1. Nature nurture
What is the Nobel savage myth?
'wild human' Who has not been corrupted by civilisation and therefore symbolises humanities innate goodness
What is artificial and natural selection?
Artificial: - choose who reproduces - can soon make new animals we find useful, scientifically interesting or cute Natural selection: - nature does the chosen Are the same process - natural selection as more time Selection pressures filter genes
Weaknesses of the evolutionary theory?
Reductionism: - explains rich tapestry of human behaviour in a small collection of mental mechanisms which arose due to our hunter gatherer past - different levels of explanation are needed for different levels of organisation - ignores other influences Evolutionary theory may help identify the function of a trait, they do not specify the relevant causal mechanisms in sufficient detail Proximate theories need to look at specific factors Thought of as being guilty of telling 'just so' stories
What is the twin method predicated on? (limitation)
The equal environment assumption (Joseph, 2015) - EEA says MZ and DZ twins share the same environment - but what if MZ twins have a more similar environment than DZ twins - if they look similar might be treated in the same way Could lead to an overestimation of genetic contribution to individual differences and cause people to have an excessively genetic model of psychiatric illness
What is nature nurture like in artificial intelligence?
The human brain project got a 1 billion Euro grant One goal is to develop a deep learning neuronal network that learns to recognise objects and functions in a way similar to real neurobiological systems The challenge is a complex one, as it has so many cells, each with so many connections (synapses) Current computer power is insufficient to model an entire human brain at this level of interconnectedness
Modern society?
A lot is about conning money out of our Stone Age selves with mirages and fictions - soap operas probably waste thousands of house bc of our innate obsession with tribal scandal and hierarchy's We shouldn't be surprised if modern behaviour seems unhealthy and counterproductive - used to be adaptive, now its not in our new environment
What are the political implications?
Ev psych insists that humans share a common ancestor with all animals and that we were not put here on earth for a reason by an intelligent design - this is a radical attack on most religious beliefs systems and the power and authority of religious institutions Ev psych challenges the Nobel savage myth - unlikely that humans were always happy and peaceful before modern sins - murder rate in modern hunter gatherer groups is often higher than any inner city - archeology shows abundant evidence for violence before agricultural and industrial development (Pinker, 2002)
How do genotypes control phenotypes?
Genotype - set of genes in our DNA Phenotype - the physical body which grows under genetic control and environmental influence Genes make it to the next generation when they code a phenotype which is good at surviving and reproducing under current environmental conditions Genes that dont make it code a phenotype trait which is bad at surviving and reproducing under current environmental conditions
Whats happening now with AI?
Google and Facebook are investing £billions in neural network inspired machine learning algorithms, and these are now used in everyday products like Alexa. Facebook is learning about you when you use it, and giving you a personalized, bespoke regime of adverts. CCTV cameras are linked to computers that recognize individual faces. Google's 'Deep Mind' network beat the human world champion at the game of Go in 2016 (Go is much harder for computers than Chess). This is probably the best example of psychology being applied to the real world.
What are the limits of the neural network models?
Lake et al (2017) continued the useful tradition of looking at similarities and difference between Human and artificial intelligence Unlike neural networks, humans seem to learn and generalise very quickly in a common sense way, without the need for massive training Many species-typical cognitive capacities are indeed genetically hardwired, and vulgar, uncritical (mis)readings of connectionism might understate this important point. Brains are programmed to learn some things much better than other things, and species differ dramatically in the kinds of things they can learn at all. To understand why, we have to look at evolution and how genes build brains adapted to an ecological niche.
Experience Maquire et al (2000)
London taxi drivers had a larger hippocampus the longer they had been driving
What was nature nurture like in the 20th century?
Lorenz's Ethology documented instinctive behaviors in animals. Innate releasers triggered fixed action patterns. E.g. geese will attach to the first moving thing they see and treat it as a mother. Baby Seagulls will peck any red spot. Instincts are often tricked by man-made objects, and this is often a conservation problem Skinner's Behaviorism documented laws of animal training through reinforcement. Behavior can be learned and remolded with the right reinforcement schedules. Improving society is all about training people, but not blaming people.
Further limitation of twin studies?
MZ twins are not always identical even in utero eg if they have different blood flow. Different methods of calculating concordance, pairwise or probandwise, gives different estimates.
What are Tooby and Cosmies (2005) and Pinker (2002)'s view?
Think these worries bias scientific judgment - even if we dont like political implications of evolutionary psychology, says nothing about its scientific validity
ESSAY Q
This lecture is relevant for the essay 'How does modern research balance nature and nurture positions? (2000 words excluding reference list) Conceptual foundations of evolutionary psychology Tooby and Cosmides (2005) The book 'the blank slate' by pinker (2002) elaborates on these ideas
Wolf et al (2017)
Wolf et al (2017) twin study of 3,318 male pairs. Found heritability of PTSD was 49% and 25% resilience. When correlated together 59% of the correlation was attributable to a single genetic factor. Generali et al (2018) - found that genes play a role in developing autoimmune and autoinflammatory diseases eg arthritis.
Ev psychology Tooby and Cosmides (1992)
Based on the premise that cognition and behaviour are both the result of millions of years of evolution Processes of natural selection and sexual selection have determined species cognitive architecture Understood by considering the evolutionary environment and the challenges that influenced its evolution
What do evolutionary psychologists propose?
Big contrast! Proposes the brain is pre-organised by genes so it comes 'out the box' full of computational mechanisms to guide adaptive behaviour that maximised the number of offspring
How does understanding biology make the SSSM. less tenable?
- At a certain level of abstraction, every species has a universal, species-typical evolved architecture. - This is not to say there is no biochemical individuality, especially in quantitative features. - Yet, all have the same basic functional design - when humans are described from the point of view of their complex adaptations, differences tend to disappear, and a universal architecture emerges
What are the 3 aims?
1. To cultivate aesthetic appreciation of science and philosophy. 2. To cultivate a sense of puzzlement about the everyday mental life. 3. To have an informed opinion about major controversies.
The connectionism model
1990's connectionist models could (for example) learn to recognize faces and discriminate whether new faces were male or female. Synaptic weights start random, and the network says 'male' or 'female' at random. During training, the network is given Yes/No feedback, which reweights synapses using a simple 'backprop' rule. The trained network can classify new faces accurately. The 80 point activation vectors in hidden layer are interesting (each face is point in an 80d hyperspace). Similar faces generate similar activation vectors, and we get little clouds in the hyperspace (with a prototype in the middle).
Evolutionary psychology
About the origin of life Explains how species change over time Demonstrates humans descended from monkeys It is the strongest and most intelligent of the species that survives
So what happened?
According to modern Nature advocates genes control growth of many innate gadgets in the brain, which serve adaptive functions. According to modern nurture advocates, neural networks exposed to a regular environment can learn to do adaptive functions. Of course, the geographical divide is not that strong in reality, but it's a shorthand way of remembering the ideas. Rationalism and Empiricism in old European philosophy are just earlier versions of nature and nurture positions respectively.
What is adaptive behaviour?
Adaptive behaviour is behaviour that tended to promote the net lifetime reproduction of the individual or that individual's genetic relatives. - By promoting the replication of the genes that built them, circuits that—systematically and over many generations—cause adaptive behavior become incorporated into a species' neural design. Behavior that undermines the reproduction of the individual removes the circuits causing those behaviours from the species. - maladaptive Many feelings and behaviors make sense in the light of evolution. Many adaptations are not so obvious.
James (1890) description of human instincts
Black things , and especially dark places , holes, caverns, etc., arouse a peculiarly gruesome fear. - explained after a fashion by ancestral experience. The fact of such instinctive fear is easily explicable when we consider that our savage ancestors through innumerable generations were accustomed to meet with dangerous beasts in caverns, especially bears, and were for the most part attacked by such beasts during the night and in the woods, and that thus an inseparable association between the perceptions of darkness of caverns and woods, and fear took place, and was inherited.
What are twin studies?
By comparing MZ and DZ twins we can estimate genetic influence - if MZ twins are more similar than DZ, there is a genetic influence For nearly every psychological phenotype measured, MZ twins are more similar than DZ twins (Bouchard, 2004)
Polderman et al. (2015)
Conducted a MA of virtually all twin studied in the past 50 years Results provide compelling evidence that all human traits are heritable, not one trait had a weighted heritability estimate of 0 The relative influences of genes and environment are not randomly distributed across all trains but cluster in functional domains 2/3 of traits show a pattern of MZ and DZ correlations that is consistent with a simple model whereby trait resemblance is solely due to additive genetic variation Means there is nothing wrong with basic interpretation of twin studies
How do new species arise?
From reproductive isolation, followed by genetic drift and exposure to different selection pressures When two pops are separated for a long time eg marooned on an island, they genetically drift into different directions If reintroduced they can no longer reproduce, so they are different species Homo sapiens are relatively new, only around for around 100,000 years - probably had common ancestors with chimps and bonobos For most of our history we have lived in small bands of hunter gatherers, with many close relations in the same tribe Often evolutionary psychology references selection pressures faced by hunter gatherers
What was nature nurture like in the 21st century?
East vs West coast researchers in America On the East coast, 'Rationalist' researchers originally influenced by Chomsky's grammar and criticisms of behaviourism propose many innate modules or gadgets in the brain, each like a little organ, doing a precise function (Fordor's 1983 book 'modularity and mind' that promoted this view strongly). On the West Coast, 'Empiricist' researchers influenced by Hebb's connectionism emphasize self-organizing properties of neural networks. Artificial neural networks can be learn to do all kinds of surprisingly cognitive things, without being specifically programmed to do them.
What are the two profound truths about life?
Every single one of your ancestors survived long enough to reproduce - there were many others that failed, you are from an unbroken line of winning biological designs All other animals and plants are your cousins, and you have a common ancestor with all of them - even trees, slugs and bacteria
What are the other political implications?
Evolutionary psychology claims that the 'ungodly' features like lust, aggression, gossip and sneaky competition are just as natural as 'godly' features like generosity, honesty, sympathy or guilt. - Human minds have many adaptations. These adaptations all helped our ancestors meet recurring challenges which statistically influenced their chances of reproduction. - Its meaningless to say we are 'fundamentally' good or bad. This is a common sense position as well, but it undermines certain dogmas in religion and politics. The chapter Why nice guys sometimes finish first (Dawkins, 1982) is a good remedy for any extreme despair of euphoria about evolution and human nature. Cooperation and reciprocal altruism evolved too.
But what about this fuss?
Evolutionary psychology claims we all have the same brains, with a lot of rich, detailed, inherited structure but with only relatively minor modifications between people. - this is an egalitarian position, it still says everyone is about the same Old fashioned prejudices tantamount to saying rich white men were a better species and thats not true
What is the standard social science model? (SSSM)
Evolutionary psychology is not a direct enemy of connectionism, but is supposed to be very different to the SSSM (Ev contrasts with SSSM) SSSM proposes that the mind is a blank state like a computer with no apps Organisation flows from the world into the brain, the brain isn't pre-arranged into adaptive models
Sauter et al. (2010)
Humans use a range of different cues to communicate to others how they feel, including facial, vocal, and gestural signals. Examined the recognition of nonverbal emotional vocalisations, such as screams and laughs, across two dramatically different cultural groups. Western participants were compared to individuals from remote, culturally isolated Namibian villages. Vocalisations communicating the so-called "basic emotions" (anger, disgust, fear, joy, sadness, and surprise) were bidirectionally recognised. In contrast, a set of additional emotions was only recognized within, but not across, cultural boundaries. Our findings indicate that a number of primarily negative emotions have vocalisations that can be recognised across cultures, while most positive emotions are communicated with culture-specific signals.
Behaviourism?
Is a blank slate model from psychology - connectionism can sometimes drift too far towards blank-statism according to Pinker but its not so fundamentally flawed Sociology and various commentaries on education, art and culture assume blank state
How do society and culture affect the parameters of a universal design?
Only seem to make a small change - we all have language, society sets the details, - we all have morality, society sets the details BUT nobody has magnetic receptors for feeling the position of the magnetic north pole (some birds do)
What is the political opposition to evolutionary psychology?
Powerful white males have historically justified and consolidated their privileges by claiming other social groups are genetically inferior (rather than culturally disadvantages) - women, blacks and poor are some of the disadvantaged SSSM has been part of a cultural struggle against injustice - blank state story says we are all equal, consistent with many peoples political ideology and values - academics can be squeamish to the idea of evolutionary psychology BUT desire for politics shouldn't make us blind to the limits of the SSSM - biological absurdity of the claims humans are a blank slate
A modern nurture-ish position?
Says the brain is like a big neural network Only a few basic things are innate (synaptic re-weighting rules and nerves) Feedback from the environment just keeps adjusting the synapses Intelligence emerges in the self organising system through exposure to a regular world - different environments give different abilities
What is nature nurture in individual differences?
Some people are impulsive, some are cautious, is that bc we are exposed to different environments or because they have different genes? Males and females tend to be a bit difficult, is it bc they socialise differently, or different genes? This debate gets hot headed and goes round in circles - twin studies can help by putting some empirical facts on the table
What is the problem with heritability?
Stats dont tell us pure facts about biology or brain plasticity - tell us about genetic influences on whatever individual differences that exist in a sample Homogenous environment (the same) - heritability estimates = 1 Different environments - heritability estimate = 0 H2 is higher if absolute individual variability is lower because of similar environments (Johnson et al. 2010). Some people think heritability statistics are nearly worthless, and potentially misleading in mental health research
Tooby and Cosmides (2005) big claim...
THE THEORY OF evolution by natural selection has revolutionary implications for understanding the design of the human mind and brain, as Darwin himself was the first to recognize (Darwin, 1859).... Yet, nearly a century and a half after The Origin of Species was published, the psychological, social, and behavioral sciences remain largely untouched by these implications, and many of these disciplines continue to be founded on assumptions evolutionarily informed researchers know to be false (Pinker, 2002; Tooby & Cosmides, 1992)"
What did Tooby and Cosmides (2005) claim?
That the apps in your brain are content and domain specific - apps on a computer deal with one type of content and perform certain operations on that content - more apps means the clever the computer - more specialisation = more intelligence Argue the brain is not just generally smart in an unbounded way, nor does it have a few basic rules for learning - the brain has many content and domain specific apps - they are being east coast here
SO what do they think?
The mind is best understood at the computational model - the brain performs computational operations on internal representations to produce adaptive behaviour Each representation is a physical state, which codes some info, and can be read by other parts of the system - this representational computational model is comparable with neuroscience To understand the mind we can use the metaphor of a computer with many programs or apps (without claiming the mind is anything like digital computers)
What would Pinker, Dawkins, Tooby and Cosmides argue?
There is absolutely nothing in evolutionary science that supports eugenics, racism or sexual discrimination - there is nothing in evolutionary psychology that says human nature is ultimately selfish and dishonest Selfish Geens do not produce uniformly selfish animals - we are reciprocal altruists by default There is nothing to say that institutions and economies work best when they are ruthless and Darwanian
What are the criticisms of the 21st century debate?
Typically less dogmatic and more well informed Its agreed that the truth is somewhere between extreme nature/nurture, but the balance, interactions and mechanisms remain unclear Nature: - we understand a lot more about how the brain learns and adjust a result of exposure to the environment - artificial intelligence has helped here (attracts a lot of money and is probably the future of psychology
Does it work?
Unlike earlier AI, these connectionist models are quite brain-like (Churchland, 1998). The philosophers Paul and Patricia Churchland are enthusiastic about connectionism. This famous 'Deep Convolution Network' (called AlexNet) can successfully recognize thousands of objects and its hidden layers resemble ascending visual hierarchy (Krigleskorte, 2015).
What is the heritability statistic?
Varies between 0 and 1 Tells us how much measured variation in a phenotypic trait is explained by variation in genes MZ twins should be more similar Siblings should be more similar than unrelated people - parents more similar to their own children than other children About 70 to 95% of variation in height is inherited. About 20 to 50% of variation in personality is inherited About 50% to 80% of variation in intelligence is inherited.
McCulloch and Pitts (1943) and Hebb (1948)
Were early pioneers who recognised that synaptic plasticity was at the heart of learning They started playing with artificial neural networks - Freud has a similar idea before he got into psychoanalysis By the 1980s this was called connectionism
What have people been put off by when researching evolution?
What they assume are the political and moral consequences of accepting a theory, for example: - there is no god and thus no moral truth - people are fundamentally selfish brutes - so there is no point trying to be good - feminism is misguided because men and women are genetically different - current elites are genetically superior - racism is valid or inevitable
TIP
When thinking about innate and learned mental features, it is often instructive to focus on big cognitive differences between species not the little cognitive differences between individual animals
