● We have big heads when we’re born. 25% of adult size, 5% of adult size when born.
● As newborns, our big heads can not handle our bodies. We are very helpless as infants.
● We’re able to slowly become physically independent throughout the ages of 2-15 months
Development of visual systems
● Ababy can see up to 20 feet, but see very poorly.After a year, their vision (occipital lobe)
● Rods and cones develop after
● We have no visual stimuli in the womb, so visual development only occurs outside of it
● Depth can be perceived by crawling age
A. Body and movement, how well we coordinate our muscular control and
B. Prone, chest up, use arms for support
● . 2-4 months (for 95% of babies)
● . 4 -5 months – sit without support
● . 5-10 months – Stand with support
● . 6-10 months – Pull self to stand
● . 10-14 months – Stand alone early
● 11-14 months – Walk alone freely
● 250k new neuron/minute in developing fetus
● Lots of brain development towards end of pregnancy. This is also when pregnant women
get sick most easily. Their body is more susceptible to toxins. It is an adaptation so that
the pregnant do not risk introducing to babies hazardous things. Women typically crave
sweets, ice cream, meat.
● New neurons grow rapidly until age 2
● Unused neurons die off, but they are repurposed for other things if that part of the brain
doesn’t get stimulated. This is like “pruning a tree”. Those weak branches are sucking
energy from the tree.
● Prenatal programming - events in womb alter physical/psychological health
● Teratogens - toxins - can cause permanent damage, like fetal alcohol spectrum disorder
Neural growth and synaptic pruning
● Brain is shaped by experience. Early in infancy synaptic connections grow at a
tremendous rate and are indiscriminate, forming with any neural cluster.
● Process of learning “prunes” unused synaptic connections and reinforces/consolidates
used ones. Pruning still occurs in late childhood.
● Childhood/infant neglect creates fewer and less developed neural connections. This
occurs when basic sensory experiences are not given.
● “Use it or lose it”. Neural structure degrades when we don’t use certain neurons in our
brain. It’s why we forget things. Nature makes the brain more efficient this way. If it
doesn’t get used, then the brain will dynamically adapt. ● Hippocampus in neural system is not as complex if environment is not as stimulating.
● Children’s brains more sensitive to simulation, since they have less myelin for a more
● Neural migration - movement of neurons from one part of fetal brain to permanent
destinations during months 3-5 of pregnancy Fetus movements noticeable after 4-6
Brain plasticity and neglect
● Less brain activity in neglected people. Neglect prevents brain growth.
Musical training changes the brain
● Brains of trained musicians are different from brains of non-musicians.
● Only a minority really learn music. Plasticity of trained musicians vs. non-musicians:
Larger corpus callosum (connects hemispheres) (because musicians listen with both ears,
there is a lot more interaction with both hemispheres!), cerebellums(coordination and
timing) in musicians, especially if started by age 7
● Linear effect - earlier you start, the bigger your brain is.
● Cortical regions in rain involved in finger movement grew in piano players.
● When you do the same thing every day, all the neurons you do become so strongly
connected, that those activities become automatic. It’s why muscle memory takes so long
● IQ has nothing to do with it
● We see the world as
● Brain and reasoning need to develop
Developmental stages of a fetus
● Germinal stages - conception of single-celled zygote (fertilized egg), blastocyst by day 7
● Growing bundle of cells 2 weeks after conception = embryo
● Embryonic stage: Major organs marked, growth continuing until 8 weeks after
● Fetal stage - formation of bone cells 8 weeks after conception. Can hear heartbeat
between now and 12 weeks which helps differentiate between positive and negative
reactions. (High = distress, low = attention, interest)
Development in infants
● Rooting and grasping present at birth.
● fine motor skills develop gradually from 2-5, b/c they involve coordination of smaller
● Hearing almost fully developed at birth.
Early cognitive development
● Cognitive skills growing in infants who can not yet speak are noticed through their attention spans on what they look at. When something is examined for more than a few
seconds, brain activity narrows from many brain regions to more specific brain regions.
● sensorimotor stage - first stage of development where infants learn about world through
their senses. Sense more than think.
● No concept of object permanence - objects exist when they are not being sensed - for
● Preoperational stage - 2nd stage where symbolic thinking develops, suchs as words or
letters to represent ideas.
● Aniministic thinkings - idea that inanimate objects are alive
● Egocentrism - tendency to view world from only one’s perspective
● Conservation - ability to recognize that when some properties change, other properties
● Concrete operational stage - children can perform mental operations, but still have
trouble with abstract ideas and reasoning.
● Formal operational stage - logic becomes possible
● .Lev Vygotsky developed more social view of cognitive development - Zone of proximal
development - child learns alone vs. child learns with assistance
● Learning is a social process
Theory of Mind
● Knowledge and ideas of how other people’s minds work.
● false-belief test - children under 4 can’t imagine things from another’s perspective.
● Lawrence Kohbert claimed 6 stages of development based on the work of Jean Piaget
● preconventional level - first and least developed - avoiding punishment or maximizing
reward. (Children obey because they are told to) Further more, there is a self-interest
● Conventional level - personal values (interpersonal accord and conformity, social norms)
and relationships are taken into account along with lawfulness (authority and social order
● Care for others in the conventional level can be seen as a penalty, especially towards
● postconventional level - personal acknowledges both the norm and the law (social
contract orientation), but recognizes that disobeying the local rule may be necessary for
universal moral rules. (principled conscience).
● Postconventional morals are limited to Western cultures, because individual values are
● infants soon settle into predictable routines after birth
● Easy child - predictable in daily function, happy most of the time. 40%
● Difficult child - unpredictable in daily functions and unhappy most of the time. 10%
● Slow-to-warm-up child is mildly intense and mildly irregular in daily patterns. 15%
● 35% not classified by any of these
Early socioemotional development
● imprinting:Animals follow and imitate the first large creature seen.
● attach: strong emotional connection that develops early in life to keep infants close. This shapes the child’s social and emotional development
● separation anxiety - protest, despair, detachment when separated from caregiver.A
distress reaction when separated from primary caregiver
● John Bowlby(1969) developed attachment theory
● Asecure base is created for an infant. Confidence and security can be developed so that
they’ll explore the world.
● Internalization of the bonding relationship - provides mental model on which they build
future friendships and love relationships.Attachment to a caregiver is most critical of all
relationships. Infants are more than a passive receptor, they respond and influence one
● strange situation: experiment where distress of the infant is correlated with the
● secure attachment is when infants are happy and initiate contact when the mother
● insecure attachment has three types where insecure-avoidant, insecure-resistant, and
● insecure-avoidant attachment:Infant shows little to no distress, but stress tests indicate
they are under stress.
Important attachment research
Rene Spitz and the Orphans (1940s)
● Lack of touch and interpersonal contact caused severe stunted physical and psychological
● By age 3, 1/3 died and less than 5% could walk, feed themselves, talk in sentences!
Leads to attachment disorders later in life
Tiffany Fields and Low birth weight infants ( 1970)
● Touch for 15 minutes per day results in faster weight gain and fewer long term deficits
for premature infants. Less diarrhea and reduced stress
Harry Harlow and Rhesus monkeys (1950s)
● wire but milk mother
● Cloth but no milk mother (preferred)
● Had 2 mothers, so he could spend more or less time with either of them. He would stay
with the warm mother, because the baby monkey finds it the secure base.
● These babies grew up messed up - very abusive.Abusive parents who neglected or
● Not socially developed as adults
○ Abusive parents and abnormal sexual behavior. Hyper-aggressive and violent
● Need more than food to survive, we need physical warmth and contact.
Need social and physiological supplements for survival.
● Harlow’s monkey research proved physical contact is central to human development.
● touch therapy used to improve motor skills in children with cerebral palsy, a movement disorder, and autism.
Social relationships and emotional development
● Babies learn to communicate through facial expression via mimicking adult expressions.
(possibly mirror neurons)
● Babies seem to know what facial expressions mean.
● By age 1, babies can make sense of emotional faces.
● Social referencing is usage of social and emotional information
● Other children > big impact on child
○ Social interaction Begins @ age 3
○ Bigger influence than parents
● Peer influence begins @ 5
○ Gender segregation
■ Play preferences
Development of emotions
● Pleasure and pain are first emotions felt by babies
● 2-3 months of age, babies respond with smile.
● 1 month later, they laugh at playful social interaction
● Anger > 4 months. Babies may mistakenly use anger faces when they feel fear
● 4-7 months > anger when restrained of movement.
● emotional competence: Controlling emotions and knowing when to express them.
● By age 9, children realize impact of their reactions on others’feelings.
● 3 types of temperament
■ Impulsive, temper tantrums
● Impulsive, thrill-seeking behaviors, relationship conflict
likelihood, aggressive, hostile, alcohol abuse
● Less social support, avoid risk/harm, nonassertive,
● More likely to attempt suicide, alcoholic issues, as likely as well-
adjusted to commit crimes
● least amount of social, emotional, and financial support from
others as adults
○ Curiosity, imagination, openness biased towards boys for cognitive potential
● Psychoanalytic theorist
● Developed an 8 stage model of psychosocial development
● Each stage has its own “identity crisis” or conflict that can result in positive or negative change.
● Primarily Western study where emphasis on the individual is made
● Puberty: sexual maturation, beginning of adolescence
○ major hormonal changes > prepare body for reproduction
■ body size and proportion changes
○ girls ~11, boys ~13
○ pituitary glands > hormonal signals to sex glands > signal to mature
■ sex glands/gonads release sex hormones
● male gonads = testes
○ release testosterone
■ initiates physical changes we associ