Title: Evolutionary Explanations of Human Behaviour
1Evolutionary Explanations of Human Behaviour
2Objectives
- Assess prior knowledge
- Define Evolution
- Define Evolutionary Psychology
3What is Evolutionary Psychology?
- Read the article on page 3 of your resource pack.
- Pick out 5 key points from the article and write
them on a post-it!
4Darwin
Natural Selection
Evolution
Genetic
Appear
Adaptive
5Mastery Test
- How much do you already know?
- Complete the multi-choice test on page 2 on paper
- Work on your own in SILENCE!!!
2min
Go!
STOP
6Marking the Test
- Swap papers!
- Mark the answers as I read them out
- How did you do?
- You will complete this again at the end of the
topic aim to improve!
7Extension Tasks
- Complete the definitions and the picture of the
model on page 1 of your workbook - Create a poster about the four parts of Modern
Darwinism
8Evolutionary Explanations of Human Behaviour
9Parental Investment
Sexual Selection
Human Reproductive Behaviour
10Objectives
- State the nature of sexual selection
- Evaluate the nature of sexual selection
- State the forms of sexual selection
- Evaluate the forms of sexual selection
- State the consequences of sexual selection
- Evaluate the consequences of sexual selection
11My ideal partner!
- Take a piece of plain paper.
- Draw the head of a person.
- Fold it over and pass left.
- Draw the body and arms of a person
- Fold it over and pass it left
- Draw the legs and feet of a person
- Fold it over and pass it left
12Key Definition!
- EEA (Environment of Evolutionary Adaptation)
- This is the environment to which a species is
adapted and the set of selection pressures that
operated at this time. - Generally regarded as the time when our ancestors
were hunter-gatherers on the African savannah.
13Nature of sexual selection Gender Specific
- Characteristics to promote reproductive success
- Men young healthy females
- Women resource investment
- Female more choosy (intersexual competition)
- Male compete with each other (intrasexual
competition)
14Evaluation
- Buss (1989) study of 37 cultures.
- Men choose on fecundity
- Women choose on resource potential
- Scheib (1994) sperm donor choice study
supported Buss findings
15Evaluation
- Bereczkei (1997) females advertised for
family-orientated men - Female financial independence
- Homosexual relationships no reproductive
potential. - Dunbar (1995a) Homosexual adverts also advertise
resources despite having no reproductive
potential
16Nature of Sexual SelectionOrigins of Mate
Preferences
- Preference for one mate over another
- Links to problem of appropriate mate choice in
EEA - Mating biased in favour of individuals with
certain characteristics - Genetic quality of mate determines genetic
quality of offspring!
17 Evaluation
- Human behaviour influenced by selective pressure
in EEA is not universally accepted. - Continuing evolution
- Why so affected by one environment and not
another?
18Forms of sexual selection Selection for
Indicators
- Indicators reveal traits that can be passed on.
- Show information about mate survival
- Tend to be condition dependent healthier
bigger or revealing make better use of
indicators, e.g. better groomed - Pre-programming
19Evaluation
- Indicators can be faked! E.g. female lips
- Handicaps only reliable indicator (Zahavi 1975)
- Facial symmetry.
20Forms of sexual selection Selection for sperm
competition
- Sperm is stored
- Size matters!
- Male humans have medium-sized testicles by
primate standards. - Ancestral males mildly competitive females must
have had multiple partners (Baker Bellis 1995)
21Evaluation
- Humans are by nature more promiscuous than
monogamous - 9 misattributed fatherhood (Baker Bellis)
- Majority of people do know who their father is
- Majority not adulterous
22Competition Activity
- Complete the human intra-sexual competition
activity. - Be prepared to share your opinions
23Consequences of sexual selectionPhysical
Characteristics
- Dimorphism (physical differences between the
sexes) is linked to female mate choice Martin et
al. (1994) - Size difference polygynous mating system (one
male, many females) - More sexual competition between males.
24Consequences of sexual selectionPhysical
Characteristics
- Facial Characteristics
- Neotenous (child-like) more attractive (Perrett
et al 1994) - Strong testosterone linked features
- Facial symmetry (Thornhill Gangstad 1993)
25Sexual selection Human mental evolution
- Physical and mental
- Neophilia (love of novelty)
- Favour the creative (Miller 1998)
26Extension Task
- Complete the task on Fishers hypothesis.
27Evolutionary Explanations of Human Behaviour
28Parental Investment
Sexual Selection
Human Reproductive Behaviour
29Objectives
- State evaluate parental investment theory
- Compare and contrast the differences between
maternal and paternal investment and evaluate
these
30Fishers Hypothesis
31Key Definition
- Parental Investment any investment by a parent
in one of his or her offspring that increases the
chance that the offspring will survive at the
expense of the parents ability to invest in any
other offspring (alive or yet to be born)
(Trivers 1972)
32Parental Investment Theory
- Trivers (1972)
- Males and females do not invest equally
- Gametes
33Evaluation
- Plausible explanation (Buss 1998)
- Men gain from polygyny. Females from monogamy.
- Polygyny common prior to Western influence.
(Smith 1984) - Reproduction rates are low among wealthy people.
- Contraception
- Socially enforced monogamy
34Maternal vs. Paternal
Egg Pregnancy Childbirth Feeding Care Symons (1979) Sperm - - - - Daly Wilson (1978)
35Evaluation
- Females want male providers because of infant
dependency - Female want good quality offspring.
- Mistaken paternity supports this.
36Cuckoldry
- Self-protection against cuckoldry
- Considerable investment need for fidelity
(Miller 1998) - Care not misdirected
37Paternal love
- Read the article on paternal love in the resource
pack - Pick out 5 key points and transfer to post-it
notes - Be prepared to share
38Sexual Jealousy
- Different adaptive problems for males and females
- Males incorrect investment
- Females diversion of resources
- Sexual jealousy a solution (Buss 1995)
- Men jealous of sexual act
- Women jealous of shift in emotional focus
39Evaluation
- Buss et al. (1992) male concerned with sexual
fidelity, female concerned with emotional
fidelity. - Galvanic skin responses
- Veil
- Changes in sexual morals
- Surplus of men means marital life is more stable
(Hill Hurtado 1996)
40Evaluation
- Dunbar (1995b) Joint parental investment is
desirable because of high cost of successful
reproduction. - Males restrict reproductive activity and invest
more in each offspring. - Greater male selectivity means female
attractiveness is important compared to non-human
animals.
41Sexual Jealousy
- Complete the activity on sexual jealousy in the
activity pack. - Be prepared to share your answers
42Extension Activity
- Complete the activity on polygyny and polyandry
- Ensure it is complete by next lesson.
43Evolutionary Explanations of Human Behaviour
44Parental Investment
Sexual Selection
Human Reproductive Behaviour
45Objectives
- State the main ideas about parent-offspring
conflict - Evaluate the main ideas about parent-offspring
conflict
46Polygyny Polyandry
47Parent-offspring conflict
- Trivers (1994)
- Parents will be in conflict about weaning,
parents will want to wean earlier than the child - Parents will encourage children to value siblings
more than they are naturally inclined to - Parents will punish conflict and reward
co-operation.
48Sibling Rivalry
- Individual offspring
- Fair share
- Maximise fitness
- Sibling rivalry for attention and resources
49Evaluation
- Lalumiere et al. (1996) Different developmental
paths - Harris (1999) Peer socialisation
50Age related parent-offspring conflict
- Begins at conception (Buss 1999)
- Pre-eclampsia
- Sibling investment
- Transfer of investment
51Evaluation
- High blood pressure beneficial (Xiong 2000)
- Alliances against non-kin
- Learned negotiation skills (Shaffer 1993) a
non-evolutionary explanation
52Parent-offspring conflict activity
- Read the article on parent-offspring conflict
- Pick out 5 key points ready to share....
53Extension Activity
- Complete the cut n stick for the first section
of the topic - Ensure it is complete by next lesson
54Evolutionary Explanations of Human Behaviour
55Parental Investment
Sexual Selection
Human Reproductive Behaviour
56Objectives
- Review what we have learned so far
- Construct an answer to an essay that
meets/exceeds ALIS target
57Mastery Test
- How much do you now know!?
- Complete the multi-choice test on page 2 on paper
- Work on your own in SILENCE!!!
2min
Go!
STOP
58Marking the Test
- Swap papers!
- Mark the answers as I read them out
- How did you do?
- Did you improve?
59AO1 AO2
- Lets look at what makes effective A01 and AO2
- Lets review some essay plans
60Writing an Essay
- Choose one of the essay titles
- Try to choose whichever you think is most
challenging to you. - Review the section of work
- Write for 30 mins
61Reviewing our Essays
- Swap with someone near to you
- Read their work
- Write one thing that is good
- Write one thing they could improve on
- Give a mark and explain why you have given this
62Objectives
- Review what we have learned so far
- Construct an answer to an essay that
meets/exceeds ALIS target
63Evolutionary Explanations of Human Behaviour
64Depression
Unipolar Disorder
Bipolar Disorder
Mental Disorders
Phobias
OCD
Anxiety
65Objectives
- State the symptoms of depression
- State the differences between unipolar and
bipolar disorder - State the evolutionary explanations of unipolar
disorder - Evaluate the evolutionary explanations of
unipolar disorder
66Mastery Test
- How much do you already know?
- Complete the multi-choice test on page 2 on paper
- Work on your own in SILENCE!!!
2min
Go!
STOP
67Marking the Test
- Swap papers!
- Mark the answers as I read them out
- How did you do?
- You will complete this again at the end of the
topic aim to improve!
68Depression is
- Using mini-whiteboards in groups of 3
- Create a mind map of symptoms of depression.
- You have 5 minutes!
- Be ready to share your answers!
69Unipolar and Bipolar Disorder
- Unipolar
- Consists of depressive phase only
- Bipolar
- Consists of manic and depressive phases and shift
between the two
70Evolutionary Explanations of Depression
Unipolar Disorder
Bipolar Disorder
Social Competition Hypothesis
Defection Hypothesis
Reproductive Fitness
EOBD Hypothesis
71Social Competition Hypothesis
- Price et al (1994)
- Depression is an evolved response to loss of
status - An adaptive response to losing rank and seeing
self as a loser - Prevents risk of further injury
- Preserves relative stability of social group
- Prevents further competition
72Evaluation of social competition hypothesis
- Difficult to test
- Gilbert Allan (1998) found feelings of defeat
were significantly correlated with depression - Rank Theory (Price Sioman 1987)
- Yielding subroutine
- Winning subroutine
73Evolutionary Explanations of Depression
Unipolar Disorder
Bipolar Disorder
Social Competition Hypothesis
Defection Hypothesis
Reproductive Fitness
EOBD Hypothesis
74The defection hypothesis
- Hagen (1999)
- Post-natal depression an adaptive response led
women to limit investment in the child as this
would reduce overall reproductive success. - Hagen (2002)
- Can be generalised to all forms of depression
because it is a response to an event that has an
evolutionary significant cost
75Evaluation of defection hypothesis
- Considerable empirical support
- Lack of social support predicts this (Gotlib et
al. 1991) - Poor environment predicts this (Warner et al.
1996) - Post-natal depression results in loss of interest
in child (Beck 1992) - Post-natal depression leads to increased paternal
investment (Hagen 2002)
76Extension Task
- Complete the case study 1 activity on your
whiteboard.
77Case Study 1
78Homework
- Log onto www.ashlawnpsych.wordpress.com
- Follow the instructions under the post Year 13
Evolutionary Homework due 9th October
79Objectives
- State the symptoms of depression
- State the differences between unipolar and
bipolar disorder - State the evolutionary explanations of unipolar
disorder - Evaluate the evolutionary explanations of
unipolar disorder
80Evolutionary Explanations of Depression
Unipolar Disorder
Bipolar Disorder
Social Competition Hypothesis
Defection Hypothesis
Reproductive Fitness
EOBD Hypothesis
81Objectives
- State the symptoms of depression
- State the differences between unipolar and
bipolar disorder - State the evolutionary explanations of bipolar
disorder - Evaluate the evolutionary explanations of bipolar
disorder
82Homework
- Log onto www.ashlawnpsych.wordpress.com
- Follow the instructions under the post Year 13
Evolutionary Homework due 9th October
83Reproductive fitness
- Beneficial genes are passed on
- Possession of bipolar genes an advantage
- Small doses v large doses normal distribution
curve
84Evaluation
- Based on assumptions caused by multiple genes
and the genes are linked to desirable behaviour - Lack of genetic evidence chromosome 22 (Kelsoe
et al. 2001) - Twin studies high concordance (Nesse 1999)
- Number of genes involved
- Expression of gene may be modified
85Evolutionary Explanations of Depression
Unipolar Disorder
Bipolar Disorder
Social Competition Hypothesis
Defection Hypothesis
Reproductive Fitness
EOBD Hypothesis
86EOBD Hypothesis
- Sherman (2001) bipolar behaviours are
adaptations to the selective pressures of long
severe winters and short summers.
87Evidence for EOBD
- Cold-adapted physique
- Bipolar linked to thick compact physique
- Large trunk, small extremities
- Improved clothing and shelter made this
adaptation unnecessary - (Kretschmer 1970)
88Evidence for EOBD
- Hibernation
- Bipolar evolved in response to environmental
adversity - Depressive phase resembles hibernating behaviour
- For example overeating then lethargy and
depression similar to animals gorging and then
sleeping. (Sherman 2001)
89Evidence for EOBD
- Adaptive significance in social groups
- Inactivity in winter preserves harmony and
survival - High energy requirement
- Mania link to challenge, survival and emergencies
- Aiello Wheeler
- (1995)
90Evaluation of EOBD
- Previc (2002) Hypothesis is unproven
- Makes intuitive sense
- Tries to explain original development not cause
- Arbisi et al. (1994)
- Neurophysical support dopamine fluctuates
seasonally
91Case study 2
- Read case study 2
- Complete the questions on paper
- Be ready to share your answers!
92Extension Task
- Complete the comparison flow chart between
unipolar and bipolar disorder
93Flowcharts
94Objectives
- State the symptoms of depression
- State the differences between unipolar and
bipolar disorder - State the evolutionary explanations of bipolar
disorder - Evaluate the evolutionary explanations of bipolar
disorder
95Depression
Unipolar Disorder
Bipolar Disorder
Mental Disorders
Phobias
OCD
Anxiety
96Objectives
- State the symptoms of anxiety
- State some types of anxiety disorders
97(No Transcript)
98Anxiety is
- Using big paper and pens in groups of 3
- Create a mind map of symptoms of anxiety.
- You have 5 minutes!
- Be ready to share your answers!
99Anxiety
- Anxiety can be defined as feelings of
apprehensiveness or dread in response to threats
that are real or imagined
100Symptoms of anxiety
101The nature of anxiety
- General vs. Specific (Janzen 1981)
- General threat general response
- Specific threat Specific response
102Anxiety as protection
- Four responses (Marks 1987)
- Escape or avoidance
- Aggressive defence
- Freezing/immobility
- Submission or Appeasement
103Types of anxiety disorder
- Phobias
- OCD
- PTSD
- You could be asked to explain two of these from
an evolutionary perspective
104Subtypes
- Subtypes of anxiety have evolved to defend
against threat. - Fear linked to survival but excessive fear can
cause problems such as phobias and OCD
105Threat situations and fear response (Mark Nesse
1994)
- Heights Induce freezing so unlikely to fall,
excess fear of small heights e.g. stairs - Public places guards against danger away from
home territory, excess agoraphobia - Post-traumatic fear Avoidance of repeated
trauma, excess PTSD - Social threats minimize threat of group
rejection, excess dysmorphophobia OCD
106Obsessive-Compulsive Behaviour
- Exaggeration of mechanisms that drive adaptive
behaviour - Grooming behaviour reduces parasitism in
mammals -gt excess washing - Concern for others ensures group stability -gt
fear of harming others - Hoarding guards against shortages -gt hoarding
of all things
107Is anxiety adaptive?
- Without it you would die! (Tyrell Baxter 1981)
- Adrenal gland removal death
- Pleasurable fear films, roller-coasters
- Learning
- Why might anxiety be maladaptive?
108Are anxiety disorders inherited?
- Kendler et al. (2000) 3000 twin studies common
genetic factor in all phobias and unique genetic
factor for specific ones. - Nestadt et al. (2000) People with a first-degree
relative with OCD 5x more likely to have OCD in
their lives than those without.
109Anxiety
Adaptive
Maladaptive
110Extension Task 1
- Read the anxiety article in the resource pack
- Pick out five key points
111Extension Task 2
- Find an example of a story about fear in the
media and bring to next lesson
- Make a list of treatments for anxiety disorders
and the main components (at least 3)
112Objectives
- State the symptoms of anxiety
- State some types of anxiety disorders
113Depression
Unipolar Disorder
Bipolar Disorder
Mental Disorders
Phobias
OCD
Anxiety
114Objectives
- State types of anxiety disorder
- State and evaluate Pre-potency
- State and evaluate Preparedness
115Phobias Extension Task
- What were your key points?
116Evolution of Anxiety Disorders
- Ancient fears
- Snakes, heights, storms, darkness, strangers,
seperation - Phobias exaggeration of these fears
- Other stimuli eg, leaves no threat no phobia
- Modern dangers eg cars rarely form phobias
because these have not been around long enough to
have influenced adaptive selection.
117Pre-potency
- Evolved to respond to potential threat (little
point in experiencing anxiety after a loss!) - Ancestors able to respond to threats more likely
to survive and more likely to pass on genes. - Natural selection shaped nervous system to
respond to cues - E.g. noise and visual stimuli of a snake-like
object may cause big anxiety response - This is PRE-POTENCY where something has power
to direct experience.
118Evaluation ofPre-potency
- Ohman Soars (1994)
- Masked pictures bigger anxiety response than
neutral pictures
119Evaluation ofPre-potency
- Bennet-Levy Marteau (1984)
- Form and texture different to human greatest
fear. - 1 exception slugs!
120Preparedness
- Learning rather than fixed response
- Seligman (1970) learn an association between
stimuli and fear, once learned, difficult to
extinguish, passed on genetically. - Fear in infants gauged by mothers reaction.
(Marks 1987)
121Evaluation
- Strangeness is the problem not the stimulus
itself. - Prepared to fear the strange learn not to.
- Explains high rate of phobias in childhood and
adolescence and reduction in adulthood.
122Evaluation
- We learn some fears readily and these are
difficult to unlearn. McNally (1987) - Expectancy bias fear relevant stimulus (danger,
unpleasantness) produces future responses. No
need to invoke evolutionary history. - Modern phobias unexplained (eg. Hypodermic
needles)
123Nausea and Alcohol
- Garcia Koelling (1966) rats saccharin
- Berstein (1978) Ice-cream Chemotherapy
- Why do people persist in drinking alcohol when it
makes them feel sick?
124Little Albert
- Complete the activity on Little Albert from your
resource pack - Be ready to share your answers!
125Extension Task 1
- Complete the Evolutionary explanations of mental
disorders task.
126Extension Task 2
- Mind map an essay title for depression and for
anxiety - Choose the one you are then least comfortable
with and write it!
127Objectives
- State types of anxiety disorder
- State and evaluate Pre-potency
- State and evaluate Preparedness
128Evolutionary Explanations of Human Behaviour
129Depression
Unipolar Disorder
Bipolar Disorder
Mental Disorders
Phobias
OCD
Anxiety
130Objectives
- Review what we have learned so far
- Construct an answer to an essay that
meets/exceeds ALIS target
131Mastery Test
- How much do you now know!?
- Complete the multi-choice test on page 2 on paper
- Work on your own in SILENCE!!!
2min
Go!
STOP
132Marking the Test
- Swap papers!
- Mark the answers as I read them out
- How did you do?
- Did you improve?
133AO1 AO2
- Lets look at what makes effective A01 and AO2
- Lets review some essay plans
134Writing an Essay
- Choose one of the essay titles
- Try to choose whichever you think is most
challenging to you. - Review the section of work
- Write for 30 mins
135Reviewing our Essays
- Swap with someone near to you
- Read their work
- Write one thing that is good
- Write one thing they could improve on
- Give a mark and explain why you have given this
136Objectives
- Review what we have learned so far
- Construct an answer to an essay that
meets/exceeds ALIS target
137Evolutionary Explanations of Human Behaviour
138Foraging
Language
Development of Human Intelligence
Social Theories
Brain Size
139Objectives
- State and evaluate evolutionary factors in the
development of human intelligence including - Foraging demands
- Social demands
- Language
140Mastery Test
- How much do you already know?
- Complete the multi-choice test on page 2 on paper
- Work on your own in SILENCE!!!
2min
Go!
STOP
141Marking the Test
- Swap papers!
- Mark the answers as I read them out
- How did you do?
- You will complete this again at the end of the
topic aim to improve!
142Intelligence is
- Using big paper and pens mind map in pairs what
you think intelligence is - Include anything you think is associated with
intelligence - Be ready to share!
143Some key definitions
- Intelligence the ability to think flexibly
- Primates includes lemurs, monkeys and apes
- Great apes the most advanced group of primates
including gorillas, chimpanzees and humans - Hominids early humans
144Why did intelligence evolve?
- Survival
- Food
- Shelter
- Mating
145Foraging Finding food
- Dunbar (1992)
- Fruit-eaters had high cognitive demand
- Needed to monitor food supply and ripening
patterns, develop harvesting plans and survive in
the interim - Leaf-eaters had lower cognitive demand as food
more readily available - Hominids were fruit eaters
146Foraging tool use
- Mercader et al. (2002)
- Chimps use stones as hammers to crack open nuts
- Most successful hunter-gatherers also used tools
- These tribes survived
147Evaluation of foraging
- Is tool use a cause or an effect of intelligence?
- Is tool use developed by trial and error
learning? - Visalberghi Trinca (1987) Monkeys used trial
and error to find suitable tools and showed no
understanding of why one worked and not another - Byrne (1995) only chimps use tools in the wild
148Social Theories
- Machiavellian Intelligence (Whiten Byrne (1998)
Human intelligence may be an adaptation to
social problem solving. Individuals able to use
others without causing aggression would be
favoured. This deceit seems cooperative but is
actually selfish
149Evaluation
- Dunbar (1992)
- Strong positive correlation between group size
and neocortex ratio - Polygamous primates had a larger neocortex ratio
than monogamous ones polygamy involves more
complex social relations
150Machiavellian Intelligence
- Forming alliances
- Harcourt (1992)
- Power in social groups right allies not
physical strength - Alliances formed based on ability to provide
useful future help
151Machiavellian Intelligence
- Manipulation deception
- Byrne (1995)
- Manipulate others into providing unwitting help
- Ability to understand and plan deception
- Diversions of attention
152Evaluation
- Byrne Whiten (1992)
- Strong positive correlation between amount of
tactical deception and neocortex ratio - Suggests a clear relationship between social
manipulation and intelligence
153Evaluation
- Cosmides (1989)
- Variations of the Wason card task
- Particpants solved it 75 of the time if it is a
social context - Only solved 21 of the time with unfamiliar
context - Suggests a link between intelligence and social
problems
154D
F
7
3
If a card has a D on one side it has a 3 on
the other side. Which cards do you need to turn
over to find out if this is true?
155Beer
Coke
25
16
You are a bouncer in a bar. You must make sure
that no under-age drinkers have beer. Each card
is a customer It says age on one side and drink
on the other Which cards need turning over?
156Meat-sharing Hypothesis
- For ancestors in the EEA meat was an important
source of saturated fat - Chimpanzees face similar problems today
- When they do manage to kill they eat the fattiest
parts first not the lean tender flesh
157Meat - sharing
- Meat could be used to form alliances
- Meat could be used to persuade females to mate
- Stanford (1992) observed
- Males withheld meat until after sex
- Hunting more prevalent when females were sexually
receptive - Sexually receptive females had more success when
begging for meat - Requires individual recognition and scores of
debts, credits and relationships
158Evaluation
- Hill Kaplan (1988)
- Men in Paraguay give women meat for sex
- Gilby (2001) males share meat with receptive and
non-receptive females - Mitani and Watts (2001) males share meat with
other males to form alliances because hunting was
more successful in groups
159Language
- Humans are the only species to develop this
spontaneously. - Other species show precursors attributing
intentions and beliefs to others (eg. Sally-Anne
test) - Chimpanzees and gorillas express thoughts and
emotions through sign language and understand
human communication
160Evaluation
- Human language is likely to be the outcome of
rather than the cause of intelligence - Once language evolved it had a significant effect
on further intelligence development - Cultural transmission is only possible through
language - Vygotsky language transforms elementary mental
functions (possessed by all animals) into higher
mental functions
161Human Intelligence
- Read the article on human intelligence in the
resource pack - Pick out 5 key points and write them on post-it
notes. - Be ready to share!
162True or False?
- Complete the activity True/False questions of
intelligence using what we learned today. - How will you do?
163Extension Activity
- Using Activity 8 on Cosmides and Toobys study,
conduct the experiment and bring your results to
next lesson
164Objectives
- State and evaluate evolutionary factors in the
development of human intelligence including - Foraging demands
- Social demands
- Language
165Evolutionary Explanations of Human Behaviour
166Foraging
Language
Development of Human Intelligence
Social Theories
Brain Size
167Objectives
- State and evaluate theories into the relationship
between brain size and intelligence including - Comparative studies
- Human Studies
168Cosmides Tooby
- What were the results of your study?
169Brain Facts
- 2 of body mass 20 of metabolic rate
- Large brains would not have evolved unless they
gave humans a significant advantage - Important in cognitive development
170Comparative studies
171Brain Quantity
- Absolute brain size Most intelligent species
would be the ones with the biggest brains sperm
whale - Big brain big body
- Need to control and maintain big body needs a big
brain
172Brain quantity
- Brainbody ratio
- Jerison (1978)
- Encephalization quotient (EQ)
- Actual brain mass is divided by expected species
brain size - High EQ High intelligence
- Humans 7 (highest), other primates 2.34,
Dolphins 4.5
173Evaluation
- EQ not supported by research
- Macphail (1982) rats and squirrels had the same
performance on a learning task but rat EQ 0.40
squirrels EQ 1.10 - Different species comparison is difficult.
- Different perceptual systems
174Brain Quality
- Holloway (1979)
- Growth of the neocortex is responsible for
evolution of intelligence - Mammals 6 layers of neocortex
- Cetaceans (whales, dolphins) 5 layers.
175Evaluation
- Cetacaens are highly intelligent
- Herman (1986) Dolphins can understand human
language and perform complex tasks beyond the
ability of chimpanzees. - Fewer neocortical layers but the same neural
density and size of frontal lobes as humans
176Brain size in Humans
177Head size and IQ
- Sir Francis Galton (1888)
- Studied Cambridge undergraduates
- Insignificant relationship between head size and
intelligence - Wickett et al. (1994) repeated and found
significant relationship - Broman et al. (1987) Head perimeter at birth
predicted head perimeter at age 7 and head
perimeter at both ages predicted IQ
178MRI measures
- A recent development which allows accurate
measurement of brain size - Andreasen et al. (1993) found significant
relationship - Tan et al. (1999) used male and female Turkish
students and found a significant relationship.
179Evaluation
- Other meaningless correlations also found, eg.
Amount of cerebrospinal fluid and IQ (Egan et al.
1994) - Other causal factors of big brains!
- Diet
- Some aspects of intelligence not measure by IQ
tests so may be normal in terms of IQ. E.g.
expertise is critical to survival and requires
brain capacity but not measured by IQ tests - No simple relationship between brain size and IQ
180Brain Structure in humans
181Cortical Neurones
- Haug et al. (1987)
- Correlation between brain size and number of
cortical neurones
182Evaluation
- Relationship between neurones and brain size is
supported by animals reared in enriched
environments have more neurones - Diamond (1991) rats reared in enriched
environments had larger brains and more neural
connections. - Brain development relies on experience
183Grey matter
- Size of the regions of the brain associated with
intelligence is under tight genetic control - Thompson et al. (2001) MRI twin study
- Volume of grey matter is highly heritable and an
important determinant of IQ
184Evaluation
- Development of grey matter is affected by genes
and environment - Young adults have more grey matter than
middle-aged people likely to be due to improved
diet (Storfer 2001)
185Sex differences
- Ankey (1992)
- Brains of men larger than brains of women in both
European-American and African-American cultures - Supported by similar studies by Rushton (1992)
Pakkenberg Gundersen (1997)
186Evaluation
- Size differences are accurate
- Research cannot account for men and women
obtaining the same IQ scores (Peters 1993) - Ankey (1992) different intellectual abilities
- Female brains may be better organised (Johnson
1996) as women have larger corpus callosum.
187The intelligence gene
- Read the article in the resource pack
- Pick out 5 key points and write them on post-it
notes - Be ready to share
188Thats all folks!
- That is all the input on Evolutionary Psychology
- Complete the quiz at the end of your resource
pack using your knowledge of the whole topic!
189Objectives
- State and evaluate theories into the relationship
between brain size and intelligence including - Comparative studies
- Human Studies
190Evolutionary Explanations of Human Behaviour
191Foraging
Language
Development of Human Intelligence
Social Theories
Brain Size
192Objectives
- Review what we have learned so far
- Construct an answer to an essay that
meets/exceeds ALIS target
193Mastery Test
- How much do you now know!?
- Complete the multi-choice test on page 2 on paper
- Work on your own in SILENCE!!!
2min
Go!
STOP
194Marking the Test
- Swap papers!
- Mark the answers as I read them out
- How did you do?
- Did you improve?
195AO1 AO2
- Lets look at what makes effective A01 and AO2
- Lets review some essay plans
196Writing an Essay
- Choose one of the essay titles
- Try to choose whichever you think is most
challenging to you. - Review the section of work
- Write for 30 mins
197Reviewing our Essays
- Swap with someone near to you
- Read their work
- Write one thing that is good
- Write one thing they could improve on
- Give a mark and explain why you have given this
198Objectives
- Review what we have learned so far
- Construct an answer to an essay that
meets/exceeds ALIS target