Evolution and IntelligencePSYCHOLOGY

What is evolutionary psychology?oIt focuses on how human beings came to be who we are today

oTooby and Cosmides (1992) define evolutionary psychology as informed by the fact that the inherited structure of the human mind is the product of evolutionary processes (!)oThey claim this can explain contemporary behaviour.oIt seeks a FUNCTIONAL EXPLANATION of human behaviour – one that focuses on origins e.g. why a behaviour has evolved.

The Elements of Evolution – Genetic Transmission and DiversityoGenetic Transmission and Diversity

oNatural Selection

oSexual selection

DNAoWhen life first appeared on earth, the structure of DNA was pretty common to all life forms.oOver long periods of time, DNA underwent subtle changes and different species emerged.oThe shorter the time lapse since one species has split in two, the closer in structure their DNA will be.oSince the structure of DNA evolves at a consistent rate, we can work out mathematically when two species diverged.

But what about God? As Richard Dawkins,states–“natural selection is the blind watchmaker, blind because it does not see ahead, does not plan consequences, has no purpose in view. Yet the living results of natural selection overwhelmingly impress us with the appearance of design as if by a master watchmaker, impress us with the illusion of design and planning”

(Dawkins, 1986, The Blind Watchmaker

Other ideas Creationism suggests that we are all made by a god. Evolution does not exist, regardless of the evidence. Any evidence that does exist is merely there to show God.

Humans are made in God’s image. Adam and Eve were the first humans and we are all their descendants

The evolutionary origins of the human mindoWhy are we so evolved? We have complex technology, social lives, languages and complex cultures. Why do only humans have this?oMan as Tool Maker was proposed by Oakley in 1949. He said when our hands were free to make tools when we first walked upright, we changed the way we thought.oJane Goodall (1971) found that chimps in the Gombe Stream area of Tanzania also use tools and make them but they have not developed human complexity.

Evolution of the human brain

Around 300 million years ago reptiles evolved on earth Mammals and humans followed much later

Structure of human brain bears witness to this history

There are arguably 3 interconnecting ‘brains’ which each have particular functions:- The human brain consists of:

- Reptilian brain- Mammalian brain- Neocortex [higher human brain]

Each part has different functions & represent what was important to each species

Reptilian brain Functions based on survival

Deepest, most ancient part, largely unchanged by evolution

We share this part with all vertebrates

Activates instinctive behaviour related to survival and controls essential bodily functions required for sustaining life:-

◦ Hunger, digestion/elimination◦ Breathing, circulation, temperature◦ Movement, posture and balance, territorial instincts◦ Fight and flight

Mammilian brain Social behaviour e.g. care & nurturance, playfulness, bonding

Almost the same chemical systems & structure as other mammals, e.g. chimps

Triggers strong emotions that need to be managed well be the rational brain

Also helps to control primitive fight or flight impulses

This part of the brain activates:-◦ Rage, fear, separation distress◦ Caring and nurturing, social bonding◦ Playfulness◦ Explorative urge◦ Lust in adults

Higher brain Frontal lobes are much larger allowing us to think more deeply than other animals - A chimp has small frontal lobes so it thinks mainly in the present

Human = frontal lobes are associated with higher level thinking and allow us to:-

◦ imagine & be creative◦ reason & reflect◦ solve problems◦ be self aware, show kindness, empathy and concern◦ to some extent helps us with aspects of speech◦ also contains the motor cortex – this controls voluntary movement

Newest part of the brain [frontal lobes or cortex] amounts to 85% of total brain mass

Each brain is connected to the other via a massive network of nerves

How the brain grewoHominids (earliest human relative) had brain more than half the size of ours

oHomoerectus: the brain was still small in 1st upright man 1.5 mill years ago

oHomosapiens: 200,000 years ago brain grew

Humans began painting, making jewellery & ornaments,

adopting religion but it still took a long time for humans to

develop the capacity for sophisticated thinking we enjoy today

Jerison (1973) Encephalization quotient

Brain size is plotted against body size

- Above line = relatively larger brain than expected

-On line = average brain size

-Below line = relatively smaller brain

Brain size is taken to infer intelligence

‘Encephalization quotient’= actual size of mammals brain divided by that expected for a typical mammal of its body size

IntelligenceoHow do we measure intelligence today?

oIs it reliable or valid?

oNo agreed definition of intelligence therefore can be difficult to measure

Goff (2000)oSuggests that intelligence is “the ability to devise flexible solutions to problems, which includes learning, learning in new situations and thinking, reasoning and planning”

The Machiavellian Hypothesis Taken from Niccolo Machiavelli (1469-1527)

He suggested primates use a mix of cunning and deceit in order to maintain their place in a social group.

Higher level intelligenceoRichard Byrne and Andrew Whiten (1988) proposed the idea that the evolutionary origins of high-level intelligence lie in the adaptive value for social animals of ‘social manipulation, deceit and cunning cooperation

Higher level intelligenceoTheorised by Humphrey (1976) as being creative and able to infer in novel situations that something is likely to happen because it is implied by a particular combination of events.

o e.g. Man, walking reading a newspaper, hole in ground. What will the man do?

Higher levels of intelligence and social worldsoIt is useful for living in a social groupoCan use to preserve group and outmanoeuvre individual competitorsoCan help therefore to compete and co-operate.oHence why it is Machiavellian – the ablility to negotiate what is of best advantage to you at the least cost, while the individual you are interacting with is making exactly the same calculation!

Other perks of being socialoThe more social we are, the more we imitate.oWhen imitating, we are mimicking things not always happening at the same time.oThis can lead to planning and thinking about things that aren’t always happening ‘now’.oThis means we develop the ability to think abstractly and to simulate possible actions and outcomes.oThe abilities to plan, memorise and solve problems are cognitive skills that have developed and evolved.oExamples include hunting – imitate, plan, decide how to improve, memorise this, try it out!

Primitive man in the in the PTE – Pre-Tesco Era

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Evolving a Modular Mind The notion that the human mind is constituted in part by a set of usually diffused modules that serve specific cognitive-emotional functions.

A little like a swiss-army knife mind!

In hunter-gatherers this may have started with social contracts e.g. ‘I give you mammoth, you give berries’, then as money was discovered, a new module for financial transactions would be ‘added’ and so on. As further developments happened, we now have ‘modules’ for stock exchanges, futures and greedy bankers!

Example of a Social Contract Model

A social contract model may include ◦ The ability to recognise different individuals◦ A long-term memory of past exchanges with other individuals in

order to know when to co-operate and when not◦ Knowledge about what constitutes a benefit and a cost to oneself◦ Emotional reactions such as anger that signal to others that one

will pursue cheaters

oEvolutionary psychologists argue that the development of modules in our minds, which allowed us successfully to solve problems in our ancestral environment, underpins our thinking, feelings and behaviour today.

Evolutionary Understanding of Social BehaviouroThe human ability to mind-read depends on abilities to both interpret and express emotional states.oThere is evidence that much emotional expression in humans is universal.oCross-cultural psychologist Paul Ekman found people from a variety of cultures could recognise fear, disgust, happiness, sadness, anger and surprise.oEven children born blind and deaf will smile and cry with the same facial expressions as ‘non-disabled’ children

Altruism and Reciprocity Dawkins in his book The Selfish Gene suggests that evolution may be only in terms of being successful for populations not individuals.

We are related to large numbers of people genetically so promoting the welfare of all those related to us would be a useful reproductive strategy.

Mutual help would mean that although we helped others, they would help in our need.

This ‘reciprocal altruism’ explains the evolution of behaviour benefitting others who are not kin in terms of the adaptive value for our ancestors of mutual help when they needed it!

Using Evolutionary Psychology Methods include observation, hypothetico-deductive reasoning and testing, reverse-engineering (aka Functional Analysis ) this is the application of the laws of operant conditioning to establish the relationship between stimuli and responses.

and logical inference supported by evidence. Contributions to psychology include understanding of behaviour, why behaviours may occur, by asking functional questions new investigations can be designed

Criticisms include the fact it is deterministic – we have no free will, it’s all in our genes and the impact of change in the ways we live – we have different lives from the old hunter-gatherers and this may cause changes to happen quicker.

To concludeoWe’re a young species descended from monkeys!oEvolution changed us through adoption of adaptive behaviour.oThis behaviour helped humans survive and develop.oIt is suggested that we have evolved different skills and intelligence.oWe can look at evolution to figure out some of our behaviour today.oWe can look for functional explanations for why we do what we do, especially when it is not so healthy for us!

Thank you see you next week!