Week 11 - Human Development

Question 1

What is developmental psychology?

Answer 1

The study of how behaviour changes over the life span.

Change can occur due to physical maturation, be shaped by experience or a combination of both.

Thus, both nature - our genetic makeup- and nurture - the shaping environment and our experiences - play powerful roles in shaping development.

Question 2

Example of complexity in nature vs. nurture debate (Hart and Ridely)

Answer 2

Hart and Ridley (1995) published a study that showed that parents who speak to their children a lot produce children with larger vocabularies than parents who do not speak to their offspring as much.

This provides evidence for the powerful effects environmental influence on children’s vocabulary right?

Or could it be that parents who speak a lot to their children are genetically predisposed to have higher vocabularies themselves and they pass on this advantage to their children?

Question 3

Nature and nurture - disentangling the two

Answer 3

Nature and nurture are hard to disentangle - it’s easy to mistake an environmental effect for a genetic effect and vice versa. Here are some of the ways that genes and environment can intersect, making it difficult to separate out the influence in each.

Question 4

What is the gene- environment interaction?

Answer 4

The effects of genes may depend on the environment and how the individual responds to this environment.

Example: people who possess a gene that results in low production of an enzyme called monoamine oxidase (MAO) May be at increased risk of becoming violent criminals.

Whether this genetic risk factor is associated with violent behaviour depends on whether children were exposed to a history of maltreatment (such as physical abuse).

Question 5

Is there a warrior gene?

Answer 5

MAOA is an enzyme that metabolises monoamines, such as serotonin norepinephrine and dopamine.

MAOA low -> biased development of neural systems and circuits -> hyperactive amygdala and underactive vmPFC -> increased negative emotional/impulse control -> increased likelihood and intensity of aggressive response to provocation

Question 6

Example of nature vs. nurture with Niche Picking hypothesis.

Answer 6

Tendency of individuals with certain genetic predispositions to seek out and create environments that permit the expression of those predispositions.

Nice picking hypothesis of Scarr and McCartney (1983)

• genes affect an individuals preference for particular environments
• the environment then affects development of the individual
• generically similar people will tend to select similar environments, thus leading to similar IQ
• it is possible that genetic predisposition influences individuals to tend towards environments that accentuate that disposition, thus leading to increased heritability throughout their lifespan

The niche picking hypothesis supports the influence of genetics on IQ

Another example is that extroverts May deliberately engage with others like themselves

Question 7

Gene expression in nature vs. nurture

Answer 7

Environmental influences actually turn genes on and off throughout our lives.

Gene C controls the colour of the fur in Himalayan rabbits. The gene is only active at temperatures in the range 15-25 celcius.

The rabbit reared at 20 degrees shows pigmentation in areas where the rabbit loses most heat. the rabbit at 30 degrees does not

Question 8

Implications of predisposition with genes

Answer 8

Children with genes that predispose them to anxiety may never become anxious unless a highly situation (eg early death of a parent in early development) could trigger these genes to become active.

Question 9

What is Lamarcks hypothesis?

Answer 9

Behavioural epigenetics provides a mechanism through which acquired behavioural and psychological characteristics might be inheritable, resurrecting the Lamarck hypothesis.

Lamarckism (or Lamarckian inheritance) is the hypothesis that an organism can pass on characteristics that it has acquired during its lifetime to its offspring. It is also known as the inheritance of squired characteristics.

Question 10

Studying developmental finding - how do we track changes with cross sectional design.

Answer 10

Cross- sectional design:
A design in which researchers examine people who are of different ages at a single point in time - Snapshot approach.

Group 1, 2 and 3 are compared at the same time. Convenient: data can be gathered quickly.

Question 11

Problem with cross- sectional design of developmental design: cohort effects

Answer 11

Effects due to the fact that groups that lived during one time period called cohorts, can differ from other cohorts.

Example of potential cohort confound:

• studying cognitive performance in young and ild adults using a computer task
• people of certain age range may have similar characteristics influenced by a variety of factors (e.g. exposure to a natural disaster, war, educational system, etc.)

Question 12

What is the only way to guard against cohort effects when investigating the way people change over time?

Answer 12

A longitudinal design study.
Psychologists tract the development of the same group of people over time.

Advatanges:

• help provide causal information as each person serves as his or her own control
• help assess role of individual differences factors

Disadvantages:

• time consuming
• expensive
• problems with participant attrition

Question 13

What are two things is developmental research to be aware of?

Answer 13

1. Assuming that an observed correlation is due to causation (after this, therefore because of this).
2. Development and experience have bidirectional influence in each other, e.g. parents influence their children’s behaviour, which in turn influences parents reactions

Question 14

Physical development: prenatal and infant physical development

Answer 14

• the prenatal period of development begins with conception and ends at birth (ca. Nine months later)
• the fertilised egg, called a zygote, is made up of genetic material (46 chromosomes grouped into 23 pairs).
• a developing baby is called an embryo through the eighth week of gestation (pregnancy)
• after the eighth week of pregnancy and until birth occurs, a developing baby is called a fetus

Question 15

What’re some obstacles to normal fetal development

Answer 15

Although most babies are born healthy and fully intact, feral development can be disrupted in four ways:

1. Premature birth
2. Low birth weight (defined as less than 2.5 kilograms for a full term baby)
3. Exposure to hazardous environmental influences and
4. Biological influences resulting from genetic disorders or errors in cell duplication during cell division

Question 16

What’re teratogens?

Answer 16

Environmental factors that can affect prenatal development negatively. They range from drugs and alcohol to chicken pox and x-rays.

Feral alcohol spectrum disorder refers to a collection of disorders called by prenatal exposure to alcohol

Question 17

Toddler and preadolescent physical development

Answer 17

Survival instincts: infant reflexes:
Infants are born with a large set of automatic motor behaviours - or reflexes-. Reflexes fulfil important survival needs. One is a sucking reflex, an automatic response to oral stimulation.

Movement milestones:
Includes sitting up, crawling, standing unsupported and walking.

Fine and gross motor skills develop in a predictable order

Motor skills emerge in sequence from the head to the feet and from the centre of the body to outward.

Question 18

Sex differences in toddler and preadolescent physical development

Answer 18

• girls typically develop fine motor skills, such as drawing or stringing beads more quickly than boys
• boys typically develop gross motor skills, such as climbing or jumping, more quickly than girls
• this May also be influenced by the type of activity girls and boys practise more.

Around the age of 8-9, the brain grows to nearly the same size as an adult as different parts such as the frontal lobes develop. Hence, children’s cognitive capacity increases.

Question 19

Adult physical development

Answer 19

• adults reach their peak levels of strength, agility, stamina, and vigour during their twenties.
• by the age of 30, each of these begins to decline. Older adults typically show declines in balance, coordination, and reaction time.
• fertility in males and females declines rapidly after age 35. Women may remain fertile until about age 50 when their Estrogen levels drop steeply and they undergo menopause, or the cessation of menstrual periods
• although men remain fertile for longer than women, sperm quality decreases.

Question 20

Outline Piaget’s theory.

Answer 20

Piaget’s theory: how children construct their worlds - Swiss physcologjst Jean Piaget (1896-1980) was the first to present a comprehensive account of cognitive development.

Piaget observed that children do not think like adults, they are not miniature adults - children’s thinking is qualitatively different.

Piaget is a stage theorist - thinking reorganises at specific transition points.

Sensorimotor-birth to 2 years-no thought beyond immediate physical experiences

Preoperational-2-7years- able to think beyond the here and now, but egocentric and unable to perform mental transformations

Concrete operational-7-11 Years- able to perform mental transformations but only on concrete physical objects

Formal operational-11 years to adult- able to perform hypothetical and abstract reasoning

Question 21

Sensorimotor stage of Piaget’s theory

Answer 21

Children’s main sources of knowledge, thinking and experience are their physical interactions with the world

-children integrate new information learned from experience into their existing understanding of the world in a process called assimilation. Eg. A child seeing a zebra for the first time and calling it a horse.

-they modify or create new schemes as a result of experience in a process called accomodation.
Eg. The first time the child sees a cow, he calls it a horse (it fits in with his current scheme). He then learns that this is a different animal entirely and develops a new schema

Infants in this state have no concept of object permanence. Understanding that objects continue to exist even when out of view

Question 22

Preoperational stage of Piagets theory

Answer 22

Proposed that from 2 until about 7 years, children pass through a stage marked by an ability to construct mental representations of experience.

• children in this stage can use such symbols as language, drawing and objects as representations of ideas
• have object permanence
• are egocentric: cannot see the world through anyone’s eyes but their own
• children construct mental representations, but they cannot perform mental transformations - Piaget developed a series of conservation tasks to test this

Question 23

What is Piaget’s conservation task?

Answer 23

Piaget filled two cups of water which were level, then poured one into a more narrow glass. Participants at the preoperational stage then suggested that the more narrow glass had more water

Question 24

Concrete operational stage in Piaget’s theory of learning?

Answer 24

Between 7 and 11 years old, according to Piaget, children enter a stage characterised by the ability to perform mental operations, but only for actual physical events.

• can understand which actions can or cannot affect concrete objects
• can also perform organisational tasks (eg sorting coins, organise a battle field) but need for physical experience as an anchor for their mental representations

Formal operations stage: emerges in adolescence. Children Aquire the capacity to reason about abstract concepts. This is the most sophisticated type of thinking: hypothetical reasoning

Question 25

What is Vygotskys theory?

Answer 25

At around the same time that Piaget was developing his theory, Russian researcher Lev Vygotsky (1896-1934) was developing a different theory of cognitive development.

• Vygotsky was particularly interested in how social and cultural factors influence learning - he observed parent and other caretakers tend to structure the learning environment for children
• developed the notion of some of proximal development as the phase when children are receptive to learning a new skill but are not her successful at it -for any given skill children move from a phase when they cannot learn it, even with assistance, to the zone of proximal development, during which they are ready to make use of scaffolding

Question 26

Differences between Piaget’s and Vygotsky’s theories?

Answer 26

Vygotsky believed that social context and social constructivist played a huge role on learning. Piaget did not.

Piaget emphasised general stages of learning and Vygotsky did not.

Piaget believed language played a minimal role whereas Vygotsky believed language played a major role.

Piaget thought children should be given support to explore their world and discover knowledge, Vygotsky believed in establishing children to learn from skilled peers or a teacher.

Question 27

Modern perspectives on cognitive development

Answer 27

Theories like those proposed by Lev Vygotsky and Jean Piaget assume that infants are born as blank slates and that all knowledge is acquired through learning.
In the 1980s, this view became challenged

Violation of expectation experiments: contradict object permanence assumptions. It has been demonstrated in infants as young as three and a half months of age.

Question 28

Tests of egocentricity and how it contradicts Piaget:

Answer 28

According to Piaget, preoperational children fail to understand that other people may possess different preferences than they do due to an egocentric way of thinking.

Recent data shows that toddlers choose foods they know the other person prefers, even if they do not like that food themselves.

Question 29

Theory of mind experiments and how it contradicts Piaget

Answer 29

The ability to attribute mental states (such as knowledge) to others and to reflect on one’s own mental states.

Early work indicated that this ability to view the world through someone else’s perspective is post preoperational (after 7 years of age).

Question 30

Theory of mind experiment (Sally’s marble)

Answer 30

Sally puts her marble in a basket, leaves the room and the child watched as Anne transfers the marble to the box. Sally returns and the child is asked where Sally will look for her marble. If the child has developed a theory of mind, they will say that Sally will look in the basket, EVEN THOUGH they know where their marble is.

Children can succeed at this task at around age 4 or 5, earlier than in Piaget’s model.

There is evidence suggesting theory of mind in animals.

Question 31

Social and moral development: key notions

Answer 31

Temperament
-at birth, babies differ in temperament - their characteristic patterns of emotional reactivity - and these differences tend to remain stable across their lifespan.

• babies with a highly reactive limbic system are more likely to have strong reactions to potentially stressful situations. This emotional style is largely contributed to our genes.

Stranger anxiety: refers to the tendency for infants to feel uncomfortable or frightened when approached by someone they do not know.

Separation anxiety involves a developmentally normal fear of being away from a trusted caregiver.

Question 32

Attachment between newborns and their primary caregivers

Answer 32

The quality is the infant- caregiver bond strongly influences an individuals social relationships throughout the lifespan.

Question 33

Imprinting as a basic form of attachment

Answer 33

• Goslings and ducklings highlight the process of imprinting, whereby early sensory experience modifies behaviour permanently
• Filial imprinting in human: during the first week of life (but not later). Also, infant rats develop a lifelong preference to odours associated with their mothers nipples.

These environmental factors are especially influential in early life, during temporal windows called critical periods.

Question 34

Harry Harlow: monkey love experiments 1950s

Answer 34

• although the baby monkeys routinely went to wire mothers for milk, they spend much more of their time with terry cloth mothers.
• when Harlow exposed monkeys to a scary stimulus, they were much more likely to run to the terry cloth mother
• Harlow termed this phenomenon contact comfort: the positive emotions afforded by touch

Question 35

Impact of parenting on development

Answer 35

Parenting styles can be divided into four types based on two dimensions of warmth and control

Authoritative parenting, which balances warmth with clear limits, promotes healthy development

Other including permissive, uninvolved and authoritarian produce misbehaving or unhappy children.

Question 36

Stages of social and emotional development

Answer 36

Erik Erickson (1902-1994) developed the most comprehensive theory of how identity develops.

Erikson suggested that individuals proceed through several stages of development throughout the lifespan. Each stage corresponds to a developmental period and involves a conflict to be resolved.

As we negotiate each stage, each “identity crisis” we acquire a more fleshed out sense of who we are.

Question 37

Where are some of the places where nature and nurture intersect?

Answer 37

Gene-environment: the impact of genes on behaviour depends on the environment in which the behaviour develops

Nature via nurture: genetic predisposition can drive us to select and create particular environments, leading to the mistaken appearance of a pure effect of nature

Gene expression: some genes ‘turn on’ only in response to specific environmental events

Epigenetics: whether genes are active is regulated by day to day and moment to moment environmental conditions.

Question 38

Epigenetics

Answer 38

The study of heritable changes in gene expression (active versus inactive genes) that do not involve changes to the underlying DNA sequence - a change in phenotype without a change in genotype - which in turn affects how cells read the genes

It refers to external modifications to DNA that then genes “on” or “off”.

Question 39

Examples of epigenetics

Answer 39

DNA methylation: the addiction of a methyl group, or a “chemical cap” to part of the DNA molecule, which prevents certain genes from being expressed.

Histone modification: histones are proteins that DNA wraps around. If histones squeeze DNA tightly, the DNA cannot be “read” by the call. Modifications that relax the histones can make the DNA accessible to proteins that “read” genes.

Question 40

Epigenetics provides a framework for

Answer 40

Understanding how the expression of genes is influenced by experiences and the environment to produce individual differences in behaviour, personality, cognition and mental health.

Question 41

What is an example of the Lamark hypothesis in relation to giraffes?

Answer 41

Giraffes neck gross longer during its lifetime, as it stretched to reach leaves, passing this adaptation to its offspring.

Darwin: natural selection allows the survival of giraffes with longer necks