measuring evolutionary success, it is the ability of an
individual to transmit genes to the next generation, including genes shared with relatives
(William Hamilton)
A mechanism for evolution via natural selection: the gene (Gregor Mendel, 1822-1884). He
found out that there are dominant and recessive alleles.
The modern synthesis in biology and DNA discovery (1953)
Describes the fusion of Mendelian genetics with Darwinian evolution that
resulted in a unified theory of evolution
It proposed a new definition of evolution as changes in allele frequencies within
populations, thus emphasizing the genetic basis of evolution
There are two forms of sexual selection, traits that are selected because they make you more
attractive for the other sex:
Inter sexual competition, traits that are passed on because they are good at attracting
opposite sex mates, for example pretty feathers of birds
Intra sexual competition, traits that are passed on because they are good at winning
same sex competitions for mates, for example being good at competing with members
of the same sex for access to members of the opposite sex (stag fights)
Humans are the product of evolution, because they are incredibly complex and not at all
perfect, but functionally adapted to a certain environment.
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, The most complex organ of all is the human brain, it consists of the reptilian brain or the brain
stem (avoid and approach), paleo-mammalian complex for emotions (limbic system) and neo-
mammalian complex for planning (neo cortex).
What factors drove the increase in the hominid brain size?
Ecological factors, for example climate
Technology
Social factors
Cultural factors
Evolution has three products
Adaptions, inherited characteristics that are naturally selected because they helped
to solve a problem of survival or reproduction
By-products, carried along with adaptions but without function (like a belly button)
Noise, random effects, no function, like eye color or musical taste
Evolutionary is not a theory, but a fact. DNA evidence shows that all living organisms are of
common descent, there is evidence for intermediate life forms and natural selection in action.
Lecture 2: 08 sept 2022
Adaptions for Survival
History of evolutionary psychology:
Sigmund Freud, ‘sex is important’, it is the driving force of human behavior
William James, ‘we have lots of instincts, basically for everything’, we engage in
certain behaviors because they aid in survival, motivation is primarily biologically
based
Skinner’s Behaviorism, ‘anything can be learned as long as it is rewarded’
End of behaviorism? Garcia and Harlow experiments, a baby monkey was taken away
from his mom and gave it the options to choose between two substitute mothers, one
was a food dispenser and one was warm and soft and more like a mother feeling
Richard Dawkins (1976) believed that humans are nothing more than survival machines for
genes, the only reason humans exist is to pass the genes over to the next generation.
Cosmides and Tooby (1992) made assumptions about the adapted mind, the brain is a Swiss
army knife, they are known for their work in pioneering the new field of evolutionary
psychology
According to this approach, our brain is composed of highly specialized
‘applications’ to solve specific problems in the most effective way
Thus, our mind is a combination of specific areas or tools
Misunderstanding about evolutionary theory:
Human behavior is genetically determined (genetic determinism), but environments
and learning matter too
If it is evolutionary, we cannot change it, no we can shape our own future
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