Developmental Psychology Studies

Correlational Studies

• Correlational studies cannot determine causation because variables are only measured, not manipulated, meaning third variables and directional causes cannot be ruled out

Observational Studies

• Structured observation occurs in controlled settings to elicit specific behaviors
• Naturalistic observation happens in real-world environments, without interference
• Structured observation provides consistency and is helpful for developmental research, especially with young children

Ethical Considerations in Developmental Research

• Working with children requires special ethical consideration, including obtaining informed consent from guardians
• Researchers need to ensure minimal risk and use age-appropriate tasks and non-invasive methods to maintain ethical standards

Experimental Studies in Developmental Psychology

• Harry Harlow's monkey studies is an example, he studied attachment in infant monkeys by manipulating the availability of a cloth versus wire mother
• This study demonstrated the importance of contact comfort in early development

Experimental vs. Correlational Designs

• If the goal is to establish cause-and-effect and it’s ethically feasible, an experiment might be used
• For long-term developmental outcomes, like the impact of early trauma, a correlational or longitudinal design is more appropriate

Bandura's Bobo Doll Study

• Bandura's Bobo Doll study is relevant to developmental psychology because it shows how children learn behaviors through observation
• Modelling in early childhood is key to understanding how social influences shape development
• Experimental designs can be adapted ethically for young participants by using structured observations rather than direct intervention

Strengths and Limitations of Structured Observation

• Structured observation allows researchers to consistently observe and record specific behaviors in a controlled setting, making results easier to compare across participants
• Structured observation is useful in developmental research where young children may struggle with self-report methods
• Limitations include behaviors observed in artificial settings may not fully reflect how children behave in natural environments, potentially impacting ecological validity

Correlational vs. Experimental Designs

• A researcher might choose a correlational design when it’s neither ethical nor practical to manipulate variables, which is often the case in developmental psychology
• Correlational designs allow researchers to study real-life variables, like parenting style or early adversity, and their relation to developmental outcomes over time
• While causation cannot be established, correlational designs are valuable for identifying patterns, risk factors, and areas for future experimental research

Genetic Variation in Meiosis

• Genetic variation is crucial because it increases the chances of survival in changing environments
• Crossing over and independent assortment during meiosis produces genetically unique gametes, which enhances species diversity and adaptability over generations

Mitosis vs. Meiosis

• Both mitosis and meiosis involve the alignment and separation of chromosomes through stages like metaphase and anaphase
• In meiosis I, homologous chromosomes, not sister chromatids, are separated, which reduces the chromosome number by half

Polar Bodies in Female Meiosis

• Polar bodies are by-products of the unequal division of cytoplasm during oogenesis
• Only one egg retains most nutrients and cytoplasm, which supports early development if fertilized
• The polar bodies usually degenerate and are reabsorbed by the body

Nondisjunction

• Nondisjunction can occur during anaphase I or II of meiosis when chromosomes fail to separate properly
• This can result in gametes with an abnormal number of chromosomes, leading to conditions like Down syndrome (trisomy 21)

Meiosis and Evolution

• Meiosis contributes to evolution by introducing genetic variation
• During recombination and the random assortment of chromosomes, offspring inherit new combinations of genes, some of which may be advantageous and passed on through natural selection

Female vs. Male Meiosis

• In female meiosis, or oogenesis, only one functional egg is produced to maximize the resources available for potential fertilization and early embryonic development
• The egg retains most of the cytoplasm and nutrients, while the other three cells, called polar bodies, receive very little and eventually degenerate
• Male meiosis, or spermatogenesis, aims to produce quantity over size, resulting in four small, mobile sperm cells designed to reach and fertilize the egg

Non-disjunction During Meiosis

• Nondisjunction is when chromosomes fail to separate properly during meiosis, either in anaphase I or anaphase II
• This results in gametes with an abnormal number of chromosomes
• If such a gamete is involved in fertilization, the resulting zygote may have a chromosomal disorder
• Down syndrome, which occurs when a person has an extra copy of chromosome 21, known as trisomy 21, is a common example

Meiosis and Genetic Diversity

• One key way meiosis contributes to genetic diversity is through crossing over, which occurs during prophase I
• Homologous chromosomes pair up and exchange genetic material
• This recombination creates new combinations of alleles, meaning that each gamete and eventually each offspring has a unique genetic makeup
• This genetic variation is crucial for evolution and adaptation

Synaptic Pruning

• Synaptic pruning is the process where unused neural connections are eliminated, which helps make the brain more efficient
• Ensures that frequently used pathways are strengthened, while unnecessary ones are removed, supporting more specialized, adaptive functioning

Experience-Expectant vs. Experience-Dependent Brain Development

• Experience-expectant development refers to processes the brain is primed to undergo, assuming typical environmental input, like exposure to language or light
• Experience-dependent development involves learning based on unique individual experiences, like learning a musical instrument
• Both shape the brain but differ in timing and universality

Myelination

• Myelination speeds up communication between neurons, which supports more complex skills
• As motor areas become myelinated, infants move from reflexes to intentional actions
• Myelination in language areas supports rapid vocabulary growth in toddlerhood

Brain Plasticity

• Plasticity allows the infant brain to adapt and recover, especially after injury or adversity
• The brain is more sensitive to negative experiences, like neglect or trauma, which can disrupt development if not addressed early

Infancy

• The brain is developing rapidly and forming foundational systems and environmental input, which can have lasting effects.
• Early intervention and supportive caregiving are crucial to promoting healthy development and preventing long-term issues

Sensitive Period for Brain Development

• Infancy is considered a sensitive period as the brain is undergoing rapid growth and has high plasticity
• Infancy is highly responsive to environmental input, both positive and negative
• Factors like drug exposure, malnutrition, or lack of stimulation during this time can significantly disrupt neurodevelopment
• These early influences can have long-lasting effects on cognitive, emotional, and behavioral outcomes

Synaptogenesis and Pruning

• Synaptogenesis is the rapid formation of new connections between neurons, especially in infancy
• Helps the brain build the foundation for learning and sensory processing
• Synaptic pruning works alongside this by eliminating connections that aren’t frequently used
• Increases efficiency and helps the brain specialize in response to the child's environment
• Together, these mechanisms support more organized and adaptive development

Brain Development in Infancy

• Understanding brain development in infancy has real-life implications for parenting, education, and healthcare
• Highlights the importance of responsive caregiving, early stimulation, and secure attachment
• Supports the need for early intervention, for example, identifying developmental delays or addressing adverse environments like neglect or poverty
• Developmental psychologists and healthcare professionals use this knowledge to guide strategies that promote optimal outcomes during this critical period

Object Permanence Development

• Development of object permanence suggests that infants are beginning to form mental representations and short-term memory
• Understanding that objects continue to exist even when unseen shows they can hold that information in mind, which is a foundation for later memory and symbolic thought

Egocentrism

• Research shows that by the concrete operational stage, children perform better on perspective-taking tasks like the three mountains test
• Children also demonstrate improved theory of mind, understanding that others have different beliefs, thoughts, and emotions, especially by around age 4 or 5

Conservation

• Conservation shows the child can understand that physical properties like volume or number remain the same despite changes in appearance
• Requires logical operations like reversibility and decentration, both signs of more advanced, rule-based thinking

Educators

• Teachers can tailor tasks based on developmental stage
• Preschoolers may benefit more from hands-on, visual learning since they're still egocentric and not yet conserving
• Older children, who can reason logically, are better able to handle abstract or rule-based content

Cognitive Shifts

• The prefrontal cortex supports executive functions like attention and perspective-taking, which relate to overcoming egocentrism
• The parietal lobes are linked to spatial reasoning and classification, which help with conservation
• Brain maturation plays a key role in progressing through Piaget's stages

Object Permanence as a Milestone

• Object permanence is a major milestone because it marks the beginning of mental representation, the ability to hold an image or concept in mind even when it’s not visible
• This is foundational for memory, symbolic thinking, and problem-solving
• Signals a shift from reflex-based behavior to more intentional, goal-directed actions, which is a key aspect of cognitive development during the sensorimotor stage

Egocentrism

• In the preoperational stage affects social interactions because children have difficulty understanding that others may have different thoughts, feelings, or perspectives
• Turn-taking, empathy, and perspective-taking can be challenging
• A child might assume that if they know something, everyone else does too, which can lead to misunderstandings or frustration in group settings
• As their theory of mind develops, these social skills gradually improve

Limitations in Conservation Tasks

• Children in the preoperational stage struggle with conservation tasks because of cognitive limitations like centration and irreversibility
• Centration means they focus on one aspect of a situation, for example, the height of a glass, and ignore others like width
• They also haven’t yet developed the ability to mentally reverse actions, so they can’t understand that pouring water into a new container doesn’t change its quantity
• These limitations make it difficult to grasp that physical properties remain constant despite changes in appearance