Infant Development: Percentiles, Sleep, Brain, Language, and Temperament

What does the 20th weight percentile mean?

The baby weighs more than 20% of infants their age.

What does the 75th weight percentile mean?

The baby weighs more than 74% of infants their age.

What is bed sharing?

An infant and caregiver sleep in the same bed.

What is co-sleeping?

An infant and caregiver sleep in the same room.

What is a neuron?

A nerve cell that sends and receives information.

What are dendrites?

Parts of neurons that receive signals from other cells.

What is a synapse?

The connection point where neurons communicate.

What are neurotransmitters?

Chemicals that carry messages between neurons.

What is the cortex?

The outer layer of the brain involved in complex thinking.

What does the prefrontal cortex control?

Planning, decision-making, and controlling behavior.

What is transient exuberance?

Rapid growth of many new dendrites in the brain.

What is pruning?

The process where unused dendrites weaken and die.

When do children walk well on average?

Around 1 year old.

What is head sparing?

The brain keeps growing when body growth is slowed by malnutrition.

Why is breastfeeding discussed in infant development?

It is one way infants can receive needed nutrition.

Why are immunizations important?

They help protect infants from serious infectious diseases.

What is gaze following?

Looking toward the same object another person is looking at.

What is core knowledge?

Basic understanding infants have about how the world works.

What is an example of core knowledge?

Knowing a rolling ball will stop when it hits a wall.

What is implicit memory?

Memory that was never consciously put into words.

What is explicit memory?

Memory that can be consciously remembered and put into words.

What are circular reactions?

Repeated actions infants perform to explore their world.

What is a primary circular reaction?

Repeated actions involving the infant's own body.

What is an example of a primary circular reaction?

Thumb sucking or practicing feeding skills.

What is a secondary circular reaction?

Repeated actions involving objects outside the body.

What is an example of a secondary circular reaction?

Repeatedly shaking a rattle.

What is a tertiary circular reaction?

Trying new actions to see what happens.

What is an example of a tertiary circular reaction?

Trying different ways to knock blocks over.

What is object permanence?

Knowing an object still exists when it cannot be seen.

How can caregivers promote language skills?

Talk, read, respond, and interact with infants often.

What is babbling?

Infants making repeated speech-like sounds.

What is a holophrase?

One word used to express an entire thought.

What is an example of a holophrase?

Saying "outside" to mean "I want to go outside."

What is the naming explosion?

A rapid increase in vocabulary after learning about 50 words.

What is mean length of utterance (MLU)?

The average number of words in a child's typical utterance.

What does an MLU of 5.5 mean?

The child's average utterance contains about 5.5 words.

What does the behaviorist theory say about language?

Language develops through teaching, reinforcement, and conditioning.

Who is associated with behaviorist language theory?

B. F. Skinner.

What does the social interaction theory say?

Social interaction and communication help infants develop language.

What does Chomsky's theory say about language?

Humans are biologically prepared to learn language.

What is the Language Acquisition Device (LAD)?

Chomsky's idea that humans are biologically prepared for language.

What does experience-expectant mean?

The brain expects certain common experiences for normal development.

What does experience-dependent mean?

Development shaped by unique individual experiences.

What happens during separation anxiety?

Infants become distressed when a familiar caregiver leaves.

What is stranger awareness?

Infants become wary or fearful around unfamiliar people.

What is temperament?

Biologically based patterns of emotional and behavioral responses.

What are the three temperament domains?

Effortful control, negative mood, and exuberance.

What is effortful control?

The ability to control attention and behavior.

What is negative mood?

A tendency toward unpleasant or negative emotions.

What is exuberance?

A tendency toward high energy and positive engagement.

What is synchrony?

Caregiver and infant respond to each other in coordinated ways.

What is the still-face technique?

A caregiver becomes unresponsive while researchers observe the infant.

What does the still-face technique show?

Infants expect caregivers to respond and interact with them.

What is secure attachment?

The infant explores, becomes upset when caregiver leaves, and seeks comfort.

What is insecure-avoidant attachment?

The infant shows little proximity seeking and avoids the caregiver.

What is insecure-resistant attachment?

The infant is very distressed and may resist comfort after reunion.

What is disorganized attachment?

The infant shows confused or contradictory attachment behaviors.

What is proximity seeking?

Trying to stay physically close to an attachment figure.

What is allocare?

Care provided by someone other than the infant's parents.

What are examples of allocare?

Daycare workers, grandparents, aunts, or other caregivers.

Does daycare automatically weaken infant attachment?

No. Early daycare does not necessarily diminish attachment.

What makes daycare high quality?

Attention, safety, learning support, professional caregivers, and parent involvement.

What does behaviorism say about psychosocial development?

Behavior is shaped by reinforcement, punishment, and observation.

What does cognitive theory focus on?

How infants interpret experiences and form working models.

What is a working model?

Assumptions used to organize perceptions and experiences.

What does evolutionary theory say about attachment?

Emotions and attachment help infants survive and stay near caregivers.

What does psychodynamic theory focus on?

Unconscious processes and early experiences in personality development.

What is Erikson's first infant stage?

Trust vs. mistrust.

What is Erikson's second early-childhood stage?

Autonomy vs. shame and doubt.

Open response: Explain the three circular reactions.

Primary = body; secondary = objects; tertiary = trying new actions.

Open response: Explain the four attachment types.

Secure, avoidant, resistant, and disorganized describe different reunion behaviors.

Open response: Explain the three language theories.

Behaviorism, social interaction, and biological/genetic theories explain language learning.

Open response: Explain temperament and its three domains.

Temperament is biologically based; domains are effortful control, negative mood, and exuberance.

Open response: Explain theories of infant psychosocial development.

Psychodynamic, behaviorist, cognitive, and evolutionary theories explain development differently.