Why do psychologists do experiments? Psychology is very hard to define due to
it's very nature and the wide range of topics that it covers. No two books will
give exactly the same definition of 'psychology' or what subject matter it
covers. However most definitions would suggest psychology to be the 'scientific
study of behaviour and mental processes.' An astonishing variety of topics is
covered under this definition for example topics can range from 'obesity' to
'living with a divided brain', from 'expression of aggression' to 'childhood
amnesia'. No one today can afford not to know psychology as it touches every
aspect of life. For example: How does the way your parents raised you affect the
way you raise your kids? What effect does stress have on your immune system? How
effective is psychotherapy when treating depression? How should instruments in a
nuclear power station be designed to minimise human error? Can men care for
infants as ably as women? Psychologists work on these and many more questions
which need to be answered as through psychological theories and research we can
learn to better understand ourselves, what motivates us and how to handle
situations in a better way although each situation and the individuals involved
in it are unique, some things could be applied to real life. For example parents
may learn that reward is better than punishment when handling their kids. Also
such theories and research have and will continue to influence laws concerning a
number of areas such as capital punishment, pornography, sexual behaviour (for
example sexual deviancy) However as most questions like the ones mentioned above
relate to the 'psyche' (a totality of inner experience lacking in spatial
dimensions) the problem is: How do external observers investigate someone else's
psyche systematically if they cannot understand it with their senses?
Behaviourism, a movement in psychology, maintains 'we cannot study the psyche at
all because its immateriality renders it inaccessible to measurement.' This is
where experimentation comes in. An experiment is a 'method of investigation in
which the researcher manipulates the situation in order to bring about a change
in the research participant's behaviour.' Behaviourists, use cause-effect
methodology to measure the directly observable: the environment and behaviour as
this is essentially the only way one can get an insight in to the answer of any
of the above questions. However many psychologists object to this exclusively
behavioural definition saying that a complete denial of the psyche prevents them
from making inferences about the phenomena behind behaviour. If psychologists
can explain behaviour by referring to consciousness, cognition, thought or
emotion, then they can risk a much richer range of predictions about behaviour.
Thus many psychologists regularly construct theories about the psyche, but still
choose to base them on the experimental observation of behaviour played out in
measurable environmental circumstances. Therefore experiments are essential as
they allow determination of cause and affect as psychologists are interested in
finding about more about human behaviour and the mental processes that underpin
it. For example if we wanted to find out if "absence really does make the
heart grow fonder" (Does 'absence really make the heart grow founder?). Is
it enough simply to look around and make informal observations and on that basis
come to a conclusion we feel happy with? Of course in one sense it is, and as
naturally inquisitive people, we do this sort of thing all the time as a means
of forming our own opinions. But the fact of the matter is that such a process
inevitably leads different people to different conclusions - because we each
focus on different information, have different experiences, have different
agendas. Thus some people think "absence really does make the heart grow
fonder" while others think the opposite, that "Absence leads the heart
to wander"; or "Out of sight, is out of mind". To know which is
correct or when each is correct and, more importantly, why, we need to act as
scientists, not lay-scientists. Using the scientific method to answer such
questions differentiates psychology from other disciplines that address similar
questions. The scientific method is a procedure for acquiring and testing
knowledge through systematic observation or experimentation (e.g., through use
of empirical methods) and plays an essential role in achieving the
goals/objectives psychology has set out for itself. Psychology sets out to:-
╥ scientifically study behaviour and mental processes ╥ promote
human welfare Research is 'any honest attempt to study a problem systematically
or to add to man's knowledge of a problem' (Penguin Dictionary of Psychology)
The goals of psychological research are: ╥ describe behaviour ╥
explain behaviour ╥ predict behaviour ╥ control behaviour In order
to investigate psychological theories, psychologist have a number of research
methods they could use. For any method there is a compromise between conflicting
advantages and disadvantages. Some of the methods available to psychologists are
experimental/scientific, field experiment, natural experiment, correlation,
observation, case study, survey, cross-sectional, longitudinal and
cross-cultural. They are not necessarily exclusive for example you can have a
cross-cultural observation. A brief explanation of a few of the methods:-
Experimental: the relationship between two things is explored by deliberately
producing a change in one variable (the independent variable, IV) and recording
what effect this has on the other variable (the dependent variable, DV). This
method is advantageous as it can be well controlled and replicated however it
can be very artificial thus making it hard to generalise to real life.
Observational: behaviour is observed in its natural environment. All 'variables
are free to vary and interference is kept to a minimum' No independent variable
is manipulated but nevertheless a hypothesis can be tested. It is most often
used with young children, wild animals, uncooperative subjects, when something
is studied for the first time and when there are ethical objections to
manipulating variables, e.g. looking at the effects of death. This method boasts
high ecological validity and if the observer remains undetected most
experimental effects are avoided e.g. experimenter bias and demand
characteristics. However you can't infer cause and effect, there are a lack of
controls and it can't be replicated. Case Study: detailed account of a single
individual: personal history, background, test results, ratings, interviews and
so on. It is advantageous as it relates to real life, gives rich qualitative
data and may be the only way to study atypical behaviour. On the otherhand it is
time consuming and expensive, is not very scientific, is unstructured,
unreplicable and unreliable. A limited sample also makes it hard to generalise
to the population as a whole. In conclusion psychologists do experiments as they
are interested in finding more about human behaviour and the mental processes
that underpin it. Experiments are needed in order to do this as observation is
not very reliable were as experiments are scientifically based and usually allow
determination of cause and affect thus helping to solve the many mysteries of
life.

BibliographyIntroduction to Psychology, Eleventh Edition, Harcourt Brace Jovanovich
DAVIDOFF, L.L., 1981, Introduction to Psychology, McGraw-Hill Inc HAYES, N.,
1994, Foundations of Psychology - an Introductory Text, Routledge HEIMAN, G.A.,
1995, Research methods in Psychology, Houghton Mifflin Company ROTH, I., 1990,
Introduction to Psychology, Open University Publication http://www.langara.bc.ca/psychology/whatpsy2.htm