Module 1 - Ch 2

Module 1 - Ch 2

1. What is a developmental theory?

   • A set of statements that are an orderly and integrated description, explanation, and prediction of human behaviour in various developmental domains. 
   • What are good qualities of a theory?
     • Internally consistent
       • its different parts fit together in a logical way
     • Provide meaningful explanations
     • Open to scientific evaluation

2. How do developmental theories differ?

   • See notes
     • 1: to what degree is a given developmental change due to maturation (nature) or experience (nurture) 2. Is the development continuous or a series of discontinuous stages?  3. Does the individual take an active or passive role in their development?  4. Does the theory itself seek to explain a broadly defined or more narrowly focused aspect of development.  5. Does one path of development characterise all individuals or are there several possible paths and directions? 
   • Maturation or Experience? Nature vs Nurture
     • Maturation = developmental thru biology
   • Continuous or Discontinuous? (many changes vs single stages)
     • Erikson & Piaget - Proponents of Stages
       • All people follow the same sequence or order.  trust vs mistrust autonomy vs shame/doubt intimacy vs isolation generativity vs stagnation
   • Active or Passive? Role by Individual
     • Behaviorists believe developmental change is caused by events in the environment that stimulate individuals to respond, resulting in the learnt changes in behaviour that make up development.
     • Erikson & Piaget
       • Piaget = changes depend on person's active efforts to master new problems of increasing difficulty.  Erikson theory of identity development proposes that an individual's personality and sense of identity are strongly influenced by their active efforts to master the psychological and social conflicts of everyday life.
   • Broad or Narrow?
     • How broad are the contexts that are used to determine developmental influence

3. Psychodynamic Development Theories

   • Freud
     • A child's development is thought to occur in a series of stages. At each stage, the child experiences unconscious conflicts that they must resolve to some degree before going on to the next stage.  Freud proposes that unconscious forces act to determine personality and behaviour as individuals resolve conflicts between biological drives and social expectations. 
     • Id = present at birth and is unconscious - impulsive to satisfy a person's inborn biological needs and desires by motivating behaviours that maximise pleasure and avoid discomfort. Newborn is all 'id' pleasure principle.  Ego = rational, conscious, problem solver - related to sense of self. reality principle. Learning to delay gratification Superego = moral and ethical component of personality. Includes sense of conscious that emerges in the child. Right/Wrong and ego-ideal "how I should behave". Punishes bad behaviour with guilt, rewards good behaviour with heightened self-esteem. Provides a standard 
     • Psychodynamic Development is
       • Active
       • Dynamic
       • influenced by biological drives
       • Conscious & Unconscious social and emotional experiences
     • See notes
     • Id, Ego, Superego
     • Psychosexual Stages
       • Stages occur, and at each stage, changes result from conflicts between id, ego, superego which can be threatening to self-esteem & ego. 
       • See Table 2.1, p.38
       • Anal
         • 1-3 years old. Anus - elimination/toliet training. Toddlers may enjoy holding and releasing feces/urine.
       • Phallic
         • 3-6 years - genitals are focus. Gender roles and moral development are central.  -Oedipus complex - Boys -Electra complex - Girls Sexual desire for opposite sex parent, hostility for same-sex parent. Formation of superego and feelings of guilt formed.
       • Oral
         • Birth - 1 year - Mouth - pleasure from oral activities - can lead to thumb sucking, nail biting, pencil chewing, over eating if need is not met as infant
       • Latency
         • 6-12 years. Suspension of sexual activity. Energy shifts to physical, social and intellectual activities. Social values from adults and same-sex peers outside family are acquired. 
       • Genital
         • 12-adulthood. Genitals are focus of stimulation with onset of puberty. Sexual impulses from  phallic stage re-emerge, mature sexual relationships develop and extend through adulthood. 
     • Defense mechanisms
       • Unconscious distortions of reality that keep conflicts from the ego's (self's) conscious awareness. 
       • Repression
         • Unacceptable feelings and impulses are forced from memory and forgotten. 
       • Projection
         • A person's conflict-producing feelings, like aggression, are mistakenly attributed to another person. 
       • Unresolved Conflicts
         • conflict between id-ego or super-ego lead to fixation
         • Fixation
           • a blockage in development and can result from unresolved conflicts or from parenting that is not responsive to a child's needs. Thus, an individual's personality may reflect patterns that are typical of that stage as adults at the stage in which the fixation occurred. . 
     • Criticisms
       • Overemphasis of sexual feelings on an individual's development and based on a 19th century Victorian era and does not apply to other cultures. Freud did not directly study children. Not easily tested by scientific investigation.
   • Erikson
     • Less emphasis on biological drives and unconscious conflict. More focus on development of sense of identity as a result of important social, emotional and cultural experiences. 
     • Psychosocial theory of Development
       • Personality development is a psychosocial process meaning internal psychological factors and social factors are very important. through the development of a unique personality, social skills will contribute to our understanding of ourselves. 
       • Internal Psychological Factors
         • 1. Biological and physical strengths and limitations
       • External social factors
         • Social skills and attitudes contribute to our understanding of ourselves as members of society
         • 2. Unique life experiences & developmental history
           • Including early family experiences & degree of success in resolving earlier developmental crises
         • 3. Social, cultural and historical forces at work
           • i.e. racial prejudice, poverty, rapid technological change, or war
       • See Table 2.2, p.40
       • Psychosocial Stages & Processes
         • Basic trust vs mistrust up to 18 mo.
           • Trust established by parents meeting needs. Balance of trust/mistrust result in hope. Enduring belief that needs will be met.  
         • Autonomy vs Shame/Doubt 1-2 years
           • Toddler/Pre-schooler. ability to be independent and self-directed and balance their own demands for self-control with demands of parents for control.  Shame involves loss of self-respect due to failure to meet one's own standards and those of parents.  Successful outcome is WILL - capacity to freely make choices based on realistic knowledge of what is expected and possible. 
         • Initiative vs Guilt 3-6 years
           • Initiative combines with autonomy with the ability to explore new activities with purpose. Guilt involves self-criticism for failing to fulfill parent's expectations. Virtue = PURPOSE
         • Industry vs Inferiority 7 -11 years (latency period)
           • Virtue =  Competence. Belief in self to be a member of society through competency and skills. Those lacking this will feel inferior. 
         • Identity vs Role Confusion - Teen/Adolescence years
           • Involves a reliable sense of who one is based on the roles the individual plays.  Virtue = Fidelity - ability to sustain loyalties to certain values despite inevitable conflicts and inconsistencies. Failure and role confusion can lead to anti-social behaviour, feelings of isolation and negativity. 
         • Intimacy vs Isolation 20s & 30s (early adulthood)
           • Virtue of LOVe. Develop ability to establish close relationships with others and cope w/ fear of losing their own identity and sense of self. 
         • Generativity vs Stagnation 40s to 60s (middle adulthood)
           • Virtue = CARE. Generativity is the feeling of one's work/family life, etc are personally satisfying and meaningful to future generations. Stagnation occurs when life no longer seems purposeful. 
         • Ego integrity vs Despair 60s upwards (old age)
           • Virtue = WISDOM. Ego integrity refers to ability to look back on the strengths and weaknesses of one's life with a sense of dignity, optimism and wisdom. 
     • Epigenetic Principle
       • Underpins the ssstages of psychosocial development - which states that we develop through a predetermined unfolding of our personalities in 8 stages. Anything that grows has a ground plan and that out of this plan the parts arise each part having its time of special ascendency until all the parts have arisen to form a functioning whole. 
   • Object Relations
     • Mahler
       • During the first three years of life, children go through four phases in developing a psychological sense of self. 
       • Autistic phase, birth- 2 months
         • self-absorbed, little psychological awareness of the world - safe, sleeplike transition into the world.
       • Symbiotic Phase, 2-6 months
         • Infant experiences themselves as completely connected with and dependent on their primary caregiver rather than as a psychologically separate person.  Development of an emotionally charged mental image of primary caregiver
       • Separation-Individual Phase, 6-24 months
         • Infants begin to develop a sense of self. Functions as a separate individual
         • Practising subphase, 10-16 months
           • Safe separation and disengagement from the primary caregiver begins to occur. 
         • Hatching subphase, 6-10 months
           • Infant responds differently to the significant primary caregiver as opposed to others. 
         • Rapprochement subphase, 16-24 months
           • Disengagement is refined in this stage. Experiments more fully with leaving and returning to the safe home base of the caregiver. 
       • Object constancy phase, 24-36 months and beyond
         • Infant achieves a more stable sense of self based on their increasing ability to form reliable mental representations of their primary care givers (called objects) and their responses to them. 
       • See table 2.3 , p.43
   • Stern
     • Emergent self
       • regulation of sleeping and eating and actively participate in their interpersonal world to a signficantly greater degree than Mahler proposed
     • Core self
       • Based on an infant's awareness of being physically separate from others, emerges between two and six months of age. 
     • Subjective self
       • Based on an organised mental representation of relationships with others, appears between six and 12 months. 
     • Verbal self
       • Emerges between 12-18 months w/ development of language and symbolic thought. 
   • Application of Psychodynamic Developmental Theories Thru the Lifespan
     • Attachments as infants
     • Autonomy & self-control thru toddlerhood
     • Intimate relationships as teens/adults

4. Behavioural Learning Theories

   • Pavlov
     • Classical Conditioning
       • Pavlov rang a bell before feeding the dog. Dog slobbered in anticipation whenever it heard the bell, even if it heard no food.
       • Unconditioned response
         • Food stimulus = Unconditioned response 
       • Conditioned Response
         • Slobbering = conditioned response.
       • Unconditioned Reflex
         • Connection between food stimulus and response is an unconditioned reflex - involuntary reaction similiar to eye blink and kneejerk startles. 
     • See Figure 2.1, p. 45
     • J.B. Watson
       • Inspired by Pavlov - conducted experiment making a baby scared of rat by pairing it with a loud, scary noise, turning the child off the rat.  Environment is a critical influence upon development and adults can shape a child's behaviour by controlling stimulus-response associations. 
   • Skinner
     • Operant Conditioning
       • Reinforcement
         • Process by which the likelihood that a particular response will occur again increases when that response is followed by a certain stimulus. All about Increases
         • Positive Reinforcement
           • Occurs when, following a particular response, a rewarding stimulus is given that strengthens the response and increases likelihood it will occur again. 
         • Negative Reinforcement
           • Also strengthens a response and increases the chance of occurrence, but does so by removing an undesirable or unpleasant stimulus following the occurrence of that response - Negatively reinforcement is usually unwanted - such as giving a child a lolly to stop throwing a tantrum - it negatively reinforces that tantrums are okay. 
       • Punishment
         • weakens or suppresses a behavioral response by either adding an unpleasant stimulus or removing a pleasurable one.  All about Decrease. 
         • Shaping
           • Occurs when a child learns to perform a new responses not already in their repertoire, or collection. This is achieved by starting with an existing response, then modifying or shaping it by reinforcing small changes that bring it closer to the desired behaviour. 
         • Extinction
           • refers to the disappearance of a response when a reinforcer who was maintaining it is removed.  Best by ignoring the undesired response and rewarding an alternative. 
   • Behaviour Modification
     • a set of techniques that is basedon operant conditioning and social cognitive learning  used to eliminate undesired behaviours and increase desirable ones.  Helpful for ADHD, eating disorders (Bulimia & anorexia), as well as aggression, fear and language delays.  CBT is another way to treat some of these issues.

5. Social Cognitive Learning Theory

   • Useful in explaining gender development, aggression development, and impact of tv and media on development, as well as treating problems in children with behaviour difficulties. 
   • Bandura
     • Observational Learning
       • Leaning through observing others.  AKA: Social learning theory or Social cognitive theory. 
       • Modelling
         • Child learns behaviours and personality traits of a parent or other model through vicacrious, indirect, reinforcement.  A child learns to behave in a similiar way to those of the model by merely observing the model recieve reinforcement for their actions. 
         • Model's Influence
           • Influence of a model depends on various factors, including relationship to the child, personal characteristics and how the child perceives them.  Children's levels of cognitive development strongly influence their ability to observe, remember and later perform in ways similar to the  models they have watched. 
           • Model's Characteristics
             • More likely to model high-status, powerful, competent individuals
           • Observer's Characteristics
             • those who lack status and power are most likely to model children or adolescents 
           • Consequences of Behaviour Modelled
             • The greater the value the observer places on the behaviour, the more likely it is the behaviour will be modelled. 
       • Reciprocally determined
         • Learning is a result of interactions between the developing individual - including their behaviours, cognitive processes, and physical capacities - and their physical and social environment. 
       • Imitation
         • A child is directly reinforced for repeating or copying the actions of others. 
       • Stages of:
         • 1. Attend to the model
           • We need to attend to the behaviour of the model if we are to model, memorise and reproduce the behaviour. 
           • 2. Remember the details
             • Remember characteristics of the behaviour and what is seen and heard if we are to reproduce it later. 
           • 3. Reproduce the behaviour
             • Reproduce the memory or the behaviour of the model that was observed and imitated
         • 4.Receive reinforcement for behaviour

6. Cognitive Developmental Theories

   •  These theories have a strong focus on how thinking and problem-solving skills develop and how such cognitive activities contribute to the overall process of development
   • Piaget's Cognitive theory
     • Cognitive Stages
       • See table 2.4, p.48
       • Sensorimotor, 0-2 years
         • Coordination of sensory and motor activity. Infants use hands eyes and ears to invent ways of problem solving sensorimotor issues. begin to develop knowledge of the world through senses
         • Object Permanence
       • Preoperational, 2-7 years
         • Use of language and symbolic representation; egocentric view of the world, make-believe play. Thinking lacks logic
         • Lack of logic; Egocentric
       • Concrete Operational, 7-11 years
         • Solution of concrete problems through logical operations; objects are organised into hierarchies and classes and subclasses; thinking is not abstract yet. 
         • Hierarchies; Non-Abstract thoughts
       • Formal Operational, 11-adult
         • Abstract & systematic thought
     • Developmental Proccesses
       • Assimilation
         • New problems are solved using existing schemes
       • Accommodation
         • Existing schemes are altered or adapted to meet new challenges.
       • Equilibrium
         • creates a state of cognitive balance.
       • Direct Learning
         • Results when a person actively responds to & interprets new problems and experiences based on thoughts and actions they already know, called Schemes.
         • Scheme/Schemata
           • A systematic pattern of thoughts, actions and problem-solving strategies that helps the individual deal with a particular intellectual challenge or situation  - a way to make sense of our world and experiences through an organized structure.  Change rapidly as infant gains new experiences through processes of assimiliation and accommodation
           • Innate Schemes
             • A newborn has a limited number of these built in that include unlearned reflexes that are active at birth - sucking, grasping
       • Developing through stages of thought
         • 1. Direct Learning
           • Adaption
             • Development results from the interplay between assimiliation and accommodation, a process called adaptation. 
         • 2. Social transmission
           • A second explaination for development, is the process through which one's thinking is influenced by learning from social contact with and observation of others, rather than through direct influence.
         • 3. Physical maturation
           • Referring to the biologically determined changes in physical and neurological development that occur relatively independently of specific experiences. 
     • Criticisms of Piaget
       • 1. How to explain why children master tasks that are logically equivalent at very different points in their development.  2. Difficult to explain why a child's cognitive performances on two logically similiar tasks are often very different.  3. Exclusive emphasis on the pre-determined 'logical' aspects of children's thinking often do not match the thought processes children appear to use.  - It also ignores the social, emotional and cultural factors that influence the process. 4. Fails to recognise cognitive development continues after adolescence. 
     • Piaget
       • Development is universal
         • Western cultures
   • Information Processing Theory
     • Focuses on the precise, detailed features or steps involved in mental activities. Like a computer, the mind is viewed as having distinct parts that make unique contributions to thinking in a specific order. 
     • Info take in thru person's senses
       • Info is seen to flow thru info-processing system
         • Info is coded, transformed & organised
           • Held in sensory register
             • First memory store (or sensory memory) records information exactly as it recieves it, but the information fades or disappears within a fraction of a second unless the person processes it further. Organisation is necessary. 
             • Attention
               • Ability to focus on cognitive processes such as perception, thinking and memory on a particular task. It includes selective attention.
               • Selective attention
                 • What a person responds to attentively depends on their interests and individual needs) 
               • Attention span
                 • The length of time a person can focus their attention on a particular object or task
             • Perception
               • involves sensory input and the interpretations given by the mind. it is through perception that people develop meaningful experiences
               • Short-term Memory
                 • Information to which a person pays special attention is transferred to short-term memory. the second memory store. Can only hold a limited amount of information. 
                 • 2nd memory store
                 • Can hold approx 7 pieces of information
                 • After about 20 seconds info in STM is forgotten or lost unless something is done with it.
                   • Long-term Memory
                     • More time and effort are required to move information into LTM. capacity is unlimited for all practical purposes. Once info is secured there, it remains there, although accessing it can be problematic at times. 
                     • 3rd memory store
                     • Recognition
                     • Recall & reconstruction
                       • which are significant in enhancing memory to receive new information.
                     • See figure 2.2, p.51.
                   • Rehersal
                     • Repeating information in STM to keep it available.. A control process that affects the flow of information through the information processing system.
                 • Working memory
                 • Control Processes
                   • As children get older, they gain acquisition of control processes which direct a person's attention towards particular input from the sensory register and guide the resposne to new information once it enters the STM.  Control processes organise information in STM. 
                   • Metacognition
                     • An awareness and understanding of how thinking and learning work. Assists learning in a number of ways: 1. Allows a person to assess how difficult a problem or learning task will be and to plan appropriate ways to approach it.  2. Involves knowledge of self, knowledge of task variables, and knowledge of which information-processing strategies are effective in different situations. 
                     • Knowledge base
                       • referring to a child's current fund of knowledge and skills in various areas. A child's knowledge base in one area makes acquiring new information and skills in the same area easier, because the ch ild can relate new info to prior info more meaningfully. 
             • 1st memory store
     • Gagne's Info-Processing Model
     • Not stage-like, but continuous development, gradually.
   • Neo-Piagetian Theories
     • Case
       • Increase in mental space capacity for schemes as a child ages
         • In childhood, most structures are concrete and specific. As the structures become coordinated w/ one another, the form higher-level cognitive structures. 
     • Fischer
       • Skills rather than Schemes
         • Use of skills to describe cognitive structures that children use in particular problem-solving tasks or sets of tasks. The breadth of a skill  is determined by the level of maturation in the child's CNS and the range of specific learning environments to which the child has been exposed.  Support by parents, teachers plays a role in acquisition of skills. 
         • 'Breadth of skill' links to Vgotsky's 'Zone of Proximal Development'
   • Crystalised intelligence
     • includes learned cognitive processes and abilities such as vocabulary, general information and word fluency improve with age
   • Fluid intelligence
     • Ability to process new information in novel situations peaks in adolescence and decreases with age
   • Cognitive mechanics
     • Intellectual problems in which culture-based knowledge and skills such as reading, writing, language comprehension and professional skills are primary, can help people in their 70s maintain and even improve their memory.  

7. Contextual Developmental Theories

   • View development as a process of reciprocal, patterned interactions between the individual and their physical and social environment
   • Brofenbrenner's Ecological Systems Theory
     • Proposes a person's development is influenced by four active and overlapping contextual labels.  Brofenbrenner saw the environment as an ever changing system 
     • Microsystem
     • Mesosystem
     • Exosystem
     • Macrosystem
     • Environment not static
     • See Mod 1, Ch 1 notes
   • Vygotsky's Sociocultural Theory
     • Marxist Russia. Interested in how changing historical and cultural contexts within which children's activities occur influence their cognitive development. Higher mental functions grow out of the social interactions and dialogues that take place between a child and parents, teachers and other representatives of the culture. Through these interactions, children interalise increasingly mature and effective ways of thinking and problem solving. Some of these changes occur through discoveries that the child initiates on their own. 
     • Zone of Proximal Development
       • Refers to a range of tasks that a child cannot yet accomplish without active assistance from adults and peers with greater knowledge and the framework of support and assistance called scaffolding
       • Scaffolding
         • Scaffolding is provided by adults and more able peers who provide support, assistance and facilitation of learning within the individual's current level of performance. As the individual's competence develops, support is gradually withdrawn, turning responsibility over to the individual. 
     • Development is 'context-specific'
       • It must be understood in terms of the particular social, cultural and historical processes of people's everyday lives/experiences. These different influences change how a person may solve problems.
       • Non-western cultures
   • Lerner
   • Elder
     • Social Trajectories
       • .Pathways that guide individual development. Cross cultural research indicates that different aspects of behaviour are emphasised differently in different cultures. 
       • Human Agency
         • Freewill
   • Ethological theory
     • Studying how differences in temperment that are observable at birth contribute to development through childhood and adolescence. It also contributed to the study of the role of attachment playing in the development of relationships from infancy thru the lifespan.  Has roots in animal study. - emphasizing the ways behaviours have survived and evolved in different developmental contexts through the process of natural selection & adaptation to ensure the survival of the species. 
     • Temperment
       • Attachment
     • Applies the principles of
       • To behavioral and psychological characteristics. 
       • Evolutionary Biology
         • Ethology
     • Imprinting
       • Imprinting takes place at a critical point of development. Animals will imprint onto whomever they encounter first to keep them safe from danger. 
     • Lorenz
     • Tinbergen

8. Adulthood and Lifespan Development Theories

   • Normative-crisis model of development
     • Assumes developmental change occurs in distinct stages, which individuals follow in the same sequence. each successive stage is qualitatively unique from all other stages and is increasingly more complex and more fully developed and integrates the changes and accomplishments from earlier stages.  Shares a focus with psychodynamic theories on the importance of impulses within the individual that lead to developmental change. 
     • Partly influenced by biologically drive maturational changes
       • Hall -> Gesell
         • Maturational Theory of Development
           • Seen to be intrinsically guided by genetic endowment and predetermined by a sequential unfolding of patterns and configurations. Most important issue for developmental psychology was to describe the normal or average characteristics of children at any age. 
           • Erikson (Ch 1)'s Psychosocial Theory is a good example
   • Vaillant
     • Concluded that development is a lifelong process that is influenced mainly by relationships with others and by adaptive mechanisms or 'coping styles' that people use to deal with life events.  Mature coping styles include sublimation (redirecting anxiety and impulses towards better goals) & altruism. The use of mature coping styles increase with age and most likely to occur in people who have healthy brains and have experienced loving relationships. . 
     • Age of establishment, 20-30 years
       • Autonomy from parents, marriage, parenthood, establishing more intimate friendships
       • Career consolidation, 20-40 years
         • Consolidating & strengthening marriage & career; devotion to hard-work and career advancement
         • Midlife transition, 40-50 years
           • Reassessment & reordering of experiences of adolescence and young adulthood. Heightened self-awareness and exploration of forgotten inner self opening the way for achieving greater generality. 
           • Midlife, 50 years and older
             • Leaving behind compulsive involvement with occupational apprenticeships; becoming increasingly self-reflective, nurturant and expressive. 
       • Phases of adult-development
     • See table 2.5, p. 57
     • Coping Styles
       • Adaptive mechanisms that people use to deal with life events like sublimation & altrusim
   • Levinson
     • Eras of adult development
       • Early adulthood,
         • Middle adulthood
           • Late adulthood
             • Late adult transition
           • Early life structure
           • Age 50 transition
           • Culminating life structure
         • Early adult transition
         • Childhood - adolescence
           • birth - 17 years of age
         • Early Life Structure
         • Age 30 Transition
         • Culminating life structure
         • Midlife transition
       • See table 2.6, p. 58
   • Timing of Events Model
     • Views life events as markers or indicators of developmental change. Life events can be normative or non-normative. 
     • Life Events
       • Reflects an awareness of two important ways in which capabilities, life experiences and developmental changes of adulthood tend to differ from those in childhood/teen years: 1st: The changes during adult years are less tied to predictable physical and cognitive maturational changes from childhood/teen years - rather seem to be more linked to social and psychological conditions, events and experiences that adults encounter. 2nd: Physical, cognitive and psychosocial competencies of adults allow them to play a much more active and self-conscious role in directing their own development through the decisions and choices they make. Such as when to marry, political affiliation, religions decisions can all affect development. 
       • Normative
         •  Transitions that follow an age-appropriate social timetable; individuals create an internalised social clock that tells them whether they are on time in following that schedule i.e. marriage, parenthood, career, physical decline, retirement, widowhood, etc. 
         • Social Clock
       • Non-normative
         • Most life events are non-normative and less predictable. It can occur at any point in time in a person's life and may include normative events that occur 'off-time' such as marrying 'late'. 
   • Dynamic Systems Approach
     • Dynamic systems theorists view the child's mind and body as well as their physical and social worlds as forming an integrated system which guides the development and subsequent mastery of new skills. this system is seen as dynamic; that is as one constantly in motion and moving...not static. 
     • Dynamic, not static.
     • Any change in one part of the system impacts on the integrated system and influences the individual-environment relationship
     • Includes individual differences
       • Biological & social support
     • Thelan
     • Fischer

9. see Table 2.7 for Comparison of Developmental Theories, p. 60