Why are laboratory experiments so important in psychology?

Laboratory experiments play a major role in psychological research. They allow us to find a cause and effect relationship between variables that would not be possible with many other research methods.

Laboratory experiments use different conditions to measure the effects of increasing the manipulation of the independent variable. The variable that is measured is called the dependent variable. Often, laboratory experiments consist of two conditions; the experimental condition and the control condition. In the experimental condition, the independent variable is manipulated, whereas in the control condition, it is not. This allows us to see how the independent variable affects the dependent variable and we can therefore see a direct cause and effect relationship.

Laboratory experiments also allow for tight controls which prevent any extraneous variables from affecting the results, as these could possibly affect the results. If extraneous variables were not controlled for, the reliability of the results gained would be reduced as the same or similar results would not be collected if the research was repeated. In general, because of the controls put in place, the level of reliability is relatively high for laboratory experiments.

Laboratory experiments also produce quantitative data. This means that analysis of the results is more objective as fewer subjective interpretations can be made. However, this data does not provide an explanation as to why the results occurred but do allow us to see a relationship and find any anomalies.

Laboratory experiments do lack ecological validity. If ecological validity is present, a method is representative of a real-life situation. Laboratory experiments lack this because the environment is artificial. This means that participants may not behave in the same way as they would in a real-life situation and so the results become less valid. An example of this would be Loftus and Palmer (1974). In the study, participants were asked to watch clips of traffic accidents then answer questions from a questionnaire. They were asked to estimate the speed of the cars in the collision by a critical question that had a verb changed to make leading questions. It could be said that ecological validity is lacking from this piece of research because participants watched clips of collisions and so their levels of adrenalin would not have been massively increased and so they wouldn’t have experienced the same biological and emotional reaction as they would in real-life. This is machine reductionism.

In conclusion, I believe that laboratory experiments are possibly the most important pieces of research in psychology due to the chance to see a direct cause and effect relationship and also reduce the effects of extraneous variables. They allow for high reliability and collect objective data. However, the lack of ecological validity does reduce the usefulness but I think it is more important to have reliability and show relationships between variables rather than be representative of a real-life situation.



Loftus, E. F. & Palmer, J. C. (1974) Reconstruction of automobile destruction: An example of the interaction between language and memory. Journal of Verbal Learning and Verbal Behaviour, 5, 585-589.

This entry was posted in Uncategorized. Bookmark the permalink.

8 Responses to Why are laboratory experiments so important in psychology?

  1. rebeccag92 says:

    I agree that laboratory experiments do provide the most reliable results but is this worth the sacrifice of validity?
    As psychologists are we not trying to study and find answers about human behaviour as it naturally occurs: which debatably laboratory studies do not do, they study human behaviour in a controlled and artificial environment; far removed from the real world. I would then argue that can we really generalise results from laboratory studies to the real world? They are not observing natural behaviour and as such provide no answers to questions about natural human behaviours. Rather they provide answers about human behaviour when it is manipulated by control measues.
    Laboratory studies also dehumanize particpant’s; behaviours are not indivudally recorded but rather they are looked for; surely this makes them susceptible to investigator bias. When a researcher is looking for evidence to support his theory we could argue that this striving could lead to them becoming bias and commiting type 1 errors; observing a behaviour, pattern or effect when there is in fact no such objective effect.
    One of the greatest strengths of laboratory experiments is that they can be replicated, but is this really necessary for the study of human behaviour? Something that is highly subjective, relative and susceptible to change. In real life do we react to the same stimulus in the exact same way more than once? For example do we approach every relationship in our lives in the same way? Do we react identically to every loss we suffer? Basically our behaviour changes in accordance with the world around us, this occurs naturally and this is not a practise I believe can be validly replicated or observed in a laboratory experiment.

  2. rebeckiny says:

    Laboratory experiments are in my opinion the first stepping stone into deciphering a certain behaviour. Without them, like you have said, we can’t establish causal relationships and without these we have no foundations for the meaning behind our behaviours which is the aim of all our research. However, I do agree with the comment above that a laboratory study that has little to no validity has little value to the greater community. There needs to be a balance between all of these factors for a lab study to be successful, a study that has high reliability but that cant be generalised to anyone else has no practical application and even if it does find a relationship, it means that it cannot be proven for the rest of the population anyway. Demand characteristics are also another issue in laboratory studies because if the behaviour is not natural then the study is measuring inaccurate behaviour patterns that not only will produce wrong findings, but then cant be generalised anyway

  3. psuf50 says:

    Whilst laboratory experiments may be the most reliable, they cause a huge amount of problems, especially in terms of validity. We can never be completely sure that participants are acting in a way they normally would meaning that its difficult to apply the findings to real life situations and it’s also difficult to ensure you measure what you intend to measure. Also, whilst the reliability may be higher than it would for other types of experiments, it still isn’t entirely accurate. Bias is also likely to occur, especially by the researcher who may influence the experiment in order to make his theory seem correct. They also pose more ethical issues than some of the other experiment types
    So, whilst I agree that laboratory experiments are important in psychology and may be needed to test some things which cannot be tested in other circumstances, I believe that they should not be considered the most important as other methods such as naturalistic observations may prove to be better.

  4. djaic says:

    Laboratory experiments are important in psychology, they are the most scientific, extraneous variables are tightly controlled therefore cause and effect are able to be established. If they were not used, we’d see relationships but laboratory experiments are vital to move correllation onto causation.

    However as you’ve already stated their usefulness in psychology is very much limited, as psychology is the study of mind and behaviour, lab experiments are unhelpful as both mindset and behaviour change once people know they’re taking part in a lab experiment. For example very well known experiments like Milgrams obedience experiment and Asch’s comformityexperiment were laboratory experiments, so how do we know that these results can be generalised? Or demand characteristics were not present? It can never be certain that these experiments are a true reflection of how people would behave in everyday life.

    lLooking at subjectivity, it can be argued that as psychology is theory driven it can never be subjective as we are constantly looking for evidence which supports out theories (Popper). However where possible lab experiments which use the double bling method are much more objective than other methods.

  5. sigmafreud says:

    Foremost, laboratory experiments offer an unparalleled degree of control over a given set of variables, except of course confounding or extraneous variables which often lie outside of the experimenter’s control. Naturally, this degree of control means that the external validity is extremely limited – as you’ve stated.
    Nonetheless, they are extremely important in the foundation of the experimental method. The establishment of causation between variables is more readily identified than those presented in a more naturalistic setting. Whilst it is true that the presence of demand characteristics do become problematic in such a heavily controlled environment as that of a laboratory experiment, the high internal validity cannot be denied. Of course, the question remains; is the high internal validity worth the relatively low external/ecological validity? Is such a controlled environment worth such a compromise?

  6. souf18 says:

    I agree with you. Laboratory experiments are the most important and effective way to find out how one variable effects another but only when done right. When an experiment has high control and no extraneous variables can effect the outcome of the experiment it provides reliable results. However it is very difficult to control all these factors, you may not be aware of an extraneous variable effecting the results. With high control establishing a cause and effect, there is also the problem of ecological validity as you said. All in all I agree with the majority of what you said, that experiments are a very effective method.

  7. There are many kinds of occupations that one could select from nowadays. It may take that you simply even though to decide on the most effective to suit your needs however, you realize there will be something that can be done.different types of psychology

  8. Renate Woodling says:

    I am always fascinated with psychology that is why i took a Bachelors Degree on psychology. ..

    <a href="Brand new post on our personal online site

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s