Ch4: Infancy - Physical Development

changes in sleep patterns

adult sleep patterns

• about 7-9 hours a night

• generally sleep through the night

newborn sleep patterns

• need more sleep (between 10-21 hours a day; 18 hours on average)

• sleep cycle more erratic (3.5 hours at a time in first few months)

• can start sleeping through night at 3 months/regularly at 6 months

shared sleeping

answer depends on culture

• common practice in some cultures (China and Guatemala)

• in others, newborn more commonly sleeps alone in another room in a crib

• sometimes crib kept in same room as parents for first few months

shared sleep in the US

• controversial

• general trend is against, especially with infants under 6 months

• earlier bedtimes, shorter time to sleep, fewer interruptions when sleeping in separate room

• may be related to risk of SIDS (sudden infant death syndrome)

nutrition

individual differences in infants (as well as adults)

• body composition

• growth rate

• activity levels

changes in eating pattern in first year

• move from suck-and-swallow reflex to chew-and-swallow

• milk/formula > semisolids > more complex foods

• improved motor skills help us move toward self-feeding

• milk/formula is primary source of energy in first 4 to 6 months of life

breast vs. bottle feeding

common question among parents in the US

• debate about which is better for baby still persists

• general consensus is breast feeding is better for baby

• 81% of US mothers at birth

• 52% at 6 months

breast vs. bottle feeding recommendation

• exclusive breast feeding for first 6 months

• continued breast feeding while introducing new foods for year 1

• can continue longer if desired by baby and mother

when not to breast feed:

• mother infected with HIV or some other infectious disease that might be transmitted through her milk

• taking any drug that may not be safe for child

breast vs. bottle feeding benefits

• less likely to become overweight/ obese in childhood and beyond

• less likely to become diabetic in childhood

• lower rates in SIDS

• lower rate of infections

minor qualification:

• most of the above research is based on correlational data

• may not be the one causes the other

• wealthier, higher educated, health-conscious mothers are more likely to breast feed

reflexes

built in automatic reactions to stimuli

• rooting reflex: stroking cheek or side of infant, infant turns its head in that direction in an attemtp to suck

• sucking reflex: automatically suck an object placed in their mouth

• grasping reflex: grasping tightly when something touches infant’s palms

• these lessen after first - 4 months of life, as more voluntary control over body

gross motor skills

involve using larger muscles in the torso, arms, and legs to complete whole-body movements

• sitting up on their own

• standing up (leaning on an object)

• standing on their won

• crawling

• walking

influences on our development of gross motor skills

• developing voluntary control over muscles

• perception of goals in our environment, motivation to develop

• interactions with caregivers that promote development

not all skills may occur, or occur in precise order

fine motor skills

coordination of small muscles in movements, usually involves coordinating movements of the hand, fingers, and eyes to perform tasks

• grasping a toy (“pincer grip” with fingers)

• holding a spoon

• buttoning a shirt

• turning pages

• cutting w/ scissors

attachment

the close emotional bond between people

trust vs mistrust

• parents ability to provide comfort and care for infant helps to establish this basic sense of trust

• This forms basic foundation for lifelong expectations that the world will be a good and pleasant place to be

Bowlby and attachment theory

First year is a sensitive period for the development of attachment between child and parent

• Both parent and child are biologically predisposed to form an attachment

• E.g., Baby’s social behavior (smiling, cooing, following parents around)

• Attachment promotes survival by keeping caregiver nearby

proposes that infants develop an “internal working model of attachment”

• A mental model for understanding the caregiver, their relationship, and their self as deserving to be cared for

• This mental model later goes on to influence relationships with other people (expectations for how we should relate to others)

ainsworth’s strange situation task

Strange Situation is a task developed to assess infant attachment

• Child, parent, and stranger enter room together

• Child left alone with stranger

• How does child respond when parent returns?

Baby’s response classified based on security in attachment

• Securely attached babies

• insecurely attached babies (avoidant / resistant / disorganized)

secure attachment

• seeks out parent for comfort upon return

• Is able to be soothed by caregiver after reunited

• “Check ins” with parent to make sure still there

insecure avoidant attachment

• Avoids caregiver / does not seek out for comfort

• Not as visibly distressed when caregiver leaves the room

• Does not try to re-establish contact when they return

• May avoid eye contact / turn their back on caregiver

insecure resistant attachment

• Cling to caregiver upon reunification, but also resist at the same time

• Kicking, pushing away

• Inability to be comforted

insecure disorganized attachment

• Baby appears dazed, confused, fearful

• Wandering, undirected movements, unorganized patterns of interactions with caregivers

• May show extreme fearfulness around caregive

caregiver secure attachment

• Caregiver is generally responsive and sensitive to needs of child

• “Good enough” parenting (does not have to be perfect)

• Comforting, physical contact, which releases oxytocin hormone (promotes normal attachment between caregiver/infant)

outcomes of secure attachment

• Positive emotional health

• Higher self-esteem

• Higher self-confidence

• Greater social competence in interactions with others (peers, teachers, etc.)

• Less externalizing problems (fights, getting in trouble) than insecurely attached children

criticisms of attachment theory

• is attachment at infancy truly a critical/sensitive period?

• may not adequately consider biological influences or personality factors

• may not adequately address consider cultural contexts

emotions

• positive or negative

• pleasant or unpleasant

• primary emotions and secondary emotions

• temperament

primary emotions

• joy

• sadness

• fear

• disgust

• surprise

• anger

appear in first 6 months of human development

emotions and social interactions

play a large part in our social interactions

• Largely limited to smiling, crying, and laughing, but rapidly expands

• Even these “simple” behaviors can be complex and vary greatly

• Tired cry / angry cry / pain cry

bidirectional relationships and emotions

• Baby’s smile and parental engagement

• Reinforcement and shaping via operant conditioning

• Synchronicity between parent and child

• Adapting our emotional responses based off of the “other”

• Social referencing and reading emotional cues of others

emotion regulation

• Learning emotion regulation is an important developmental milestone

• Gradually develop ability to reduce intensity / duration of emotional reactions

• Even infants have some basic self-regulation abilities (e.g., sucking thumb)

• Largely depend on caregivers for emotion regulation early on

• Various influences on emotional development of infant

• influenced by parents, biology, and environment

influences on emotional regulation

parents and emotion regulation

• Parent’s response to baby’s distress

• Helps to soothe the child before better able to do it themselves

• Over time, baby learns how to regulate through these interactions

• Shaping of their physiological responses

• Debate: Can you be too responsive in first year of life?

biological processes:

• regions of the brain associated w emotional processing

environmental processes:

• how have life experiences shaped emotional development?

temperament

individual differences in behavioral styles, emotions, and characteristics ways of responding

• Even from infancy, children have individual differences in temperament

• E.g., easy-going / aloof / fussy

• Several different methods of classifying temperament

common dimensions to consider:

• Behavioral inhibition

• Effortful control / self-regulation

• Negative affectivity (how easily distressed)

• Extraversion

we learn through the use of schemes (schemas)

• Schemes are mental structures we use for organizing the world around us and interpreting information

• Schemes become more complex as we mature, helping us better understand the world

• E.g., scheme for sucking and grasping as infant (and not much else)

• E.g., scheme for what to do on a job interview as an adult

two concepts to explain how we use and adapt our schemes:

• Assimilation: Occurs when children use our existing schemes to understand new information or experiences

• Accommodation – Adjust their existing schemes to better take into account new information and experiences

• Examples: Moo cow vs. Doggy, Cars vs. Truck

disequilibrium

cognitive conflict when we are confronted with information that contradicts our schemes

• Inconsistency between our understanding of the world and new, conflicting information

• Internal desire for equilibrium creates motivation for change

• We are constantly taking in information, comparing it to our existing schemes, making adjustments, developing new schemes, refining old ones, all to better understand the world around us

• We actively construct our understanding of the world

sensorimotor stage

birth to 2 years

• object permanence: the understanding that objects continue to exist when they cannot be seen, heard, or touched

• Construct their understanding of the world through coordinating sensory experiences with our physical actions

• In beginning, actions guided mostly by reflexes

• Focus on exploring our own bodily sensations / control of body

• Over time, slowly become more goal oriented and using our growing motor skills to explore the environment

attention

the focusing of mental resrouces on select information

sustained attention

the ability to keep your attention focused on something

• improves over infancy

• about 5-10 seconds at a time by age 3 months

determinants of attention

• important stimuli (mom or dad)

• novelty (new stimuli)

• habituation and dishabituation

  • habituation is lessened interest after repeated exposure to a stimulus

  • dishabituation is renewed interested after a change in stimulus

joint attention

when two or more individuals focus on the same object or event

• pointing and looking; paying attention to same TV show

three defining characteristics

1. requires ability to track another person’s behavior

2. one person directs the attention of another

3. reciprocal interaction

aspects of joint attention

• milestone for social behavior

• early on caregiver points or uses words to get attention of infant

• Later (end of first year) infants follow gaze of others

• By 1 year, direct adults’ attention to objects of child’s interest

problems with joint attention and later difficulties

• attachment

• language

• social skills

infantile or childhood amnesia

phenomenon where most adults cannot remember anything from first 3 years of life

• Memories tend to fade away significantly around 9 years of age

brain development and memories

• Long-term memories more fragile in first two years

• As brain development continues, more robust long-term memories

language

form of written, spoken, or signed communication based on a system of symbols

• Many languages share some basic characteristics

• Consists of words used by a community and the rules for varying and combining them

organization of languages:

• Phonology / phonemes

• Morphology / morphemes

• Syntax

• Semantics

• Pragmatics

phonemes

most basic units of sound in a language

morphemes

bare minimum units of meaning in a language

• not just full, complete words

• includes modifiers of words

syntax

involves the way words are combined to form phrases and sentences

semantics

meanings of words and sentences

pragmatics

the appropriate use of language in different contexts

receptive vocabulary

words child can understad

spoken vocabulary

words child can use

recognizing sounds of language (first year)

• Can detect subtle differences between sounds (e.g., “pa” and “ba”) at birth

• Throughout first 6 months, improving at differentiating words / sounds in caregiver’s language

• Gradually lose ability to distinguish for other languages (for sounds not important in own language)

• Recognize some sounds are more likely to occur in some situations than others (e.g., “Mom”)

• Separate stream of speech into words

• Notice patterns that help distinguish between words

• E.g., nt at end of words, br at beginning of words

basic vocalizations (0-6 months)

• Practicing making sounds / attract attention

• Crying (distress)

• Cooing (pleasure)

• Babbling (social interactions)

gestures (7-15 months)

• Pointing / waving goodbye / nodding

• Important milestone for social communication

• Early absence may be indicator of autism spectrum

• Form of joint attention

first words (10-14 months)

• Typically nouns are learned first

• Typically are words most important or familiar to them (e.g., dada, milk, ball)

• Single word used to communicate larger idea (“I want a cookie”)

vocabulary spurt (-18 months)

• Child starts rapidly learning several new words, expanding vocab

• ~50 words by 18 months

• ~200 words by 2 years

two-word utterances (18-24 months)

• Use two words to convey information

• Location / identification / possession…

• “See mama”

• “My candy!”

• “Want milk”

Broca’s area

area of brain associated with production of speech

Wernicke’s area

area of brain involved in language comprehension

Noam Chomsky and the Language Acquisition Device (LAD)

• Argued children are “hard-wired” to readily learn aspects of language via this LAD (e.g., syntax, phonology, morphology)

• Children are biologically prepared to learn language

• Theoretical construct, not a physical part of the brain

• May account for remarkably similar language milestones across cultures / languages

child-directed speech/”parentese”

• Higher-than-normal pitch, slower, exaggerated intonation, simpler words and sentences

• “Mmm! Does that taste good? You want more?”

• Much of this is automatic and not even aware we are doing it

• Captures attention of child, makes it easier for infant to follow and understand

other common adult strategies

• labeling objects

• expanding information

• rephrasing