In this blog we will answer the question, ‘what is the cohort effect in psychology?’ and will deliver how cross-sectional and longitudinal studies vary.
What is a cohort?
Cohort is a group of people with a common or shared characteristic. These groups are most importantly used in researches for various purposes. A cohort may share the same age, date of births, similar years of birth or social experiences, same generation, areas or regions of their birth, initiating or graduating years of college or university.
The age or birth cohorts are likely to share common cultural, historical, and social influences.
These birth and age cohorts are the most common cohorts in Developmental Psychology. Historically, the term was used to describe a Roman military unit.
What is the cohort effect in psychology?
A cohort effect in psychology is the result of a research that is conducted for the specific purpose of the characteristics of the cohort that is being investigated or studied.
Cohort effects are studied in the fields Sociology, Epidemiology and Psychology.
A cohort effect arises when a research result has an impact by the characteristics of the cohort or cohorts that are being studied.
Cohort effects can affect the results of a cross-sectional research that has two or more than two groups at the same time. The cohort effects can be minimized through a longitudinal study, where the same participants can be observed and the changes or modifications that occur over time can be investigated.
It tends to study (in age cohort) how people of the same age respond to either the same stimulus or two or more stimuli at any given point in time.
The demographic cohort would study how people who live in the same area respond to a condition under study.
The characteristics the group have in common may influence findings in a research. This is because the characteristics of different cohorts vary over time due to their shared experiences, even if these experiences were very non-specific. The factor or factors that actually make a cohort are not directly impacting the individual member of the group.
What is a longitudinal study?
A longitudinal study is an observational study of a group or a person over a period of time, can be from a few years to many years. It is merely an observational study, where the targets are not manipulated, but only observed for the purpose of studying the item(s) under research and how they are impacted over a period of time. Longitudinal studies are conducted to study the cause and effect relationship.
What is a cross-sectional study?
A cross-sectional study is also an observational study and compares the results of different population groups at the same point in time.
Psychological studies tend to focus on birth or generational cohorts. Such cohorts share mutual life experiences and social trends. The historical events, arts and fads and fashion, political facts, economic conditions, and moral climate experienced can be different than the people belonging to separate generations. These kinds of cohorts can have an effect on the results of the research.
If any new gadget or application is launched and the trend of usage has to be found, then the researchers will find out the trend of how effective it was found. The participants may range from 20 years of age to 60 years of age. The result of the research included that that the people who were older than 50 years had a different approach towards the efficacy of the mobile app whereas, the younger participants had a much positive and an enthusiastic approach towards the new technology. This shows that the cohort effects are of prime importance from a research point of view.
Cross-Sectional vs. Longitudinal Research
Cohort effects are a particular issue in studies that employ cross-sectional methods. In cross-sectional studies, researchers collect and compare data from participants in two or more age-related cohorts at a single point in time.
In cross sectional studies it is not very easy to determine if the effect is due to age, gender or other demographics, but it is due to the different cohorts.
Longitudinal study can still minimize the effects of the cohort, by investigating the same participant(s) over a period of time. It records the changes that take place in them. The same participants can reply to the same question at different points in their life and thus give us valuable data as to their own changing schemas as they advance into age and thus give a trend change or the change in their thinking style. Longitudinal studies are still effective if cohorts are to be studied.
The advantage of the longitudinal method is that by studying a group of people across time, change can be observed directly, ensuring there is no concern that cohort effects will compromise the research outcomes.
On the other hand, longitudinal studies are expensive and time consuming, so researchers are more likely to use cross-sectional methods.
With a cross-sectional design, comparisons among different age groups can be made quickly and efficiently, however, it is always possible that cohort effects have influenced a cross-sectional study’s findings.
Examples of the Cohort Effect
Psychological researchers have utilized cross-sectional and longitudinal studies to measure changes in personality traits over time. For example, a cross-sectional study of a group of participants ranging in age from 16 to 91 found that older adults were more agreeable and conscientious than younger adults. In explaining the limitations of their study, however, the researchers wrote that they couldn’t be certain if their findings were due to the effects of development over the lifespan or the result of cohort effects.
In fact, there is research that indicates cohort effects play a role in personality differences. For example, a study published in the journal Personality and Individual Differences, the researcher utilized past research measuring extraversion in American college students to compare levels of this trait in birth cohorts from 1966 to 1993. The results showed a large increase in extraversion over time, showing the effect that birth cohorts can have on personality.
In this blog we have answered the question, ‘what is the cohort effect in psychology?’ and have delivered how cross-sectional and longitudinal studies vary.
Frequently Asked Questions
What is a cohort in psychology?
Cohort refers to the people who belong to the same age, or even similar backgrounds or even same graduating years in the same college.
What is an example of a cohort?
Examples of cohorts are birth and educational cohorts. Even location and racial cohorts are used, depending on the type of the research.
What type of problem is the cohort effect?
The problems that arise due to the cohort effect are the ones that impair the result of the research, these are due to the traits of characteristics of the cohorts that are being under study. This mostly happens in cross-sectional studies.
What are the biases in a cohort study?
The potential bias in a cohort study is the lack of follow up.
What are the limitations of a cohort study?
The limitations of a cohort study are the expenses borne due to long term follow up. It is also time consuming.
Titles to Read
- Research Methods in Psychology: Evaluating a World of Information (Third Edition) by Beth Morling
- Methods in Behavioral Research by Paul Cozby and Scott Bates
- Publication Manual of the American Psychological Association: 7th Edition, 2020 Copyright by American Psychological Association
- Cohort Analysis (Quantitative Applications in the Social Sciences Book 5) by Norval D. Glenn