Developmental psychology

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Developmental psychology

• Developmental psychology studies how individuals
  change over time and the processes that create
  those changes
• across the entire lifespan.
• The two main processes that cause individuals to
  change across their lifetimes are
• maturation
• Maturation refers to developmental changes that
  occur as a result of the aging process, not from
  injury, illness or other life experience,
  including learning. Maturation information is
  encoded in an individual's genes.
• Learning
• On the other hand, learning is a relatively
  permanent change in behaviour (or potential
  behaviour) as a result of experience or practice.

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METHODOLOGY

• To examine people at different ages,
  developmental psychologists do either
  cross-sectional or longitudinal studies.
• Cross-sectional studies involve looking at
  different people at different ages.
• So, you could examine different individuals at 4
  years of age, 6 years, and 8 years.
• Longitudinal studies involve looking at the same
  people at different ages.
• So, you could look at the same individuals when
  they are 4 years old, when they are 6 years old,
  and when they are 8 years old.
• One problem with cross-sectional studies is that
  it can be unclear whether the results are a
  matter of age differences or of differences in
  the experiences that group of people have
  experienced.

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MAJOR ISSUES IN DEVELOPMENTAL PSYCHOLOGY

• Nature-Nurture
• How much of an individual's development is due to
  nature and how much to nurture?
• Typically, developmental psychologists are
  interested in looking at how these factors
  interact, rather than trying to decide which is
  more important.
• Continuity-Discontinuity
• Whether human development occurs gradually, or
  occurs in a series of breakthroughs.
• People who believe that development is a series
  of stages that people have to work through would
  be in the discontinuity camp.
• Universality-Particularity
• Does everyone go through the same developmental
  processes/stages/aspects or does development vary
  across people, and cultures?
• Although people seem to develop abilities at
  approximately the same age this view has been
  called too simplistic.
• Cultural differences, as well as family
  differences, may influence development.
  Development may be much more multifaceted.
• Critical Periods
• The idea of Critical Periods is linked to these
  major issues.
• A critical period is an age during which the
  individual has to develop a skill, or that skill
  will never be developed.
• Konrad Lorenz did several studies on imprinting
  in birds, which is the name of the process where
  birds learn that the first thing they see when
  they open their eyes is their mother that is,
  they imprint on the first thing they see, and
  take that to be their mother.

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• From the age of 20 months, when her family moved
  into her grandmothers house, until she was 13
  and a half, Genie lived in nearly total
  isolation. Genie was naked and restrained by a
  harness that her father had fashioned, she was
  left to sit on her potty seat day after day. She
  could move only her hands and feet. She had
  nothing to do. At night, when she was not
  forgotten, she was put into a sort of
  straitjacket and caged in a crib that had
  wire-mesh sides and an overhead cover. She was
  often hungry.
• If she made any noise, her father beat her. He
  never spoke to her. He made barking sounds and
  he growled at her. Her mother was terrified of
  himand besides, she was too blind to take much
  care of Genie. The task fell largely on Genies
  brother, who, following his fathers
  instructions, did not speak to Genie either. He
  fed her hurriedly and in silence, mostly milk and
  baby foods. There was little for Genie to listen
  to. Her mother and brother spoke in low voices
  for fear of her father.
• When Genie arrived in Childrens Hospital in
  November 1970, she was a pitiful, malformed,
  incontinent, unsocialized, and severely
  malnourished creature. Although she was beginning
  to show signs of pubescence, she weighed only 59
  pounds. She could not straighten her arms or
  legs. She did not know how to chew. She salivated
  a great deal and spent much of her time spitting.
  And she was eerily silent.
• Various physicians, psychologists, and therapists
  were brought in to examine her during those first
  months. Shortly after Genie was admitted as a
  patient, she was given the Vineland Social
  Maturity Scale and the Preschool Attainment
  Record, on which she scored as low as normal
  one-year-olds. At first, she seemed to recognize
  only her own name and the word sorry. After a
  while, she began to say two phrases that she used
  as if they were single words, in a ritualized
  way stopit and nomore.

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• While Genie did not speak in a fully developed,
  normal way, she acquired some language after she
  was discovered. That contradicted one aspect of
  the theory that says language can be learned only
  during a critical period between two years of age
  and puberty. According to Eric Lenneberg, a
  Harvard psychologist who put forth the theory in
  1967, the brain of a child before the age of two
  is not sufficiently mature for the acquisition of
  language, while after puberty, when the brains
  organization is complete, it has lost its
  flexibility and can no longer acquire a first
  language. Genie proved him wrong in one sense.
  Fromkin says, since the child showed that a
  certain amount of language can be learned after
  the critical period.
• On the other hand, Genie failed to learn the kind
  of grammatical principles that, according to Noam
  Chomsky, distinguish the language of human beings
  from that of animals. For example, she could not
  grasp the difference between various pronouns, or
  between active and passive verbs. In that sense,
  she appeared to suffer from having passed the
  critical period.
• Her language deficiencies could not be attributed
  to a lack of teachers. Though at first it did not
  seem possible that she could ever attend any
  school, within a few months of her arrival at
  Childrens Hospital she began going to nursery
  classes for normal children. She soon transferred
  to a special elementary school for handicapped
  children. Next, she spent several years in a city
  high school for the mentally retarded.
• Nor did Genies deficiencies appear to be inborn.
  Although many details of her early history are
  unclear, and Genies mother has given
  contradictory accounts of them. Genie seems to
  have been a normal baby. She suffered from an Rh
  blood incompatibility, but received an exchange
  transfusion one day after birth. During her first
  year of life, before she was isolated from the
  rest of her family, she may have been on the road
  to language, since her mother reported that she
  heard Genie saying words right after she was
  locked up.
• Genies obvious nonverbal intelligence her use
  of tools, her drawings, her knowledge of
  causality, her mental maps of spacedid not lead
  her to an equivalent competence in the grammar
  normal children acquire by the age of five.

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• Do people have critical periods?
• Not exactly, but sort of. People seem to have
  sensitive periods for developing language, at
  least.
• Genie was kept in confinement by her father from
  the age of 1 to age 13. During that time, she had
  been physically abused by her father, and was not
  allowed to develop normally, nor did she have any
  language skills.
• After being discovered, she was able to make
  great gains in learning, and did acquire some
  language skills. However, she didn't learn the
  full range of language skill that a normal person
  does. Genie learned language up to the level
  (approximately) of a 3 or 4 year old, but no
  further.
• The experiences of Genie suggest that the ability
  to learn language has some limits, although the
  limits are not as cut and dried as the
  prototypical imprinting situation. They were able
  to learn some language, but not anywhere near
  their contemporaries.
• Of course, there are problems with making
  conclusions based on these cases, because they
  did not only have a lack of language in their
  lives. They lacked social interaction with other
  people. They may have been malnourished. And
  certainly for Genie there was a lack of physical
  stimulation as well. Those factors could also
  have hampered these individuals ability to learn
  language. reminder it's always hard to tell
  what's really going on from a single (or even
  only 2) instances or data points
• Other evidence about a critical period for
  language learning comes from research on second
  language learning.
• People who learn a second language later in life
  do not seem to be able to learn it as well as a
  native speaker.
• The time for developing a second language ability
  that is as good as a native speaker is up to
  about 12 or 13 years old.
• However, let me emphasize here that although you
  cannot speak it as well as a native speaker, you
  can become literate in another language, and
  learn to speak it quite well. You simply won't be
  able to speak it as well as your native toungue,
  or as well as someone who's native toungue it is.