Child Development – Chapter 5:
Perceptual and Motor Development
Sensory and Perceptual Processes
Smell
● Newborns already have a strong sense of smell.
● They show positive reactions (relaxed face, content expression) to pleasant smells
like honey or chocolate.
● They show negative reactions (grimacing, frowning, turning away) to bad odors like
rotten eggs or ammonia.
Exam tip: Smell is one of the senses that is well-developed at birth.
Taste
● Infants can distinguish salty, sour, bitter, and sweet from the start.
● Most infants show a preference for sweet tastes:
○ Smile, suck harder, lick lips when given sugar or sweet solutions.
● They dislike bitter or sour tastes (grimacing, spitting out).
● Babies are also sensitive to flavor changes in breast milk, which shift with the
mother’s diet.
○ Example: If a mother eats vanilla, babies nurse more afterwards.
Hearing
● Infants hear well, though not as precisely as adults.
● They’re especially tuned to human speech frequencies.
● They also show an early sensitivity to music (can tell rhythm and melody changes).
, Exam tip: Remember that babies are biologically prepared to hear the range of the human
voice → helps them learn language.
Vision
● At birth, vision is the least developed sense.
● Electromagnetic spectrum: By 3 months, infants’ cone cells work properly → they
see full color range like adults.
● Visual acuity: The smallest detail they can reliably see.
○ Newborns see at 6m what adults see at 60–120m (very blurry).
○ Vision sharpens rapidly in the first year.
○ By 3–4 months, color vision is adult-like.
Integrating Sensory Information
● Infants can combine input from different senses:
○ Recognize an object visually that they’ve only touched before.
○ Detect connections between sounds and sights (like lip movements and
speech).
○ Match body movement to musical rhythm.
Example: If you give a baby a toy to feel, later they can recognize it by sight without touching
it again.
Perceiving Objects
● Infants use motion, color, texture, and aligned edges to figure out object
boundaries.
● They develop shape constancy → recognizing an object as the same even when it
looks different from new angles.
Example: A ball rolling away looks smaller, but babies learn it’s still the same ball.
Face Perception
Perceptual and Motor Development
Sensory and Perceptual Processes
Smell
● Newborns already have a strong sense of smell.
● They show positive reactions (relaxed face, content expression) to pleasant smells
like honey or chocolate.
● They show negative reactions (grimacing, frowning, turning away) to bad odors like
rotten eggs or ammonia.
Exam tip: Smell is one of the senses that is well-developed at birth.
Taste
● Infants can distinguish salty, sour, bitter, and sweet from the start.
● Most infants show a preference for sweet tastes:
○ Smile, suck harder, lick lips when given sugar or sweet solutions.
● They dislike bitter or sour tastes (grimacing, spitting out).
● Babies are also sensitive to flavor changes in breast milk, which shift with the
mother’s diet.
○ Example: If a mother eats vanilla, babies nurse more afterwards.
Hearing
● Infants hear well, though not as precisely as adults.
● They’re especially tuned to human speech frequencies.
● They also show an early sensitivity to music (can tell rhythm and melody changes).
, Exam tip: Remember that babies are biologically prepared to hear the range of the human
voice → helps them learn language.
Vision
● At birth, vision is the least developed sense.
● Electromagnetic spectrum: By 3 months, infants’ cone cells work properly → they
see full color range like adults.
● Visual acuity: The smallest detail they can reliably see.
○ Newborns see at 6m what adults see at 60–120m (very blurry).
○ Vision sharpens rapidly in the first year.
○ By 3–4 months, color vision is adult-like.
Integrating Sensory Information
● Infants can combine input from different senses:
○ Recognize an object visually that they’ve only touched before.
○ Detect connections between sounds and sights (like lip movements and
speech).
○ Match body movement to musical rhythm.
Example: If you give a baby a toy to feel, later they can recognize it by sight without touching
it again.
Perceiving Objects
● Infants use motion, color, texture, and aligned edges to figure out object
boundaries.
● They develop shape constancy → recognizing an object as the same even when it
looks different from new angles.
Example: A ball rolling away looks smaller, but babies learn it’s still the same ball.
Face Perception
