Developmental Chapter 2
In order for a theory to be useful, it must help us predict certain behaviors such
as how a child will develop, and why it develops the way that it does
How do developmental psychologies conduct research? Some methods are
similar to the standard methodology, but they take into consideration time.
The scientific method
Scientific method a hypothesis is formed on the basis of a theory where
measurable, objective, and repeatable techniques are used to collect, study and
At the heart of scientific research, we try and replicate other reports
We observe, and based on these observations we then formulate a theory and a
hypothesis to test that theory. Once you find measures to test your hypothesis,
the results you obtain will either allow you to keep your current theory, and
refine or retest it for accuracy, or you will reject the current theory, and
formulate a new one.
In order for a theory to be a true theory, it must be falsifiable.
Issues to consider in collecting Data
Variable relationships: there is factors that vary and change can result in a causal
relationship. However, not all relationships are causal, some are co relational.
Independent variable: the variable that is being manipulated, it is under
Dependant variable: the variable that is being measured, it is affected by the
Operational definition: defining objects in terms of measurable characteristics.
Ex- what's aggression? The number of times one child hits another. This is
describing it in terms of objective measurable characteristics. A lot of the
phenomena that we deal with in psychology are operational definitions.
It defines the concept in the way we can measure them
Why would an operational definition be problematic?
o There are lots of ways of looking at aggression other than hitting people.
Using this operational definition, someone who is yelling at another
individual is not as aggressive.
o To remedy this, you could include multiple characteristics in the
operational definition. However you still have to think about how the
operational definition will constrain other variables.
Sample: a group of individuals of manageable size used to represent the
Representativeness the extent to which the individuals in a sample possess
the characteristics of the larger population in the sample.
o Might need a large sample to achieve a more accurate level of
representativeness- if the effect you are examining is small or if the
variance of the population is large. o Random assignment is a technique where individuals are randomly
assigned to the experimental or control group. This is done to avoid
systemic differences between subjects in each group
o One solution is using multiple samples, each mad up of various races,
genders, and social classes. By selecting multiple samples it can
ensure that ones result are in fact more accurate, and they can have
greater confidence in their findings
o Another approach: the national survey
National survey: Researchers, who are interested in a particular issue,
select a very large nationally representative group of people.
Advantage: it shows that the pattern discovered is not confined to the
people who shared the characteristics of those studied.
Disadvantage: costly (surveying many people), ]it does not allow them to
answer specific questions. Thus, this form of testing is usually paired with a
subgroup, using such a large sample, the examiner must be sure that it not
only represents age, gender, socioeconomic status, but it must be certain
that it c=recognizes the diversity of their population as unless they are
trying to target a specific ethnic group, they will lose opportunities to
discover important ethnic differences
Generalizability? What kind of generalizations can we make from he results
of our sample?
Reliability is how consistent the results will be if the test was administered
repeatedly. It deals with consistency among time and measure.
o Test-retest method:
Concerned with measurements being consistent over time.
Involves taking measurements of a variable on two separate
o Internal consistency
The measurements of a variable should be consistent over items
designed to measure a variable, the individual should exhibit the
same behavior across a various situations. This involves taking
multiple measurement of a variable (via different items) on a
o Inter-rater reliability
Measurements of a variable should be consistent over observers.
This can be accomplished by taking multiple measurements of a
variable on one occasion by different observers
Validity the degree to which the measures accurately measure the variable
under construction. It makes certain that what we want measured is being
o How do we judge validity? Operationalize the variable; specify the
behaviors that are considered aggressive.
Methods of data collection
Developmental is different as we have two conflicting goals:
o Naturalistic: we want to answer questions about the real world, and
want our experiments to reflect the real world Ecological validity: the degree to which a variable or
experiment accurately reflects the events in the real world
o Control: we want to draw conclusions about cause and effects by
eliminating other effects. We want to draw conclusions. Thus, we have
to eliminate variables that impact the results. The more ecologically
valid the study is, the less control one has.
Thus we want to be naturalistic while simultaneously having control.
Methods of Data Collection
Observation and recording of behaviors in a natural setting Simply observing
and recording the behaviors in a natural setting, no manipulation of variables
thus no control
Ex- daycare observation- kids in their normal environment, it is very
naturalistic in terms of their measures. You get highly ecologically valid
Record behaviors in a situation that is constructed by the experimenter
Ex Ainsworth Strange Situation the experimenter sets up a specific set of
scenarios, and the researcher watches each set of scenarios and compares
them. It is less ecologically valid.
Problems with Observation
Observer bias when a research is knowledgeable about a particular topic, and is
thus influenced in their evaluations by that knowledge
o They tend to interpret ongoing events as consistent with their hypothesis,
the observers beliefs can influence what they see
o How can this be overcome? Double blind technique. – Observers are
hired who are unaware and ask them to mark down specific behaviors
that they are monitoring.
Observer influence: people tend to act differently when they know they are
Methods of Data Collection
Self report the information an individual provides about him or herself,
usually by answering questions asked by the researcher.
Two Basic ways:
o Structured- standardized (i.e. researcher will ask specific questions)
ex- IQ tests
o Clininical method- non structured- in which the questions depends on
the response the child gives. Ex- dr. Phil never asks the same question,
it depends on the previous response that was given. Freud started
this; it was based on a medical type of model.
Questionnaires: standardized questions presented in larger groups. The
benefit to this is that they are fast and can be administered to a large group.
Problems with self-report: Accuracy: individuals being interviewed may be embarrassed to answer
truthfully. You say things to impress the people around you, and answer in
ways that you think will please the interviewer
o Interviews are always retrospective- memory is constructive and
therefore not always accurate. You may have poor memory
recollection of a event that happened
Experimenter bias: especially in the non-structured interview, the researcher
may be biased toward a particular hypothesis and formulate questions with
that bias and interpret the answers in a biased fashion
o You can phrase to the question that will lead the individual being
interviewed to respond in a certain way.
When it comes to children:
Children are less attentive, slower to respond, have difficulties
A study showed that children are just as truthful as adults, however when
parents are present are less truthful
It is beneficial as it provides the researcher with the Childs perspective on
their life, that a teacher or parent might not know
Disadvantage: memory is not always accurate, and they like to be seen in
the best light possible i.e. Study -Robbins compared parent’s
retrospective reports with reports that the same parents made regularly
over the course of a 3-year long study. He found distortions in parent’s
recall of event to agree with then-contemporary experts. Ex parents who
were concerned over thumb sucking denied that their child sucked their
thumb as often due to a book that disproved thumb sucking
When parents see children as extensions of themselves, they don’t report
as honestly (ex- will say child has better grades then they do)
To ensure accuracy of parents reports- might call the parents at the end
of day to report the behaviors of child over the past 24 hours, ask parents
to carry around a diary, or page parents randomly to record events
Recent research has shown that parents were accurately able to report
children’s cognitive functions (reading comp, visual and auditory
Teacher and Peers
In some settings, such as school, parental reports are not beneficial
Researcher will ask peers how much they like to play with the child or ask
teachers how attentive, disruptive, dependable a child it
Methods that examine the sympathetic nervous system (fight or light)
Brainwaves measured at the scalp change with maturation in amplitude and
It doesn’t hurt when it is on. Nothing is going into the brain, just measuring
what is coming out ERP-event related potential ERP
Time-locked ERP which measures stages of processing in the brain-good
It is an eeg that is averaged over several trials, and can eventually get an
averaged brainwave response to see the brain activity of particular response
Both rely on electrical activity emanating from the scalp [. You put a cap on
someone’s head and record the brainwaves that result from it records
millisecond by millisecond, and is not invasive (which is why its so common)
Over time, the bran waves mature, they become cleaner and less noisy.
FMRI- functional Magnetic Resonance imaging
Measures blood flow to different regions of he brain depending on the task-
good spatial resolution MRIs get a nice visual image as opposed to EEG were
you get a wave.
With MRIs you can see where the brain activity is occurring, but it is not
millisecond by millisecond
The middle one. You look at parts of the brain that lights up. You look at the
electromagnetic field around the head. You can get a second by second
change and overlay it on top of the picture of an MRI, i.e. the image on the
right. You get a nice spatial representation.
The MRI itself has been very informative, however, there has not been any
information developmentally. They don’t do research based mris on baby
because it is scary to be in the enclosed spaced. MRI as a technology of
developmental use is less common than the EEG because of the limitations of
MEG: magneto encephalogram
MEG: magneto encephalogram: measure changes in the magnetic field
around different brain regions
Good spatial and temporal resolution
Combination of the EEG and MRI. You can localize where it is coming from
and get a spatial representation of where it is coming from
They are not really used for developing individuals such as children or
infants. There is only one MEG machine in Canada, located at the ROT
Institution in Toronto
Physiological methods problem
Ultimately. These types of studies are correlational. We are assuming that the
[art or area that controls a particular area is probably related, but it does not
mean it translates into an actual response. Thus, it’s a useful tool for
researchers to get started but that’s about it
The clinical method/ The Case Study method
Case study method is the study of individual person over times. It is useful
for the study of the effects of unique deficits
Darwin one of the first case studies- studies his sons emotional development
Ex- HM. He was a guy who had a bilateral lesion of his hippocampus; parts
removed to control his epileptic seizure. Problem-was it left out any