Infant, Children, Adolescence in the Premodern and Modern world
Infants become capable of walking and uttering their first meaningful words at about
the age of 1
Individuals reach sexual maturity between ages of 11 and 15, and then age and die
on roughly similar schedules.
Most developmental changes are the product of BOTH maturation and learning
Normative development: Developmental changes that characterize most or all
members of a species; typical patterns of development
Ideographic development: Individual variations in the rate, extent or, direction of
The first 12 years are an extremely important part of the life span that sets the stage
for adolescence and adulthood.
Human development is a continual and cumulative process as we continue to change
with our final change being when we die.
At a time, developmentalists were divided into three groups: (1) those who studied
physical growth and development, including bodily changes and the sequencing of
motor skills, (2) those who studied cognitive aspects of development, including
perception, language, learning, and thinking and (3) those who concentrated on
psychosocial aspects of development, including emotions, personality, and the
growth of interpersonal relationships.
Now, this classification is known as misleading, for researchers who work in any of
these areas have found that changes in one aspect of development have important
implications for other aspects – Holistic Perspective
Prenatal Period – Conception to Birth
Infancy – First year of Life
Toddler Period – 18 months to 3 years
Preschool Period – 3 years to 5 years
Middle Childhood – 5 years to 12 or so years of age (until the onset of
Adolescence – 12 or so to 20 years of age (many developmentalists
define the end of adolescence as the point at which the
individual begins to work and is reasonably independent
of parental sanctions)
Young Adult – 20 to 40 years of age
Middle age – 40 to 65 years of age
Old age – 65 years or older
Plasticity: capacity for a change in response to positive or negative life experiences –
a developmental state that has the potential to be shaped by experience Since human development is so plastic, children who have horrible starts can often
be helped to overcome their deficiencies.
Development is also influences by societal changes: historic events such as wars,
technological breakthroughs, and social causes such as gay and lesbian movements.
Each generation develops in its own way and each generation changes the world for
succeeding generations. Therefore we cannot assume that developmental patterns
observed in North American or European children (the most heavily studied
population) are optimal, or even that they characterize people developing in eras or
cultural settings (culture has a huge influence on individuals).
It is important to look at the historical and cultural context of humans to appreciate
the diversity of human development
Contemporary Western Societies can be described as “child-centered”: Parents focus
much of their lives on their children.
Childhood and adolescence were not always regarded as the very special and
sensitive periods that we regard them as today.
In early days of recorded history, children had few if any rights, and their elders did
not always value their lives. Carthaginians often killed children as religious sacrifices
and embedded them in the walls of buildings to “strengthen” these structures.
Until the fourth century A.D., Roman parents were legally entitled to kill their
deformed, illegitimate, or otherwise unwanted infants.
Even wanted children were treated with cruelty… for ex. Spartan boys.
Not all early societies treated their children with such harshness however, for
several centuries A.D., children were viewed as possessions.
The medieval era was a bit better for children but they were still not coddled and
indulged to the extent that today’s children are.
During the 17 and 18 centuries, attitudes toward children changed. Religious
leaders preached that children were innocent and helpless souls that should be
guarded from the reckless behavior of adults. This is when children started to be
sent to school.. Primary reason for school was to provide proper moral and religious
education but secondary things suck as reading and writing would transfer the
innocents into “servants and workers” who would provide society “with a good labor
Children were still considered family possessions however people were urged to
treat them with warmth and affection.
Adolescence as a separate entity came to be in the 20 century, most likely due to
the spread of industry in Western societies. (Laws in 19 century to restrict child
labor and make school compulsory)
Due to schooling, teens were spending most of their time with age-mates rather than
adults. Due to this, teenagers developed peer cultures and adolescence was
The reason for the drastic change of people’s attitudes towards children can be that
people’s philosophies of children were changing… there was a new look at trying to
understand questions such as whether children are inherently good or bad etc
Thomas Hobbes – his doctrine of original sin held that children are inherently selfish
egoists who must be restrained by society Jean Jacques – his doctrine of innate purity maintained that children are born with
an intuitive sense of right and wrong that society often corrupts.
John Locke – believed that the mind of an infant is a tabula rasa, or a “blank slate”
and that children have no inborn tendencies. Therefore, children are neither
inherently good, nor bad.
Hobbes and Locke believed that children’s roles are passive as they are to be trained
by society to learn to do good.
Rosseau believed that children are actively involved in shaping their own intellects
Since these philosophers had no empirical data to back up their theories, systematic
studies began around the 19 century in the form of baby biographies – a detailed
record of an infant’s growth and development over a period of time.
Charles Darwin is the most influential of baby biographers… he made daily records
of the early developments of his son. His interest in child development stemmed
from his earlier interest in evolution.
Due to baby biographers all focusing in different aspects of child development,
parents being objective and possibly, the biographers letting their own assumptions
influence their findings, many biographies were based on single children but a single
child cannot be representative of other children.
Even though there were many shortcomings, baby biographers were on the right
G. Stanley Hall conducted the first large-scale scientific investigation of children and
because of this, he is considered by most, to be the father of developmental
psychology. He developed questionnaires and set out to ask children questions as he
was interested in their thinking. He found that children’s understanding of the world
grows rapidly during childhood and that the “logic” of young children is not very
He later also wrote a book called Adolescence (1904) that was the first work to call
attention to adolescence as a unique phase of the human life span.
At the same time as Hall, a neurologist named Sigmund Freud was using another
fruitful way of retrieving information on the minds of children: Psychoanalytic
A theory is a set of concepts and propositions that describe and explain some aspect
of experience. Theories help us to describe and explain various patterns of behavior
(in psychology). GOOD theories have the ability to predict future events.
The Scientific method - the use of objective and replicable methods to gather data
for the purpose of testing a theory or hypothesis. It dictates that, above all, investigators must be objective and must allow their data to decide the merits of
Scientifically useful measures must always display RELIABILITY – the extent to
which a measuring instrument yields consistent results, both over time and across
observers, and VALIDITY – the extent to which a measuring instrument accurately
reflects what the researchers intended to measure
Self-Report Methodologies – three common procedures developmentalists use to
gather information and test hypothesis are interview, questionnaires (including
psychological tests) and the clinical method.
Interviews and questionnaires – ask the child or child’s parent a series of questions
pertaining to such aspects of development as the child’s conduct, feelings, beliefs or
characteristics methods of thinking
A questionnaire simply means to put questions on a paper and get the answers in
writing whereas an interview is verbal.
Structured interview or structured questionnaire – a technique in which all
participants are asked the same question in precisely the same order so that the
responses of different participants can be compared
The shortcomings of interviews and questionnaires are that neither approach can be
used with very young children who cannot read or comprehend speech very well.
Investigators also have to assume and hope that the answers they receive are honest
and accurate. (Many adolescent may not want to admit that they masturbate
regularly, smoke marijuana or enjoy the risk of shoplifting)
Ensuring confidentiality is a good way to get more accurate and honest answers.
The Clinical Method – very similar to the interview technique… it sis a flexible
approach that considers each participant to be unique.
Jean Piaget relied extensively on the clinical method to study children’s moral
reasoning and intellectual development
Like structural interviews, clinical methods are often useful for gathering large
amounts of information in relatively brief periods. The strategies flexibility (asking
follow up questions after asking a base question to gather more insight onto the
individual’s answer) is also an advantage due to the exact reason that it provides a
more rich understanding of the answers.
Flexibility is also a shortcoming… It may be very difficult, if not impossible, to
directly compare the answers of participants who are asked different questions.
Furthermore, tailoring one’s questions to the participants responses raises the
possibility that the examiner’s pre existing theoretical biases may affect the
particular follow up questions.
Since conclusions drawn from the clinical method depend, in part, on the
investigator’s subjective interpretation, it is always a good idea to verify these
insights using other research teachniques.
Observational Methodologies – observing peoples behaviour rather than asking
Naturalistic Observation – observing people in their everyday (natural), common
surroundings. To observe children this usually means going into homes, schools or
public parks and playgrounds and carefully recording what they do. (Test specific things such as cooperation or aggression and focus their attention and data
collection exclusively on these acts).
A strength is that it is very easy to apply this to infants and toddlers, on whom
questionnaires and interviews don’t work.
Greatest advantage is though, that it illustrates people literally, in their everyday life
Disadvantage is that some behaviors happen very infrequently (heroic rescues etc)
or so are socially undesirable (ex. Sex play or thievery) that they are unlikely to be
witnessed by an unknown observer in the natural environment.
Secondly, many events are taking place at the same time and any (or some
combination) of them may affect people’s behavior.
Finally, the mere presence of an observer sometimes makes people behave
differently than they otherwise would… children may want to “show off” when they
have an audience whereas parents want to be on their best behavior.
Researchers try to minimize observer influence by (1) videotaping their participants
from a concealed location (2) spending time in the setting before collecting their real
data so that the individuals being observed will get accustomed to the observer
Mary Haskett and Janet Kistner conducted an excellent piece of naturalistic
observation comparing the social behaviors of abused (aggression and negative
verbalization) and non-abused preschoolers (appropriate social initiations and
Monitored 14 abused and 14 non-abused preschoolers as they mingled in a play area
Observations made according to a time-sampling procedure: each child was
observed during three 10 minute play sessions on three different days. (to minimize
observer influence, observer stood outside play area while making their
Results showed that abused children initiated fewer social interactions and were
somewhat socially withdrawn… when they did interact, the abused youngsters
displayed more aggressive acts and other negative behaviors. Non-abused children
often blatantly ignored the positive social initiations of an abused child, as if they did
not want to get involved with him or her.
In conclusion, study shows that abused children are playmates who are likely to be
disliked and even rejected by peers however, as is almost always the case in
naturalistic observational research, it is difficult to pinpoint the exact cause of these
Did the negative behaviors of abused children cause their peers to reject them or did
peer rejection cause the abused to display negative behaviors?
Observational researchers study unusual or undesirable behaviors that they are
unlikely to observe in the natural environment by using structured observations in
In structured observational study, each participant is exposed to a setting that might
cue the behavior in question and is then surreptitiously observed (via hidden
camera or through a one-way mirror).
A shortcoming is that a participant may not react to the situation as they would have
in real life even though the setting tries to encourage natural behavior Case Studies – any or all of the methods talked about up until now can be used to
compile a detailed portrait of a single individual’s development through the case
In preparing an individualized record, or case, the investigator typically seeks many
kinds of information including his or her family background, socioeconomic status,
health status etc.
Baby biographies are examples of case studies
Can also be used to describe groups… study by Michael Bamburg (2004)
investigating identity development in 10, 12, and 15 year old boys. Info collected
from many sources such as journal entries, oral accounts, open ended one on one
interviews and group discussions and from this, Bamburg chose an excerpt from a
single segment of the conversation to illustrate how adolescent males construct their
identities within moment to moment course of a conversation.
The group’s engagement in “slut-bashing” allows the boys to construe their
identities as a morally superior and more adult than the girl’s, while also illustrating
how the boys subtly endorse a stereotypic double standard for girls in comparison to
A lot more is revealed about the boys themselves than they would like the adult to
see from the case study.
Many drawbacks to the approach: often difficult to directly compare subjects who
have been asked different questions, taken different tests and been observed under
Also lack generalizability… some of the conclusions drawn may not be applicable to
the general public
The Bamburg study took place in a large city in the eastern United States so those
results may not be the same for boys in Canada or Finland etc.
Ethnography – form of participant observation often used in the field of
anthropology – becoming popular among researchers who hope to understand the
effects in culture on developing children and adolescents.
Ethnographers often live within the cultural community they want to study for
months or years to collect data.
They collect data through diverse and extensive forms… naturalistic observations,
notes from conversations, interpretations of events etc.
All info is usually compiled to create a detailed portrait of the cultural community
and draws conclusions about the community’s values and traditions and how the
influence aspects of the development of children and adolescents.
Ethnography is highly subjective because researcher’s cultural values and
theoretical biases can cause them to misinterpret their experience.
Results are strictly for the culture or subculture studied… cannot be generalized to
social groups etc.
Posada et al. (2004) used ethnographic methods to assess mother infant interactions
in middle to lower class families in Bogota Colombia and then compared the results
from observations made in Colombian households to results derived using
previously developed assessments Mothers told to carry on daily routine.. observers interacted with family… observers
transcribed their observations
The observer’s transcripts identified 10 domains of maternal care giving. Using
inductive approach, transcripts were reviewed repeatedly and results were
Colombian scales were highly consistent with Caucasian, middle class, and upper
middle class families, showing that sensitive care giving behaviors are similar across
cultures and socioeconomic circumstances, at least within the first five years of an
Psychophysiological Methods – techniques that measure the relationship between
physiological responses and behavior – to explore the biological underpinnings or
children’s perceptual, cognitive, and emotional responses.
Useful for interpreting the mental and emotional experiences of infants and toddlers
who are unable to report such events.
Heart rate (involuntary physiological response) is very useful for assessing
psychological state… EEG (electroencephalogram) recordings of brain activity can be
obtained by attaching electrodes to the scalp… investigators track patterns
determining drowsy, excited, alertness states and can see how these cycles change
with age etc
Novel stimuli also produce short-term changes in EEG activity. Infant sensory
capabilities can be tested by presenting novel stimuli to infant and looking for
changes in brain waves (called event-related potentials or ERPs) to determine
whether the stimuli have been detected.
Brain in action can be observed through MRIs or fMRIs… seeing which parts of the
brain are activated when (or after seeing what).
Can be hard to determine exactly which aspect of the stimulus the infant is reacting
to… colour, shape etc.
Sometimes the mood is reflected rather than a change in he infant’s attention to a
stimulus or emotional reactions to it. (Participant must be initially calm, alert and
MRIs and fMRIs have extremely expensive machinery to be able to generate the
images and so dew machines are available… and the machines that are available are
often required for medical situations rather than research purposes. When the
machines are made available, there may be very strict time constraints which may
not be ideal for the infant’s or child’s participation.
Secondly, technology is invasive and has associated risks, which raise ethical issues,
especially for the young children.
DETECTING RELATIONSHIPS: CORRELATIONAL, EXPERIMENTAL, AND CROSS-CULTURAL
Correlational Design – design that indicates the strength of associations among
variables; though correlated variables are systematically related, these relationships
are not necessarily casual
Investigator gathers information to determine whether two or more variables of
interest are meaningfully related. If researcher is testing a specific hypothesis (rather than conducting preliminary descriptive or exploratory research), he or she
will be checking to see whether these variables are related as the hypothesis
specifies they should be. Participant’s environment is not manipulated in any way…
instead correlational researchers take people as they find them – already
manipulated by natural life experiences – and try to determine whether variations in
people’s life experiences are associated with differences in their behaviors or
patterns of development
Presence or absence of a relationship between variables can be determined by
examining the data to a statistical procedure that yields a correlation coefficient – (r)
This statistic provides a numerical estimate of the strength and direction of the
relationship between two variables ranging from +1.00 to -1.00… the number itself
(disregard the sign) tells us the strength of the relationship. If the sign is positive,
this means that as one variable increases, the other variable also increases ( as
children grow, they tend to get heavier). (the opposite would be as children engage
in more aggressive behaviour, the less popular they are… negative correlation).
These studies do not tell us whether something is caused by the other… it simply
shows a relationship amongst the two variables.
In order to overcome this shortcoming of the studies not being able to tell which
variable causes which, researchers conduct experiments.
Experimental Design – these designs permit a precise assessment of the cause and
effect relationship that may exist between two variables. Laboratory experiments
are conducted to test hypothesis.
There is an independent variable in the experiment… the aspect of the environment
that an experimenter modifies or manipulates in order to measure its impact on the
Dependant variable – the aspect of the behavior that is measured in an experiment
and assumed to be under the control of the independent variable
Confounding variable – some factor other than the independent variable that, if not
controlled buy the experimenter, could explain any differences across treatment
conditions in participant’s performance on the dependent variable
Experimental Control – steps taken by an experimenter to ensure that all the
extraneous factors that could influence the dependent variable are roughly
equivalent in each experimental condition; these precautions must be taken before
an experimenter can be reasonable certain that observed changes in the dependent
variable were caused by manipulation of the independent variable.
Random Assignment – is a control technique in which participants are assigned to
experimental conditions through an unbiased procedure so that the members of the
groups are not systematically different from one another
Greatest strength of experimental method is its ability to establish unambiguously
that one thing causes the other however, critics of lab experimentation have argued
that the tightly controlled lab environment is often contrived and artificial and that
the children are likely to behave more differently in a natural setting.
Ecological Validity – state of affairs in which the findings of one’s research are an
accurate representation of processes that occur in the natural environment.. this is a
way to counter the criticism of lab experiments. (conduct field experiments) THE FIELD EXPERIMENT – conducting an experiment in a natural setting… This
approach combines the advantages of a naturalistic observation with the more
rigorous control that experimentation allows.
THE NATURAL (OR QUASI-) EXPERIMENT – a study in which the investigator
measures the impact of some naturally occurring event that is assumed to affect
people’s lives. There are certain things that cannot be artificially manipulated due to
ethical reasons (such as determining the affect of starvation of intelligence etc)…
therefore, such situations can be assessed through actually finding a population
suffering from a particular situation of interest. The independent variable in this is
the event that the participants experience while the dependent variable is whatever
the outcome one chooses to study.
It is important to note that the researchers do not control the independent variable,
nor do they randomly assign participants to experimental treatments… instead, they
simply observe and record apparent outcomes. Hence, t is often hard to determine
precisely what factor is responsible for any group differences that are found.
Cross-cultural Designs – a research design in which subjects from different age
groups are studied at the same point in time.
Cross-cultural comparisons- a study that compares behavior and/or development of
people from different cultural or sub cultural backgrounds
Compares different social classes and cultures to make sure there are
generalizations from a study done just on a specific group, onto other groups
Guards against the overgeneralization of research findings and is the only way to
determine whether there are truly “universals” in human development
Investigators who favor the cross-cultural approach are looking for DIFFERENCES
rather than similarities amongst studies done with various different cultural/ethnic
Main point is to show that whatever holds true in our society, is not necessarily the
case in another.
RESEARCH AND STUDYING DEVELOPMENT
Cross-sectional design – people who differ in age are studied at the same point in
time… participants at each age level are different people… That is, they come from
different cohorts – a group of people of the same age who are exposed to similar
cultural environments and historical events as they are growing up.
Can often identify age related changes in whatever aspect of development they
happen to be studying
Can collect data from participants at different ages over a short period of time
Cohort Effects – in cross-sectional research, participants come from different cohorts
and therefore, some of the differences in the age groups may not be simply because
of age, but of different cultural or historical factors (a 60 year old compared to a 19
year old has an age AND a generation gap…)
Data on Individual Development – cross-sectional design tells us nothing bout
development of individuals because each person is observed at only ONE point in
time. Therefore, as there is no follow up study… there is no information on change
and development The Longitudinal Design – the same participants are observed repeatedly over a
period of time… investigators are able to assess the stability (continuity) of various
attributes for each person in sample… they can also see normative and ideographical
developmental trends among individuals
Issues arise however because tracking a group of people for multiple decades is very
difficult… some people pass away or choose not to participate anymore etc.. very
costly and time-consuming. Practice effects also threaten the validity of the study as
participants who are repeatedly interviewed or tested may become familiar with the
content of the test and simply show improvement because of that, rather than any
other reason… this can be misinterpreted.
Selective Attrition is when children move away or become bored with participating,
or may have parents who, for some reason or the other will not allow their child to
participate… The end result is a smaller and potential nonrepresentative sample – a
subgroup that differs in important ways from the larger group or population to
which it belongs
Another issue is cross-generational problems – the fact that long term changes in the
environment may limit the conclusions of a longitudinal project to that generation of
children who were growing up while the study was in progress
The Sequential Design – combines the best features of cross-sectional and
longitudinal designs… selecting participants of different ages and following each of
those cohorts over time… Three major strengths are that it allows us to determine
whether cohort effects are influencing our results by comparing (for ex.) the logical
reasoning of same-aged children who were born in different years… Second major
advantage is that it allows us to make both longitudinal and cross-sectional
comparisons in the same study. Finally, sequential designs are often more efficient
than standard longitudinal designs.
The Microgenetic Design – the other three designs provide only a broad outline of
developmental changes without necessarily specifying why or how these changes
take place. Microgenetic designs are used in an attempt to illuminate the processes
that are thought to promote developmental changes. Logic is simple: children who
are thought to be ready for an important developmental change are exposed
repeatedly to experiences that are though to produce the change and their behavior
is monitored as it is changing.
Cognitive theorists have used this approach to specify hw children come to rely on
new and more efficient strategies for solving problems… by studying participants
intensely over a period of hours, days or weeks, and carefully analyzing their
problem-solving behavior, it is possible to specify their thinking and strategizing is
changing to advance their cognitive competencies, arithmetic skills, memory, and
It is promising for illuminating the kinds of experiences that can promote change sin
such areas of social and personality development as self –concept and self-esteem,
social cognition, reasoning about moral issues, and thinking about gender-role
Disadvantages include that it is time-consuming and costly to track large numbers of
children in such a detailed manner… Since a lower population number is usually used for this design (as it is costly and hard to track too many), practice effects may
come into play as the children are taking many trials in a short period of time
Criticisms of the approach include that the intensive experiences children receive in
order to stimulate development may not reflect what they would normally
encounter in the real world and may produce changes that my not persist over the
Thus, it is typically used to investigate age-related changes in thinking or behavior
that are already known to occur.. purpose is to specify more precisely HOW or WHY
these changes might occur…
It is generally considered permissible to observe young children in natural settings (for
example, at school or in a park) without informing them that they are being studied if the
investigator has previously obtained the informed consent – the right of research
participants to receive an explanation, in language they can understand, of all aspects of
research that may affect their willingness to participate- of the adults responsible for the
children's care and safety in these settings. Ethical guidelines are just that: guidelines. The
ultimate responsibility for treating children fairly and protecting them from harm is the
In order to decide what is ethical or not, the advantages are weighed against the
disadvantages of the research by carefully calculating its possible benefits to humanity or
the participants and comparing them with potential risks. If the benefits-to-risks ratio – a
comparison of the possible benefits of a study for advancing knowledge and optimizing life
conditions versus its costs to participants in terms of inconvenience and possible harm – is
favorable and if there are no other less risky procedures giving the same benefits, the
investigator will generally proceed. In Canada there are “human-subjects review
committees” which provide a second and third opinion on such situations in case there are
Clashes between the ethical provisions of confidentiality – the right of participants