1
Q
What is the Nature-Nurture debate?
A
- The debate of “How much of an individual’s behaviour is due to their genotype and how much is due to their environment?”
2
Q
What did Plato and Aristotle say about the Nature-Nurture debate?
A
Plato -> Nativism; Some knowledge and abilities are innate
Aristotle -> Philosophical empiricism; Knowledge is acquired only through experience
3
Q
What is the “conclusion” of the Nature-Nurture debate?
A
A person’s behaviour is the product of both their genotype and environment. What is important for us to study is how they interact together to influence behaviour.
4
Q
Explain the “Nature” side of the Nature-Nurture debate
A
- Traits are innate; Inherited from parents
- Formalised in Darwin’s theory of evolution via natural selection
- Combined with discovery of genetics to form the modern synthesis
5
Q
What were the beliefs on evolution before Darwin?
A
- Species fixity; The idea that each species is fixed in their physical form which does not change over time
- Philosophers had always questioned this belief on the elements of nature and the origins of life
- Titus Lucretius Carus (99-55BC) wrote about natural selection -> “Individuals best suited to their environment would survive while others would be elimintated”
- Darwin then used the word evolution in his 1871 text, as the process of developing by gradual changes
6
Q
Significant Precursors to Darwin (17th to 18th century): Pierre Maupertuis
A
- Suggested that particles from both mother and father are responsible for child’s attributes
- Nature side of the debate
7
Q
Significant Precursors to Darwin (18th century): George-Louis Leclerc, Comte de Buffon
A
- Some considered him the father of evolutionism
- First to discuss a large number of evolutionary problems
- ex. origin of the Earth, issue of extinction, common ancestry, comparative anatomy, etc.
8
Q
Significant Precursors to Darwin (18th century): Denis Diderot
A
- Speculated on the origins of life without divine intervention
- Presented ideas for survival by superior adaptation and was arrested and imprisoned for three months
9
Q
What delayed Darwin’s work to be published?
A
- Darwin delayed the release of his essay on evolutionary ideas because of The Anti-Jacobin, a newspaper which also mocked Erasmus Darwin’ earlier work
- This satire would later be used to criticize and mock Charles Darwin
10
Q
Significant Precursors to Darwin: Lamarck’s theories
A
- Lamarck’s theories of evolution were described in Philosophie zoologique (1809)
- Lamarckism is a theory of the inheritance of acquired traits (phenotypes)
- Attempted to explain how the environment in a current generation can impact heritability, and argued that the traits that develop in a person could be inherited by offspring
- Theory centres around use and disuse (The traits/characteristics/muscles that are used more during one’s lifetime are the ones that will be passed down to the next generation)
- Species would change over time because of a build up of these inherited changes
11
Q
What inspired Darwin to study evolution?
A
- Travelled as an unpaid naturalist
- Found fossils of extinct species in Argentine
- Saw that living creatures are well-adjusted for living in their natural environment
- Set out to explain why species change and why those changes are so well-designed
12
Q
Describe Darwin’s Journal of Researches (1845)
A
- Saw the importance of the environment and the struggle for existence in shaping adaptative responses
- Variation is not directed towards improved adaptation; evolution has no goal in mind -> It is undirected (selection pressures)
13
Q
What did Darwin say about natural selection?
A
- Change in the form and behaviour of organisms within a population and between generations
- Change happens so slowly that it (usually) cannot be perceived
- Changes/variations in attributes occur most often through the random process of mutation
- If the attribute is an advantage to survival -> It is adaptative and is selected -> Passed onto next generation and increase in frequency
- If the attribute is disadvantageous to survival -> Survival chances of that individual is reduced -> Frequency decreases
14
Q
What did Alfred Russel Wallace do in the study of evolution?
A
- Independently arrived at a similar idea to Darwin’s abstract, and sent a letter to Darwin
- However, Wallace did not think natural selection applied to human evolution, which he argued required divine intervention
15
Q
What kind of response did Darwin’s work receive?
A
- Evolution was controversial but somewhat accepted by the scientific community
*Inspired William James (1980) to develop functionalism - But natural selection was criticised because it required a satisfactory theory of heredity
*Natural selection was said to have no supporting mechanism
*Darwin suggested pangenesis, and somewhat accepted Lamarckism
*August Weismann put forth strong arguments disproving pangenesis and Lamarckism, and put forward his theory of “germ plasm” inheritance
16
Q
What were the key points in the study of evolution during the 20th century?
A
1909 - Wilhelm Johannsen coined the term “genes”
1913 - Thomas Hunt Morgan located the genes on the chromosomes (with which the infamous image of beads on a string emerged)
1930-32 - RA Fisher, JBS Haldene and S Wright independently published their own synthesis, showing that natural selection could operate with mendelian genetics
17
Q
What were Gregor Mendel’s contributions to the study of evolution in the 19th century?
A
- Performed meticulous experiments and statistical analysis by cross-breeding variants of peas
- First to lay down the mathematics of genetics and heritability, and presented them in lectures
18
Q
What were the key points of evolution studies, after Darwin?
A
- Dobzhansky’s influential works with fruit flies and Ford’s with moths
- 1942: Julian Huxley popularized the synthesis in Evolution
- 1942: Speciation by Ernst Mayr
- 1944: Simpson demonstrated that the fossil record was compatible with the synthesis
- 1947: Experts from all areas of biology gathered and came to the agreement that evolution occurs via natural selection and inheritance occurred via Mendelian principles
- In the 1970s: Lorenz & Titenbergen inspired the emergence of evolutionary psychology through their work on complex animal behaviours (spontaneous/natural, not learned)
19
Q
What were the other key additions to the theory of evolution?
A
- Sexual selection
- Kin selection
- Group selection vs Selfish gene (Dawkins)
- Natural selection is not the only mechanism of evolution but it is the only mechanism for adaptation
- Dual-inheritance theory (gene-culture coevolution)
20
Q
Explain the “Nurture” side of the Nature-Nurture debate
A
- Individuals are born as blank slates
- Traits are a result of experience and learning
- Formalised by objective psychology and behaviourism approaches
21
Q
Describe Ivan Pavlov’s classical conditioning
A
- Behaviour, whether learned or innate, was reflexive
- Studied internal reflexes (ex. salivation, digestion)
- Conditioned stimuli act as signals announcing the occurrence of biological significant events
- Described the link formed between unconditioned and conditioned stimuli as associative learning
- Found language as a series of conditioned reflexes involving words
22
Q
Vladimir Bechterev on objective psychology
A
- Opened the first Russian experimental psychology lab (19th century)
- Competitor of Pavlov -> Independently studied his own objective approach to studying psychology through association reflexes and the behaviours produced
- Laid the groundwork on neuroscience
- Focused on the relationship between environmental stimulation and behaviour
- Explored behavioural responses as a result of physical, biological and social conditions
23
Q
What did Vladimir Bechretev criticise on others’ works?
A
- For Pavlov,
*Pavlov’s experiments required surgery and therefore didn’t explore natural phenomenon
*Pavlov’s procedure couldn’t easily be used on humans
*Animals and humans will be satiated by food, so poor behaviour to measure - Criticised American researchers exploring behaviourist Qs at the same time (saying that the ideals behind the study of objective behaviour originated in his laboratory)
24
Q
J. B. Watson’s Objective Psychology
A
- Says that psychology requires replicable, objective measurements of observable behaviour in controlled environments
- Goal of psychology should be to predict and control behaviour to benefit society
- Did not deny innate behaviours but also believed that environment is the most powerful influence on human psychology
25
What did J. B. Watson and Rayner-Watson say about child-rearing?
- Treat them as small adults
- Don't be as generous with mother's love
26
What were the key points of behavioural psychology in the "Nurture" side of the Nature-Nurture debate?
- John Locke states that individuals are shaped by the consequences of their experiences, via reinforcement
- Thorndike's Law of Effect (reward and punishment)
- Operant conditioning was developed in the 1930s using rat experiments
27
What were the lasting contributions of behaviour modifications?
Provides the roots for desensitization techniques and CBT today (ex. phobias, anxiety disorders, addiction and unfortunately 'treatment' of homophobia)
28
What were the lasting contributions of reinforcement and punishment (Law of Effect)?
- Explains how animals learn in their environment
- Can help explain behaviours such as addiction
- Improving social welfare (ex. reinforcement to reduce smoking)
29
What were the lasting contributions of objective psychology and behaviourism?
Paved the way for a scientific approach to psychology
30
What were the lasting contributions of Thorndike's, and later also Skinner's, contributions to educational psychology?
Broke down difficult classroom questions into smaller chunks with rewards (positive reinforcement over punishment - active learning)
31
What was the origin of the Nature-Nurture debate?
- The debate had been going as long as humans have debated why humans exist
- Francis Galton likely coined the phrase 'nature and nurture'
- Galton summarised it as (1) Nature represents what a person brings with them into the world, including its faculties of growth and mind, whilst (2) Nurture is every influence that affects this person once they enter the world, by which natural tendencies may be strengthened or reduced or wholly new ones implanted
32
Describe Francis Galton's twin study of inheritance
- Galton was credited with the first twin study used to assess the relative strength of inherited traits and the effect of the environment
- Distributed a questionnaire to around 600 pairs of twins (measuring height, skills, tastes, etc.) but received back from 94 of them
- Though credited, he did NOT actually measure this twin study
- He did not make comparisons between identical and fraternal twins -> looked at lifelong development of twins and the convergence of traits in a shared environment vs the divergence of traits in differing environments (adulhood)
33
Describe the conclusions from Francis Galton's twin study of inheritance
- Differences in experiences in adulthood did not have an effect on twins that started off very similar, and they remained so. While twins that started of as very dissimilar did not become more similar when they shared the same environment
- "Nature is far stronger than nurture" -> Affirmed his nativist and biological determinism position
34
What is heritability (h²)?
- Tells us whether variations in a population for a given trait are due to different genetics or different environments
- A population statistic and cannot be applied to a single person to explain the development of a trait
- Typically expressed between 0 to 1 (0 -> fully environmental factors, 1 -> fully genetic variation)
35
Explain the significance of twin studies in understanding heritability
- Identical (monozygotic) twins have the same genes
- Fraternal (dizygotic) twins share 50% of their genes by descent on average
- Twins may be raised together in a shared environment, or apart by adopted families
- Natural experiments can text influence of genetics and environments and indicate heritability
36
Describe the heritability & twin studies at University of Minnesota
- Over 20+ years, they studied 71 MZ pairs + 53 DZ pairs who had been raised apart AND 99 MZ pairs + 99 DZ pairs who had been raised together
- MZ twins were more similar than DZ twins regardless of whether they were raised apart or together
- Average heritability of the CPI traits was 0.46
37
What factors should be considered in twin studies and heritability?
- Humans affect the environment around them, so identical twin in 'different environments' may in fact be influencing their environments in a same way, and they then end up in more similar environments than we would assume
- Adopted twins may have more similarities in their environments due to the restrictions placed on adoptive families
38
What are the major issues of the Nature-Nurture debate?
- Programming/controlling behaviour; Heteronormativity and Skinner's utopia
- Biological determinism; Scientific racism, Eugenics and 'Racial Hygiene' laws, and compulsory sterilization
39
Explain the era of evolutionary adaptedness
- The 'era' in which modern human (homosapien) adaptations evolved
- EP assumes minds evolved to deal with tasks that were important to our survival and reproduction in evolutionary past
40
Give a brief history of the problem of human morality
- Kropotkin noted that the most successful animals seemed to be the most cooperative
- If evolution works by pittin animals against each other, then it also worked by designing them to seek mutual benefits
41
If morality/cooperation is costly, then why is it so widespread?
- Empathy observable and measurable in bird and mammals
- Capacity traceable to some reptiles (the 'lost call' performed by alligator offspring)
- Positive social emotions in primates (warm glow)
42
What theories or factors are used to trace the capacity for human morality?
- Kin selection
- Direct reciprocity
- Larger group size
- Lead to high order cooperation beyond kin and reciprocity
- Interdependence
- Competitive altruism
- Cheat detection
- Gossip
- Social emotions
- Punishment, fairness, trust, justice
43
Explain the concept of modularity of the mind (Swiss Army Knife Model of the Mind)
- Mind comprises of a set of specialised modules each designed to solve particular problems (e.g., using tools, finding mates, learning languages, etc.) (Cosmides and Tooby, 1992)
- One of these proposed modules is the 'cheater detection module'
44
Explain the modular brain (Fodor, 1983)
- Humans don't tend to reason in line with formal logic
- Illusion persists even after we are aware of it
- Our knowledge does not affect our perception because perception modules are encapsulated
- Makes for faster processing speed (think predator)
- Evidence for domain-specific modules
- Cosmides and Tooby apply this argument to other processes such as cheat detection
45
Describe the Wason Selection task
- Developed by Wason (1966) to investigate whether people test hypotheses about the world in a logical way
- Subjects are told a rule and asked how they would check if the rule has been violated or not
46
Differentiate between the Abstract rule and the Social contract
Abstract rule:
- If p occurs, then q occurs
- The task is to detect violations
Social contract:
- If you take the benefit, then you must satisfy the requirement
- The task is to detect cheats
47
What is the evidence for cheat detection?
- We are better at detecting violations of a rule when it is a social one
- This increased performance is not due to framing in non-abstract terms, framing in familiar terms, logic being activated by social framing and cultural differences
48
Key Points in Nature-Nurture and Human Prosociality
- Warm glow present in young infants (18 months)
- Visible concern for others in distress (1yo)
- Preference for cooperative characters over antisocial characters (through gaze experiments with 10mnth infants)
- Voluntary helping behaviour in a controlled environment
- Babies start off on a similar pathway irrespective of culture, then diverge in line with local cultural norms of adults (Callaghan & Corbit, 2018)
