Case Study # 1: Bias in Psychological Research
In this case I ask that you wrestle with the issue of psychological research bias. This is related to the last
case in that a bias of all research studies can be traced to the theoretical framework undergirding the
study. It is important that you understand what using research to support specific statements means.
We are reviewing a great deal of material and the textbook attempts to put it all together in a way that
makes sense and provides a consistent picture. But what if the author has a bias that is shaping the
material or the weight given to various perspectives? How would you know that what you are taking
away from this course is in fact a defensible representation of the current state of knowledge about
human development? EPS 580 I will boldly assert that all research has its biases and this is unavoidable…humans have predispositions,
beliefs, and values which influence everything they do; and in addition, research grows out of a world view
or paradigm that also contributes a type of bias. As a consumer, what should you look out for in making
judgments about scholarly work? As a student reading the textbook assigned for this course, what
conceptual biases must you be aware of in order to put the book’s information in context?
The following excerpt (Banyard, 1999) describes one aspect of conceptual bias that I suspect we all
succumb to most of the time, the idea of normal or average. This is a concept that is throughout this and
any other textbook on human development, but we must be sensitive to the underlying problems with
taking this concept too literally. The purpose of this case is simply to alert you to this paradigm or world
view bias that is present in social science research and encourage you to not take everything as literal. In
the world of science and especially social science there is a paradigm that exists behind research and the
concepts we use to make sense of our world. Can we be objective?
A problem for psychology is that it attempts to adopt a detached academic and ‘scientific’
standpoint. Scientists pretend to be objective, that is, free from bias and free from value. But this
cannot be so. As we have seen above, you inevitably view the world from a particular perspective,
that of yourself and the various groups to which you belong. I cannot be free from bias because my
behavior and conversation are affected by the way I interpret the world and the opinions that frame
these interpretations. Sometimes psychologists attempt to take a balanced view. The problem with
this attempt is that it presumes that we all agree where the middle of two opposing arguments, and
hence the balance, should lie. To take an extreme example, imagine taking a balanced approach to
child sexual abuse. Should we position ourselves midway between someone who opposes adult–
child sexual contact and someone who advocates it (a pedophile)? This is clearly nonsense. So we
have to accept that the choice of the balancing point is not a matter of detached objectivity, but a
EPS 580 matter of opinion. Balance and objectivity are not possible. What is important is to be aware of your
perspective and the limitations it imposes on your view. Psychology, unfortunately, is often blind to
its perspectives and their biases. In the next section we will go on to look at three sources of bias in
psychology that come from the way it carries out its investigations; average people, the differences
between and within groups, and invisible people. Average people
A large number of psychological studies are designed to look for measures of differences between
groups of people or between conditions. These studies rarely look at individual diversity as one of
the key features. It is more common for the ‘subjects’1 to be treated as identical people and for the
‘subject variables’ (psychology-speak for our individuality) to be kept to a minimum or ignored. This
means that the conclusions of the research can only produce statements about how ‘most people’ or
the ‘average person’ will behave. But who is this average person, and what does he or she think,
feel and do? And, is it reasonable to assume that most people are ‘average’?
Engineering psychologists (ergonomists) measure the dimensions of different parts of the body to
see what is the best possible design for machinery. Designing a car seat is a good example. The seat
needs to be comfortable for most people that would want to drive the car. The obvious strategy
would be to design the seat for the ‘50th percentile person’, the person who is average on all, or
almost all, of the body dimensions. The dimensions include standing height, sitting height, arm
reach, knee height, shoulder breadth and so on. It is unlikely that any one person would be exactly
average on a whole battery of dimensions, but we could reasonably expect a number of people to be
1 There is some controversy over whether to use the term ‘subject’ or ‘participant’ to describe the people who are studied in
psychological investigations. In my opinion it is only appropriate to describe someone as a participant if they have some say in
what is going on and have some ownership of the data. If they are just brought into the laboratory and have things done to
them and measures taken from them, then the best term to describe them is probably ‘subjects’.
Retrieved from http://site.ebrary.com/lib/nau/Doc?id=5002869&ppg=94. Copyright 1999. Routledge. All rights reserved. EPS 580 in the middle third of most dimensions. Unfortunately, this is not so. A study by Daniels (cited in
Gregory and Burroughs, 1989, p. 65) investigated the body dimensions of 4,000 flying personnel on
just ten dimensions. They found that not one person fell in the middle third for all measurements.
Nobody had an average body, or to put it another way, there was no average person.
Another example of this individual diversity can be seen in the diagrams of stomachs shown below
(Figure 4.1). A comparison of the drawings of twelve ‘real’ stomachs with a text-book drawing of a
‘normal stomach’ shows that none of the stomachs are ‘normal’ and many do not even look like
stomachs. EPS 580 Figure 4.1 The ‘average’ stomach and real stomachs If there is no such thing as an average body, it seems rather unlikely that there is such a thing as an
average personality or an average behavior pattern. When we talk about averages we mean that we
have added up all the scores and divided by the number of measurements taken. This average score
does not have to describe the behavior or personality of even one person. So, when psychology
texts and research papers talk about how people behave, they are referring to a theoretical average
person, and it might well be that no real person actually behaves like this. Differences between groups and within groups
One of the problems that comes from looking at average scores is that you can come to some
inappropriate conclusions about group differences. For example, there is a lot of interest in the
differences in performance between men and women. If you take the average score of men on some
dimension and compare it with the average score of women you might find a small difference.
However, the spread of scores among men and women far outweighs the difference between the
two groups. Also, with regard to gender differences in children, for example, reviews of the research
into cognitive ability and social behavior have consistently found that there are very few measurable
differences, and in the cases where there is a difference the effect is very small (for example,
Woolley, 1910, cited in Williams, 1987; Maccoby and Jacklin, 1974).
Look at the example distributions below (Figure 4.2). They show the different distributions of boys
and girls on a made-up variable of ‘binkiness’. You will see that girls have an average binkiness
score a little higher than boys, but that the distributions overlap so much that it would be impossible
to predict a person’s binkiness score just by knowing their gender. An analysis of the research on the
development of social and cognitive behavior found that male– female difference accounted for only
1– 5 per cent of the variance in the population (Deaux, 1984). This means that gender is a very poor
predictor of how an individual will behave.
EPS 580 Figure 4.2 Distributions of ‘binkiness’ in boys and girls Invisible people
A further problem with the idea of the ‘average person’ is that some groups of people are excluded.
Any minority group is, by definition, going to have only a small effect on the average. These groups
of people are therefore excluded from the discussions about behavior and experience. For example,
the majority of people in this country have mainly heterosexual relationships, but a significant
minority have same-sex relationships. The ‘average person’ is clearly heterosexual, but if we just
describe the behavior of these average people we are ignoring the behavior and experience of a
significant minority. EPS 580 Our concepts of average or normal behavior contain a number of assumptions and biases. A study
by Broverman el al. (1971) into what doctors expect of healthy people illustrates this problem. In
this survey, doctors were asked to identify the terms that best described (a) a healthy adult, (b) a
healthy man, or (c) a healthy woman. There was good agreement between the doctors on what
were the characteristics of each group. The characteristics of the healthy man were judged to be
very similar to the characteristics of a healthy adult, which is what we would expect. The
characteristics of a healthy woman, however, were significantly different from the characteristics of
the healthy adult. One of the inferences we can draw from this is that when doctors think of an
‘adult’ they are assuming that it is male. Although the term appears neutral, it carries some hidden
assumptions and biases.
So, there are adults and there are also women. If we take this a step further, I would suggest that
there are also the following assumptions in our language:
there are people and there are Black people;
there are people and there are gays and lesbians;
there are people and there are disabled people. I could go on, but I do not want to labor the point. We need to be aware, then, that apparently
neutral terms like ‘people’ actually contain a lot of assumptions.
When we use the term people, we do not mean ‘all people’ but just ‘average people’. What this
means is that a large number of people are invisible in psychology texts. In fact, we do not even
notice that they are absent. This would not matter if the experiences of these people were the same
as the experiences of the ‘average person’, but unfortunately, they are not. The problem for
psychology is that if these invisible people are to be included, the results of studies and the
structure of theories might be very different. We will come back to this point later in this chapter
when we look at some replications of famous studies carried out in countries other than the original.
EPS 580 Summary
To put the above in a nutshell,
the average person does not exist, and referring to averages of behavior and experience
masks the differences between individuals;
the perceived differences between groups of people are based on differences in average
scores, and these differences are often much smaller than the differences between individuals
within the groups;
by reducing ‘subject variables’ and looking at average performance some groups of people are
made invisible within psychology.
For this case, I ask that you consider the above material and reflect upon what impact this will have on
your interpretation of the material from this course. Please compose a 2-page minimum paper on this
topic. There is no penalty for writing more, and you may have to in order to answer all the questions
appropriately, however, please do not write more than 4-pages. Papers do not need to be in APA
format but they do need to include APA-style references, be in 12 pt. Times New Roman font, and
double spaced. DO NOT INCLUDE THE QUESTIONS IN YOUR PAPER. Please explicitly include
references to the course materials. If you do not, you cannot get over 20 points on this
assignment.
1. What is the relevance of this material to your understanding of human development?
2. Has Berger (the author of your textbook) done a good job of alerting you to the non-existence of
the hypothetical normal individual? Why or why not?
3. Why do you think certain groups remain “invisible” and why is psychology reluctant to include these
groups? Note: researcher are as biased as their samples; as an example, APA created a Resolution on
Poverty and Socioeconomic Status in 2000 that reflected the profession’s cognitive distancing from
the poor and the consequent invisibility of low-income persons within psychological research. These
unintended biases caused gaps in the literature and research agenda for the entire profession References
Banyard, Philip. (1999). Controversies in Psychology. Retrieved from
http://site.ebrary.com/lib/nau/Doc?id=5002869&ppg=98. Copyright 1999. Routledge. All rights
reserved.
