chapter 3: the nature-nurture debate

Question 1

what is natural selection

Answer 1

some individuals are better adapted to their environment, and offspring inherit these adapted features

Question 2

features of natural selection

Answer 2

variation, struggle, heritability, adaptions

Question 3

beaks of Darwin’s finches

Answer 3

Finches can have bigger or smaller beaks depending on what food is available
When nuts with thicker shells start to be available more often – more finches have bigger beaks because they are better adapted

Question 4

Kettlewell’s moths

Answer 4

When put on light trees – the rate of survival is higher for light moths than for dark moths – the number of dark moths drastically falls within a couple of generations
A factory opened near – ash on the nature surrounding it – dark moths have an advantage – within a few generations, the number of light moths drastically falls

Question 5

two types of animals based not heir degree of maturity when born

Answer 5

precocial (the young are physically mobile and able from the moment of birth or hatching - hens, ducks, geese, swans, sheep, horses, goats - imprinting) and altricial (the young are incapable of moving on their own and are dependent on parent for safety and food - rodents, cats, dogs, humans, many birds, marsupials)

Question 6

what is a superprecocial species

Answer 6

Maleo bird - no parental support, no need for environmental input

Question 7

sexual selection

Answer 7

some features are selected because they’re attractive to sexual partners (can be detrimental for survival)

Question 8

nativism

Answer 8

the view that many skills or abilities are native or hard wired into the brain at birth, the result of genetic inheritence

Question 9

empiricism

Answer 9

the view that humans aren’t born with built-in core knowledge or mental content and that all knowledge results from learning and experience

Question 10

who devised the first intelligence test, when and why

Answer 10

Alfred Binet, 1905, to select children unlikely to benefit from regular school systems

Question 11

mental age

Answer 11

an individual’s level of mental ability relative to others

Question 12

chronological age

Answer 12

a person’s actual age, as opposed to their mental age

Question 13

intelligence quotient

Answer 13

a measure of person’s level of intelligence compared to a population of individuals of approximately the same age, a score around 100 indicates average intelligence

Question 14

what’s the formula for IQ

Answer 14

IQ = MA/CA x 100

Question 15

four important things about IQ tests and scores

Answer 15

• The simple formula is no longer used, but the purpose of IQ tests is to compare people’s scores with those from people of the same population and age
  o The average IQ at a given time is always 100 – tests are standardised (a test of psychological characteristic that has been standardised on a representative sample of the population)
  o Children’s and adults’ raw scores tend to increase from one generation to the next
  o The items on IQ tests invariable proceed from simple to complex, an individual’s raw score is derived from the number of items passed before they make a mistake

Question 16

most well known IQ tests

Answer 16

Stanford-Binet (ages 2 to adulthood), the Wechsler scales (the Wechsler Preschool and Primary Scale of Intelligence – WPPSI, the Wechsler Intelligence Scale for Children – WISC, the Wechsler Adult Intelligence Scale – WAIS), the Differential Ability Scales (DAS-II from infancy to adolescence)

Question 17

what is G

Answer 17

the term used to denote general intelligence

Question 18

how is occupation related to IQ

Answer 18

o Teachers, doctors, accountants, pharmacists, lawyers and those in similar occupations – mean IQ over 100
o People in semi- or low-skilled occupations (barber, farmhand, labourer) have a mean IQ below 100
o Many non-cognitive factors influence test performance and job performance (reduced motivation, increased anxiety and stress, levels of self-confidence, self-esteem and self-efficacy beliefs)

Question 19

abilities of intelligence

Answer 19

o Verbal subscales
- Similarities – in what way things might be similar
- Comprehension – child’s common sense and understanding
- Recall of digits – correlates well with verbal rather than performance subscales
o Performance subscales
- Block design – the child is given a set of blocks with coloured patterns on them and asked to use them to make patterns that the tester shows
- Copying – the child is shown a drawing and asked to copy it on a sheet of paper (get progressively more complex)

Question 20

heritability

Answer 20

a statistical measure that describes how much of the variation of a trait in a population is due to genetic differences (rather than environmental differences) in that population

Question 21

types of alleles

Answer 21

dominant or recessive
o Homozygotes: AA and aa
o Heterozygotes: Aa and aA

Question 22

what does heritability mean

Answer 22

o Heritability of 0.5 means that on average, about 50% of the individual differences that we observe may be attributable to genetic differences between the individuals in that population
 Doesn’t mean that 50% of any person’s intelligence is due to their genes and the other 50% is due to their environment
 If the environment is fairly uniform, heritability may be high, if environmental differences are large, the heritability may be low

Question 23

genetic determinism

Answer 23

the hypothesis that people become who they are as a consequence of their genetic inheritance

Question 24

environmentalism

Answer 24

the hypothesis that people become who they are as a consequence of the learning and experiences they have had throughout life

Question 25

familiar resemblance

Answer 25

the resemblance between relatives whose genetic relationship to each other is known

Question 26

types of twins

Answer 26

o Monozygotic (MZ, identical) – share 100% of their genes, developed from one ovum and one sperm which divides into two shortly after conception
o Dizygotic (DZ, fraternal) – share 50% of their genes just like other siblings, conceived at the same time but result from two eggs being fertilised by different sperm

Question 27

problem with studies with identical twins raised apart

Answer 27

Even when their environment is different, it is likely that the adoption agencies will ensure that the adoptive environments are very similar

Question 28

how’s heritability of IQ at a very young age

Answer 28

23% when children are 2-4 and 62% when they’re 7-10

Question 29

McCartney explanation of heritability

Answer 29

Influence of genes is: passive (environment is not actively created by a child), evocative (evokes reactions from your environment), active – niche picking (as a child gets older, it can pick their own environment that suits their genes)

Question 30

jensen’s argument

Answer 30

African Americans have a 15 points lower IQ and because of high heritability he concluded that this is innate

Question 31

problems with Jensen’s argument

Answer 31

heritability is a measure of variance, not a biological mechanism (the high heritability of IQ doesn’t tell us something about the innateness of the trait + the heritability of IQ might be high in white middle-class environment just because of good schooling (little environmental variance) while the schooling of African Americans is probably much more variable

Question 32

what’s the missing heritability

Answer 32

the failure to find any of the genes associated with cognitive abilities
probably all genes with expression in the brain somehow relate to intelligence

Question 33

genotype

Answer 33

an individual’s inherited genetic makeup

Question 34

phenotype

Answer 34

the interaction of genetic and environmental influences to create an individual’s physical appearance and behaviour: genotype and environment interactions

Question 35

examples of phenotype things

Answer 35

PKU, COPD, breastfeeding, MAOA

Question 36

differential susceptibility

Answer 36

o Some individuals remain stable under whatever circumstances – dandelions
o Other individuals are vulnerable under negative conditions, but can excel under positive conditions – orchids

Question 37

Skeel’s study

Answer 37

orphanages - much higher IQ and better profession if left when younger than 6 months

Question 38

romanian adoption study

Answer 38

psychological and cognitive problems directly proportional to the amount of time spent in the orphanages
group of children assessed at 4,6, 11 and 15 years – spent their first few months or years in the Romanian orphanages before being adopted by good families in the UK
o Children who came to the UK before turning 6 months were able to completely catch up in terms of cognitive ability
o However those who were older than 6 months showed signs of developmental catch-up, but had cognitive levels that were well below those in the comparison group (IQ 15 points lower than the under 6-month-old group)

Question 39

environmental drift

Answer 39

changes in developmental functions that result from, and are in the direction of changing environments

Question 40

deprivation specific patterns in Romanian study

Answer 40

o Quasi-autistic symptoms – intense circumscribed interests and abnormal preoccupations – deficits in the theory of mind
o Disinhibited social engagement – disregard for social boundaries + undue familiarity with strangers and a willingness to walk off with strangers and to ask inappropriate questions
o Inattention/overactivity – shares many features with ADHD
o Cognitive impairment – reduced IQ

Question 41

SES adoption

Answer 41

65 adopted children who, prior to adoption, had been neglected or abused and had been removed from their biological families by court order
o In the year before adoption all of their IQs were below 86, average of 77
o IQs after adoption: low SES family: 85, middle SES: 92, high SES: 98

Question 42

Flynn effect

Answer 42

an increase in the average intelligence quotient test scores over generations - average IQ risen by 20 points since 1950

Question 43

raven’s progressive matrices

Answer 43

a culture-free non-verbal intelligence test with items arranged in order of difficulty

Question 44

explanations for the Flynn effect

Answer 44

a reduction in family size (children get more parental input), improvements in education, improvements in diet, and the increasing complexities of modern societies which include complex technological inventions such as computers, cell phones, video games, social media

Question 45

does Flynn effect still exist

Answer 45

Flynn effect is reducing in US and UK, rises in China and India

Question 46

malnutrition

Answer 46

a serious condition that occurs when a person’s diet doesn’t contain the right amount of nutrients

Question 47

poverty

Answer 47

the minimum level of income deemed adequate in a particular country
o Absolute poverty – limited access to food and clean water
o Relative poverty (developed countries) – households that earn 60% or less than the median income

Question 48

how many children live below the poverty line

Answer 48

In the UK and Us somewhere between 1/3 and ¼ of children live below this relative poverty line

Question 49

children from families with limited financial resources - brain differences

Answer 49

frontal lobe, temporal lobe and the hippocampus

Question 50

head start - USA, 1965

Answer 50

Aim: help break cycle of poverty of low-income children from birth to age 5 (prior to formal schooling) – provide children with comprehensive programme to support cognitive, social, nutritional and emotional needs
increase of about 10 IQ points, but disappeared after stopping - parents essential
o Positive benefits: reduced numbers of US children to repeat a grade, fewer children were placed in special education classes, teachers rated the children more positively on attitudes to teaching, the children had higher self esteem and self efficacy, in later life they were less likely to get in trouble with the police

Question 51

sure start, UK, 1998

Answer 51

o Aim: giving children the best possible start in life by providing play sessions, family support and advice, guidance on health, speech and language therapy, access to specialist support services
o Parents thought to: increase positive child behaviour through praise, improve parent-child interactions, set clear expectations, apply gentle consequences for problem behaviour

Question 52

epigenetics

Answer 52

changes in gene expression that are relatively stable during cell division, sometimes even over generations, but are independent of the genetic code itself