Understanding Psychology (10th Ed)

REFLEXES 
A neonate is born with a number of
 refl exes 
—unlearned, 
involuntary responses that occur automatically in the presence 
of certain stimuli. Critical for survival, many of those refl exes 
unfold naturally as part of an infant’s ongoing maturation. 
The rooting refl ex, for instance, causes neonates to turn their 
heads toward things that touch their cheeks—such as the 
mother’s nipple or a bottle. Similarly, a sucking refl ex prompts 
infants to suck at things that touch their lips. Among other 
refl exes are a gag refl ex (to clear the throat), the startle refl ex 
(a series of movements in which an infant fl ings out the arms, 
fans the fi ngers, and arches the back in response to a sudden 
neonate
A newborn child.
refl exes
Unlearned, involuntary 
responses that occur automatically in 
the presence of certain stimuli.
Key Concepts 
What are the major compe-
tencies of newborns? 
What are the milestones of 
physical and social develop-
ment during childhood? 
How does cognitive develop-
ment proceed during 
childhood?
M O D U L E 3 7
Infancy and Childhood
Many of the refl exes that a neonate is born with are critical for survival 
and unfold naturally as a part of an infant’s ongoing maturation. Do 
you think humans have more or fewer refl exes than other animals?
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394 Chapter 
12 
Development
noise), and the Babinski refl ex (a baby’s toes fan out when the outer edge of the sole 
of the foot is stroked).
Infants lose these primitive refl exes after the fi rst few months of life and replace 
them with more complex and organized behaviors. Although at birth a neonate is 
capable of only jerky, limited voluntary movements, the ability to move indepen-
dently grows enormously during the fi rst year of life. The typical baby rolls over by 
the age of about 3 months, sits without support at about 6 months, stands alone at 
about 11 months, and walks at just over a year old. Not only does the ability to make 
large-scale movements improve during this time, but fi ne-muscle movements also 
become increasingly sophisticated (see Figure 1).