Lifespan Development: Infancy, Toddlerhood, and Early Childhood

Comprehensive flashcards covering physical, cognitive, neurological, language, and psychosocial development across infancy, toddlerhood, and early childhood.

In developmental measurements, what is the definition of a percentile?

A number indicating the percentage of people with a smaller number (ranking lower).

In developmental measurements, what is the definition of a norm?

The $50\text{th}$ percentile, where half of the population ranks lower and half ranks higher.

Based on this normal distribution graph of newborn weights, what is the mean birth weight of a newborn baby?

$$7.75\,\text{pounds}$$

By approximately what age does a child typically reach half of their adult height?

Age $2$.

Approximately how many neurons are present in the human brain at birth?

$86\text{ to }100\text{ billion}$ neurons ($86\text{–}100\text{B}$).

What is the core principle of Hebb's Rule in brain development?

"The cells that fire together, wire together."

How many synapses does an infant typically develop by age 2 as a result of dendrite growth?

Approximately $100\text{ trillion}$ ($100\text{T}$) synapses.

What is "transient exuberance" in infant brain development?

The rapid and temporary proliferation of dendrite connections and synapses during the first two years of life.

What is synaptic pruning?

The process by which unused neural connections and synapses wither and die off.

By age 2, the human brain has reached what percentage of its adult weight?

$75\%$ of adult brain weight.

Which brain structure is responsible for regulation and planning, remains essentially inactive for the first 3 months of life, and is the last to mature?

The prefrontal cortex.

At what age does the prefrontal cortex become fully developed?

Age $25$.

According to the 2017 CDC/NCHS data shown below, what are the three categorized causes of Sudden Unexpected Infant Death (SUID) and their proportions?

Sudden infant death syndrome (SIDS) at $38\%$, unknown cause at $36\%$, and accidental suffocation and strangulation in bed at $26\%$.

What is the difference between cephalocaudal and proximodistal trends in motor development?

Cephalocaudal development proceeds from head to toe (head/neck control before legs), whereas proximodistal development proceeds from the center of the body outward to the extremities.

What distinguishes the palmar grasp from the pincer grasp, and at what age does the pincer grasp typically appear?

The palmar grasp uses the entire hand/palm to clutch an object, whereas the pincer grasp uses the thumb and index finger to pick up small objects and emerges around $9\text{ months}$.

What is the Babinski reflex in infants?

When the sole of an infant's foot is stroked from heel to toe, the toes fan out and curl.

What is the Moro reflex?

An involuntary response to a sudden noise or loss of head/neck support in which an infant flings their arms and legs outward and then rapidly pulls them inward.

What is the tonic neck reflex?

When lying on the back with the head turned to one side, the infant extends the arm and leg on that side while flexing the limbs on the opposite side (fencer pose).

Which primary sensory ability is the least mature at birth, and what causes this immaturity?

Vision, because the fetus receives minimal visual stimulation while inside the womb (little experience according to Hebb's rule).

What are Jean Piaget's four stages of cognitive development and their corresponding age spans?

Sensorimotor Period ($0\text{–}2$ years), Preoperational Period ($2\text{–}6$ years), Concrete Operational Period ($6\text{–}11$ years), and Formal Operational Period ($12+$ years).

According to Piaget, what is object permanence and when does it typically emerge?

The understanding that objects continue to exist even when they cannot be seen, heard, or touched, typically emerging around $8\text{ months}$.

What are Piaget's six substages of the sensorimotor stage?

Substage 1: Reflexes ($0\text{–}1\text{ month}$ Substage 2: Primary Circular Reactions ($1\text{–}4\text{ months}$ Substage 3: Secondary Circular Reactions ($4\text{–}8\text{ months}$ Substage 4: Coordination of Secondary Circular Reactions ($8\text{–}12\text{ months}$ Substage 5: Tertiary Circular Reactions ($12\text{–}18\text{ months}$ Substage 6: Beginning of Representational Thought ($18\text{–}24\text{ months}$).

What is the "naming explosion" in infant language development, and when does it begin?

A rapid vocabulary growth rate of learning $3$ or more words per day ($50\text{–}100\text{ words/month}$), typically beginning around $18\text{ months}$.

What is Mean Length of Utterance (MLU), and how is it scored?

A measure of linguistic complexity based on the average number of words or meaningful linguistic units per spoken sentence (e.g., 2 MLU: "Baby cry"; 4 MLU: "Boy is crying"; 6 MLU: "The baby boy is crying").

What did Noam Chomsky propose regarding language development?

That language learning is biologically hardwired and driven by genetics through an innate Language Acquisition Device (LAD).

According to Patricia Kuhl's research, why does an infant's language-learning "genius" slow down before age 1?

Due to Hebb's Rule and synaptic pruning, neural pathways for non-native sounds are lost as the infant's brain specializes in the language spoken in their environment.

What are the three temperament categories defined by Chess & Thomas?

Easy, Difficult, and Slow-to-warm Up.

What are the three temperament categories defined by Zero to Three (Federal Child Care Bureau)?

Adaptable, Feisty, and Cautious.

What is "goodness-of-fit" in child development?

The compatibility between a child's temperament and their social and physical environment, including caregiver parenting practices.

What is synchrony, and what does Edward Tronick's Still Face Experiment demonstrate about it?

Synchrony is a coordinated interactive "dance" between an infant and caregiver; Tronick's experiment shows that when an adult adopts an unresponsive still face, infants experience immediate distress and a steep drop in positive affect.

What did Konrad Lorenz, René Spitz, and Harry Harlow discover regarding early social attachments?

Lorenz identified imprinting in birds (1930s); Spitz documented emotional distress and developmental failure from hospital-induced maternal deprivation (1945); and Harlow showed baby monkeys cling to soft cloth substitute mothers over wire mothers providing milk (1957).

What are the four attachment styles identified using Mary Ainsworth's Strange Situation, and what are their typical proportions?

Secure ($\frac{2}{3}$ of infants), Insecure-avoidant, Insecure-resistant/ambivalent (insecure styles together account for $\frac{1}{3}$), and Disorganized ($5\text{–}10\%$).

Between what percentages does human brain size grow relative to adult size during early childhood?

From $75\%$ to $90\%$ of adult size.

What are the primary lateralized functions of the left and right cerebral hemispheres?

The left hemisphere specializes in language processing, while the right hemisphere specializes in spatial skills.

What is the function of the corpus callosum in motor skills such as crossing monkey bars?

It connects the left and right cerebral hemispheres, facilitating communication and smooth coordination between both sides of the body.

How does prefrontal cortex immaturity relative to the limbic system manifest in early childhood behavior?

Through problems balancing activation and inhibition, presenting as impulsivity (acting without thinking) and perseveration (getting stuck on a single action or thought).

According to NIH motor milestones, what are gross motor milestones expected of a 3-year-old child?

Briefly balancing and hopping on one foot, walking up stairs with alternating feet without holding the handrail, and pedaling a tricycle.

What fine motor milestone is expected of a 4-year-old versus a 5-year-old in drawing shapes?

A 4-year-old can draw a square, whereas a 5-year-old can copy a triangle.

What are the two substages of Piaget's Preoperational stage?

The Symbolic Function substage (ages $2\text{–}4$, mental representation with perceptual dependence) and the Intuitive Thought substage (ages $4\text{–}7$, moving beyond perceptual dependence).

What is centration in Piagetian preoperational thought?

The tendency of young children to focus on only one salient characteristic of an object or situation while ignoring all other aspects (such as focusing solely on liquid height during conservation tasks).

What is animism in early cognitive development?

The belief that inanimate objects (like toys, cars, or clouds) possess lifelike qualities and intentions.

In Vygotsky's sociocultural theory, what is the Zone of Proximal Development (ZPD) as depicted in this diagram?

The space between things a learner can do independently without help and things they cannot do even with assistance.

What is scaffolding in Vygotskian learning theory?

Temporary, tailored support provided by mentors to help a learner accomplish a task within their Zone of Proximal Development until they achieve competence.

What is overimitation in children's learning?

The tendency of young children to copy adult actions that are completely irrelevant and inefficient for achieving the task's practical goal.

What three forms of attention are recognized in the Information Processing model?

Divided attention, selective attention, and sustained attention.

What cognitive capacity is tested using the Sally-Anne false-belief task illustrated below?

Theory of Mind (the child's ability to understand that someone else can hold a false belief that differs from current reality).

What is fast mapping in early childhood language development?

The rapid mental process whereby children connect a new word to a underlying concept after only a single exposure (e.g., words like "tines" or "schnelping").

What is overregularization in children's speech?

The incorrect application of standard grammatical rules to irregular words (such as saying "foots" instead of "feet" or "goed" instead of "went").

How does vocabulary size typically expand during early childhood?

It explodes from approximately $500\text{ words}$ to around $10{,}000\text{ words}$.

What is Erikson's third psychosocial crisis, occurring during early childhood (ages 3–5)?

Initiative vs. Guilt.

What is the difference between self-concept and self-esteem?

Self-concept is how individuals describe themselves (facts and traits), whereas self-esteem is how individuals evaluate their own worth.

Based on this quadrant of caregiving styles, which parenting style is defined by high warmth and high demands?

Authoritative caregiving.

What are Diana Baumrind's four styles of caregiving based on combinations of warmth and demands?

Authoritative (High Warmth, High Demands), Authoritarian (Low Warmth, High Demands), Permissive (High Warmth, Low Demands), and Disengaged/Neglectful (Low Warmth, Low Demands).

What are Mildred Parten's six social categories of play?

Unoccupied play, Solitary play, Onlooker play, Parallel play, Associative play, and Cooperative play.

How much screen time does the American Academy of Pediatrics (AAP) consider excessive for young children, and what are the main risks?

$2+\text{ hours}$ per day; risks include negative impacts on attention, sleep, and behavior.

According to child care quality standards, what is the required adult-to-child ratio and maximum group size for infants (0–11 months) and 3-year-olds?

Infants: ratio of $1:4$ with a maximum group size of $8$; 3-year-olds: ratio of $1:12$ with a maximum group size of $24$.

Approximately how many child fatalities and CPS cases occur per year in the United States due to maltreatment?

About $1{,}600\text{ fatalities/year}$ and over $3\text{ million CPS cases/year}$.

In Utah, approximately how many CPS cases are reported per year, and how many are substantiated?

Around $25{,}000\text{ CPS cases/year}$ reported, with $10{,}000$ substantiated.

How does the most prevalent type of child maltreatment across the United States compare to that in Utah?

Nationally, neglect is the most common form (~$75\text{–}80\%$), whereas in Utah, physical abuse is the most frequently substantiated form (~$40\%$).