It is possible that domain-specific mechanisms designed by natural selection to deal with specific aspects of the physical or social environment (e.g. face recognition) evolved, though domain-general mechanisms are also likely to exist as a result of evolution (e.g. executive function). Constraints limit the type of information that can be processed and the way this can be processed. There are three types of constraints on learning:

1. Architectural constraints (i.e. biology of the brain)
   This refers to the way the brain is organized at birth (e.g. neuronal make-up).
2. Chronotopic constraints (i.e. maturational constraints)
   This refers to the developmental stage a person is in (e.g. puberty). Brain areas may be sensitive to certain types of learning during a particular timeframe.
3. Representational constraints
   This refers to hardwired representations in the brain (i.e. innate knowledge) which guides and constraints learning (e.g. basic knowledge of objects).

Evolved probabilistic cognitive mechanisms refer to information-processing mechanisms that have evolved to solve recurrent problems faced by ancestral populations. This will develop in a species-typical manner if the individual experiences a species-typical environment (e.g. innate readiness to be afraid of snakes but no innate fear of snakes).

Geary states that the mind is a set of hierarchically organized domain-specific modules that develop as children engage their physical and social worlds. Development finetunes these modules as these are very flexible and broad (i.e. adaptive). The long period of immaturity of humans may be necessary to master the complexities of human society and technology (i.e. cognition needs to be adapted to a wide range of environments).

There are biologically primary abilities (e.g. language):

• This has undergone selection pressure and has evolved to deal with problems faced by our ancestors.
• This is acquired universally in all but the most deprived environments.
• Children tend to reach an expert level of proficiency.
• Children are intrinsically motivated to exercise these abilities and do so spontaneously.

There are also biologically secondary abilities (e.g. reading):

• This does not have an evolutionary history but is based on biologically primary abilities.
• This is culturally dependent (i.e. it reflects cognitive skills that are important in a culture).
• Children are not intrinsically motivated to learn this.
• Children may need tedious practise to achieve mastery.

A dynamic system refers to describing how a state develops into another state over time (e.g. butterfly effect). A system (e.g. a child) refers to a collection of components that are connected. In a dynamic system, all these components are changing and influencing each other. Dynamic systems theories state that change is equal to development. According to these theories, variation in factors (e.g. childhood environment) leads to changes in development. This leaves space for individual differences.

The developmental systems approach states that development depends on the interaction at all levels between the environment and genes (i.e. epigenesis). New structures and functions emerge during development as a result of self-organization through bidirectional interactions of elements at various levels of organization (e.g. genes; environment).

Epigenesis refers to the expression of genes that depends on the interaction with its environment. This is an example of a complex interaction between genes and the environment illustrating a dynamic system (e.g. gene influences environment and vice versa). Genes are expressed differently in different environments but people still develop in a species-typical way as there is a species-typical environment.

The timing of a particular event can influence what effect that event will have on development. The sensitive period (i.e. critical period) refers to the period in development when a particular skill (e.g. language) is most easily acquired. The presence and absence of experience can play a big role in a sensitive period (e.g. absence of fine-tuned perceptual system prevents sensory overload which leads to a better understanding of the world). The timing of events may be inherited and this may give rise to species-typical patterns of brain and cognitive development (i.e. instinctive behaviour).

The genotype -> environment theory states that genes drive experience. The genotype influences what environment one encounters and the type of experience one has. A child’s phenotype is influenced by the genotype and the environment. A parent’s genotype and the rearing environment also influence a child’s phenotype.

There are three types of genotype -> environment effects:

1. Passive effects
   This occurs when the parents provide both the genes and the environment. This effect decreases over time.
2. Evocative effects
   This occurs when child characteristics elicit reactions from others. This effect is constant with age.
3. Active effects
   This occurs when a child seeks an environment that is appropriate to its genotype. This effect increases with age.

The process of myelination increases throughout childhood and adolescence. It proceeds at different rates for different brain areas. Neurons go through three stages of development:

1. Proliferation (i.e. neurogenesis)
   This is the process of production of new neurons through mitosis. It mostly occurs early in development during the prenatal period.
2. Migration
   This is the process of moving the neurons to their permanent position in the brain. This is mostly finished by the age of 7 months. A faulty migration is associated with disorders (e.g. epilepsy).
3. Differentiation
   This is the process of growing in size (1), producing more dendrites (2), extending their axons (3) and creating synapses (4). Most of this process takes place after birth.

Synaptogenesis is rapid during the early years of life. The number of synapses reduces as a result of experience pruning (i.e. apoptosis). The process of rapid development followed by decline occurs in multiple areas of brain development (e.g. brain metabolism).

Hypermetabolism of the brain may be necessary for rapid learning in early life. The increase in the number of neurons and synapses compared to adults may allow for more brain plasticity. However, failure of apoptosis is associated with disorders (e.g. schizophrenia). A rapid growth and rapid apoptosis may be associated with the best developmental outcomes.

There is a reciprocal relationship between brain and behavioural development. Specific experiences may produce neural activity which determines which of the excess synapses will remain. Experience-expectant processes (i.e. experience-expectant synaptogenesis) refers to the processes whereby synapses are formed and maintained when an organism has species-typical experiences. Experience-dependent processes (i.e. experience-dependent synaptogenesis) refers to processes in which connections among neurons are made after the unique experiences (i.e. non-species-typical experience) of an individual rather than a species-typical experience.

The early plasticity view of brain damage states that brains of young children are highly plastic relative to adults and this allows them to better overcome the effects of brain damage. The Kennard effect states that a younger brain is more likely to recover normal function than an older brain. However, this does not hold for all types of brain damage (e.g. very early brain damage).

Recovery of brain damage depends on injury factors (1), age factors (2), environmental factors (3) and the type of rehabilitation (4). There is often greater recovery when a more general cognitive function is damage (e.g. executive function). Extended immaturity of the human nervous system allows for resilience (1), behavioural flexibility (2) and plasticity (3).

Gene-environment correlation states that people with more similar genes experience more similar environments and vice versa. Transactional models state that early-life behaviours, driven by genetics, lead to a person selecting particular types of environments. This, in turn, has a causal effect on cognition (e.g. having higher IQ leads to environments where you can stimulate IQ which leads to an even higher IQ).

The Matthew effect refers to problems becoming larger as a result of the initial problems. For example, limited vocabulary will lead to reading difficulties which, in turn, lead to an even more limited vocabulary. This effect emphasizes the importance of initial individual differences in later life outcomes.

The availability of environmental experiences is essential in choosing one’s environment. Differences in heritability could thus demonstrate important underlying developmental processes. Heritability increases with age as people select their own environment. It could also be that heritability increases with age because new genes become activated later in development (e.g. biological changes of puberty).

For children with a low SES, the heritability is not as high as for children with high SES. This may be because of the limited options that these children have. Genes limit the environment but the environment also limits gene expression (e.g. SES). Genes and the environment influence each other.

Parents teach their children norms and values through parenting. This also has an educational goal (e.g. socializing children). This depends on the parents’ involvement in work (1), school functioning (2) and parental monitoring (3).

The parental belief systems influences parental rearing practices. This, in turn, influences child behavioural development and child belief systems. The main dimensions of parenting are responsive vs. unresponsive parenting and not demanding vs. demanding parenting.

There are several parenting styles:

1. Authoritative (i.e. high on responsiveness; high on demanding)
   These children are often the most competent (1), independent (2), self-controlled (3) and achievement-oriented (4).
2. Authoritarian (i.e. low on responsiveness; high on demanding)
   These children are often socially incompetent (1), more dependent (2) and are used to challenges (3).
3. Permissive (i.e. high on responsiveness; low on demanding)
   These children are often without goals (1), not assertive (2) and not performance-oriented (3).
4. Neglectful (i.e. low on responsiveness; low on demanding)
   These children have severe consequences in their cognitive and socio-emotional development.

The authoritative parenting style may be related to positive outcomes because of high emotional safety and parents providing explanations that lead to awareness and understanding. There is higher autonomy for the children and decisions are more democratic. This bi-directional communication with children may promote social skills which, in turn, promote positive experiences at school.

Parents can make use of control techniques to ensure compliance. Compliance is important for family well-being and functioning and non-compliance predicts behavioural problems (1), poor relationships (2) and delinquency (3). However, some form of non-compliance is normal and may help the child with its development. There is a difference in compliance when children adhere to norms or when they internalize the norms.

High-power control techniques include coercion (1), threat (2), physical interventions (3) and anger. This increases reactance. Effective control techniques include maintaining a warm and supportive relationship. It is important to allow the child to have some control in the interaction.

There are two broad dimensions of parenting:

1. Parental support
   This refers to the affective nature of the parent-child interaction. This includes showing involvement (1), acceptance (2), emotional availability (3), warmth (4) and responsivity (5).
2. Paternal control
   
   1. Behavioural control
      This refers to behaviours aimed at controlling, managing or regulating the child’s behaviour through enforcing demands and rules (1), disciplinary strategies (2), punishment (3) or supervisory functions (4).
   2. Psychological control
      This refers to behaviours aimed at manipulating children’s thoughts, feelings and emotions.

Parental support is associated with positive developmental outcomes. Behavioural control is associated with positive developmental outcomes when the behavioural control is not excessive whereas psychological control is associated with negative child outcomes.

Children in two-parent households are influenced by the parenting style of both parents but also by the interaction between these styles (e.g. additive effect of two authoritative parents). Kuppens & Ceulemans found several other parenting styles:

1. Congruent authoritative parenting style
   This refers to a parenting style where both parents use the authoritative parenting style.
2. Congruent positive authoritative parenting style
   This refers to a parenting style where both parents use the authoritative parenting style but there rarely is any disciplining of the child.
3. Congruent authoritarian parenting style
   This refers to a parenting style where both parents use the authoritarian parenting style.
4. Congruent intrusive parenting style (i.e. uninvolved parenting)
   This refers to a parenting style where both parents do not show warmth or involvement and do not set clear rules or discipline the child. There are elevated levels of psychological control.

Inadequate behavioural control and psychological control are associated with each other (e.g. harsh disciplining and psychological control often co-occur or precede one another). Parents who engage in psychological control may desire to fulfil their own needs by applying controlling behaviours with their children.

Belsky states that parenting is influenced by factors of the parent (1), factors of the child (2) and the family social context (3). Positive parenting refers to dimensions of parenting such as warmth (1), sensitivity (2), limit setting (3), appropriate scaffolding (4) and contingency-based reinforcement (5). Negative parenting refers to behaviours that are inconsistent (1), overreactive (2), controlling (3) and harsh (4).

The parenting of fathers is subject to contextual influence and has a great impact on child outcomes. There are three primary predictors of parenting:

1. Developmental history
   This may predispose the parent to have certain traits which impact the ability to parent (e.g. intergenerational transmission o parenting).
2. Personality
   
   1. Extraversion
      This is associated with high levels of energy (1), sociability (2), response to reward (3) and optimism (4). It may lead to more sensitive and responsive parenting but the limited verbal ability of a child may lead to maladaptive outcomes due to the social desires of the parents. This may negatively impact fathers but not mothers.
   2. Agreeableness
      This is associated with cooperativeness (1), trustfulness (2), prosocial behaviour (3) and a willingness to compromise (4). It is associated with positive parenting because these people have a high investment in maintaining close social relationships and may be a protective factor against a mother’s likelihood to engage in harsh parenting.
   3. Conscientiousness
      This is associated with being organized (1), dependable (2), responsible (3) and orderly (4). This may aid parenting although extremely high levels of conscientiousness may be detrimental due to the discrepancy between the desire for order and the chaos of a child.
   4. Neuroticism
      This is associated with being anxious (1), insecure (2) and emotionally unstable (3). It is negatively associated with adaptive parenting behaviours. Parents may focus on their own distress and this may impair the ability to respond sensitively to the need of the child. It may impact mothers more than fathers.
   5. Openness
      This is associated with originality (1), imagination (2), open-mindedness (3) and broad-ranging interests (4). This may lead to sensitive parenting through the desire for new activities but may conflict with the need for repetitive tasks of parenting.
3. Psychopathology
   Depression is associated with impaired parenting as it compromises cognition (1), behaviour and affect (3) which leads to a neglect of the child’s socio-emotional needs. Rumination may leave little mental space for the child’s perspective. It leads to lower positive parenting (1) but also to lower quality mother-child interactions. The impact of depression depends on the chronicity and the timing of the episode. The impact is larger during infancy and early childhood.

Mother’s sense of efficacy and parenting-related knowledge influences the effectiveness of parenting. Personality influences parenting-related cognition and this influences parenting practices. Extraversion in mothers may function as a support mechanism as these social networks are more likely to be focused on parenting. This may not be the case for fathers, leading to negative child outcomes. It is possible that this only occurs for children that have low effortful control. The opposite pattern may exist for high effortful control.

Disengaged parenting refers to non-involvement (1), unresponsiveness (2), flat affect (3) and few vocalizations (4). Technoference refers to interruptions in parent-child interactions caused by technology. Emotional flooding refers to when one perceives their interaction partner’s negative affect as overwhelming and engages in an escape response. This may lead to harsh discipline practices.

The interaction style with a child is moderated by parent characteristics (1), child characteristics (2) and culture (3). A parent’s characteristic involves personality or temperament and the sex of the parent. A child’s characteristic involves personality or temperament and abnormalities (e.g. disability).

There are also cultural differences in interaction style. The interaction style depends on the cultural constraints put on the caregiver (e.g. mother in Kenya emphasizes physical touch and avoids gaze because a quiet child is necessary to return to work in the field).

Temperament refers to biologically-based differences in reactivity and behavioural style that are detectable in very early childhood. There are three dimensions of temperament:

1. Surgency (i.e. approach behaviour)
2. Effortful control (i.e. attentional focusing and inhibitory control)
3. Negative emotionality (i.e. tendency to react to stressors with high levels of emotionality such as irritability).

Negative emotionality may make a child more difficult to parent, eliciting negative parental behaviours. This may depend on the parent’s perception of the child’s difficulties. Mother’s tend to have a lower sense of efficacy when perceiving NE than fathers. The interaction hypothesis states that the impact of the child NE on parenting is dependent on the characteristics of the caregiver and the caregiver environment. A high SES may be a protective factor against NE.

The main effect model of social support states that social support positively impacts parenting regardless of context. The buffering effects model of social support states that social support has a greater impact on mother’s parenting who are experiencing more contextual stressors (e.g. poverty). The quality of social support may also be important. Socioeconomic status may increase the strength of associations between contextual factors and early childhood parenting.

Marital quality consists of marital satisfaction and marital conflict. The compensatory hypothesis states that parents turn to the parent-child relationship to fulfil needs that are not being met int heir marriage. The spillover hypothesis states that parents in happy relationships will be better equipped to respond with warmth and sensitivity to their children. The latter hypothesis is favoured by research.

The fathering vulnerability hypothesis states that the parenting of fathers is susceptible to distress because fathers are less able to compartmentalize emotion and insecurities. This leads to a spillover of negativity during interactions with their children. This means that marital relationship may have greater impact on paternal parenting. Marital conflict is more strongly associated with parenting of daughters compared to sons (e.g. higher paternal warmth). Marital quality may have the biggest effect on non-matching gender (e.g. father; daughter).

A child’s first relationship (i.e. with the caregiver) is prototypical for future relationships. There are five stages of early interactions:

1. Biological regulation (birth)
   This entails regularizing basic biological processes (e.g. feeding) in synchrony with parental requirements. In this stage, rhythms emerge quickly (e.g. sleep pattern).
2. Face-to-face exchanges (2 months)
   This entails regulating mutual attention and responsiveness in interactions. This develops in line with the beginning of visual control.
3. Topic sharing (5 months)
   This entails incorporating objects into social interaction. This includes external topics in the interaction but there is no simultaneous attention (i.e. attention is focused on one object at a time).
4. Reciprocity (8 months)
   This entails initiating intentional actions and more symmetrical relationships. There is more joint coordination and it starts to resemble a linguistic conversation. The child starts to show intentionality (e.g. planned behaviour).
5. Symbolic representation (1.5 years)
   This entails developing non-verbal and verbal symbolic means of relating to others. The child develops gestures for symbolic representation and there is rapid language development.

Feeding helps with the biological regulation stage as it leads to early synchronization of turn-taking. After three months, a child only has regulation of attention whereas it has manipulative skills for objects at five months. A child will only smile at familiar faces at 7 months of age and this fosters the relationship between the infant and the caregiver.

In the topic sharing stage, the direction of gaze is a signal for the caregiver to focus attention. Joint involvement episodes refer to periods of common attentional focus. The caregiver is often verbal during these periods and this helps build the child’s vocabulary. In young children, gestures have the function of representing objects (1), requests (2), attributing a characteristic (3), replying (4) and indicating events (5).

There are complex interrelationships between biological, psychological and socio-contextual processes. The family is the primary context for children’s development. In the system of family, there are several subsystems (e.g. relationships between individuals) meaning there is a circularity of influence. The system is also influenced by external factors and thus subject to change.

The lifecycle of a family consists of major events which impact the system of the family significantly:

1. Living together until the birth of the first child.
2. The birth of the children.
3. Raising children until the eldest starts living on his own.
4. Children start to move out.
5. All the children have moved out.
6. A partner dies.

There are physical demands (1), emotional challenges (2), limitations of possibilities (3) and tensions in marriage (4) as a result of a new-born child in a family. A new-born child is also a great influence on older children in the family

• There are more opportunities for interactions.
• There is less time with the caregiver.
• There is more confrontation and more rules.
• There can be more disruptive behaviour (i.e. older child becomes more difficult to handle).
• There is a stimulation of social-cognitive development (e.g. theory of mind).