Inhoud
Lecture 1 – Natural selection..................................................................................................................2
Lecture 2 – Childhood Environments......................................................................................................4
Lecture 3 – Sex Differences....................................................................................................................8
Lecture 4 - Cooperation........................................................................................................................13
Lecture 5 – Violent Behaviour..............................................................................................................17
Lecture 6 – Social norms & Culture......................................................................................................20
Lecture 7 – Pathogens & Threats..........................................................................................................24
,Lecture 1 – Natural selection
Main question: Under what condition is natural selection type of behaviour beneficial?
Contents for this lecture:
- Ultimate vs. Proximate Explanations
- Adaptive Problems
- Common Errors in Ultimate Reasoning
Ultimate vs proximate
Helping behaviour: Humans are social species. You invest time, effort, and money and take a risk in order to
benefit a different person. But why?
- To get help in return ultimate explanation (why in some conditions it can be beneficial for yourself)
- We feel better about ourself proximate (evolution does not care about our wellbeing; nice things
like feeling good, isn’t important. It is intrapsychic. However, this could after all be an adaptive
problem, feeling good makes a higher fitness and therefore contributes to our fitness. But it remains
intrapsychic so proximate)
- It will give us social status (if people look at you as a helpful person) ultimate (more status, more
resources, better fitness. It is an external effect; how others think about you)
- It feels nice to help proximate (is about how we feel, not what is evolutionary seen good for us)
- The group may benefit ultimate (special ultimate; only when there is group competition)
- Moral reason (to follow norms) proximate (we learn norms from culture, any learn processes are
proximate. We are really good at following norms, we internalised those and that is ultimate)
- Empathy proximate (intrapsychic)
- Perceived responsibility / role proximate (learning process)
Ultimate vs. proximate in an overview:
- Proximate (most common in psychology):
o How (underlying mechanism or process)?
o What causes the behaviour?
o Intrapsychic
o Genes can code for behaviour mechanism but still here and now, they aren’t always reflexes,
so still proximate.
o E.g.: neuroendocrine responses, genetic differences, emotions, personality, cognitive bias,
individual development, social learning, culture, epigenetic effects.
- Ultimate (improving fitness, caused by evolution):
o Why (function)?
o What are the fitness benefits?
o (Interpersonal) environment.
o Adaptive problems: What selection pressures favoured the proliferation of the trait over
time?
Example: Children cry a lot when seeing strangers. The crying itself is proximate, but the consequence, the
reaction of the parents is ultimate (because it is better for the fitness of the child, since the reaction of a parent
is to help the child).
In evolutionary psychology we look for ultimate explanations. What particular problem did this behaviour
solve? Chances to improve your fitness or adaptive problems (avoid to lose fitness).
All living organisms could be called ‘as successful as the others’ since we all are alive at the moment. The only
possibility to talk about more favourable features of organisms, is if you focus on one criterium within groups
of species. Example: population density.
,Adaptive problems
The brain is an evolved structure. It takes up 20% of our metabolic energy. It must be very advantageous to
have such a big brain for the cost-benefit relation. Otherwise there would be selection against us. Parts of the
neural circuitry must have had beneficial effects for our ancestors. Adaptive problem: recognizable cues we
need to be able to perceive things that show the adaptive problems, and to increase our fitness or avoid fitness
loss. Adaptive problem example: objects quickly moving towards you, need to be spotted quickly to be able to
react.
Formal definition of evolutionary psychology adaptive problems: The environment of evolutionary adaptedness
(EEA) is the ancestral environment to which a species is adapted. It is the set of selection pressures that shaped
an adaptation. The savannah is an example of this, this is where our ancestors come from and where they have
adapted to their situation and environment.
Westermarck effect: avoiding incest. What does it show us and how can we infer an adaptive problem from this
effect? The effect shows the strong natural aversion of genetic related people as produced by our
adaptiveness. But how does nature know who we are related to? Our nature knows who we are related to
because of the time spent together; presence in early childhood of those people (not a certainty that they are
related of course). It is an imprinting process; it takes place during a certain period of time within our lives.
Children who are not related, but grow up together, will not evolve attractiveness for each other. It’s a
heuristic. his is how adaptive problems work; if there are cues, the result will occur. If those around you do not
have shared genes, you will still have the same result.
Common errors in evolutionary psychology
- We have stone age minds in modern skulls; our genetics can’t keep up with the evolution (gene
coevolutionary mismatch).
- Natural selection is a mindless process; there is no intentional purpose or conscious reasoning behind
evolutionary processes.
- Article: why is there a difference between the talkativeness of men and women?
o Hormonal differences (proximate)
o Social learning (proximate)
o In ancestral times men had to be quit to hunt while women had to cook and talk with each
other (ultimate). This explanation is unfalsifiable however, since we can’t tell what men and
women were doing back then. Just-so stories (read Kipling).
o In a later study, it was found that men and women talk the same amount. You must always
look if you can verify the elements of your statement.
- Evolution is not only about adapting behaviour or a functional difference. The umbilical cords are
functional (adaptation; food and oxygen from mother to foetus). Belly buttons are by-products. These
are random effects / noise. Don’t be too eager to find the adaptive function. Only certain behaviours
in certain conditions are beneficial evolutionary seen.
, Lecture 2 – Childhood Environments
Overview of this course
Explanations for social behaviour about adaptive problems: Childhood Environments (lecture 2), Sex
Differences, Sociality, Group Conflict, Culture, Pathogens
LHT
Societal consequences
Reminder: adaptive problem opportunity to increase your fitness or avoid fitness loss.
Life History Theory
This weeks paper says that different socialisation processes can occur, depending on:
- The child rearing
- The environment the children grow up in
- Social bonding
- Parental presence
The Life History theory of socialisation and the more mainstream theory (like Attachment theory) are quite
alike, but the key distinction is that the evolutionary theory (attachment theory, from this weeks paper) focuses
on the parental effects, child rearing, and maturity. The life history theory is broader.
Having a securely attached relationship is more beneficial for the well-being, but it does not matter for
reproduction rates. Optimizing the reproductive output, considering the condition your growing up in, is what’s
important for evolution. So adaptive strategies are facultative (context-dependent). Conclusion: adaptive
behaviour does not have to be beneficial for the individuals’ well-being and is dependent of its context.
The definition of LHT is: theoretical framework that states that organisms calibrate their development in a way
that promotes survival and reproduction. It addresses how and when individuals and/or species should allocate
(limited) energy to somatic development and/or reproduction.
Mouse: Elephant:
Dimensions that environment differ on:
Harshness: rate at which external conditions cause disability and death (for human environments,
harshness can be predicted by scarcity of money and other resources, society, climate/nature etc.). In
