To test this hypothesis, the researchers recruit participants who are in their mid-40s to early 50s.
They collect data related to current physical fitness, exercise habits, and performance on cognitive function tests.
He used the data to spot trends over the years and understand his colonies' health and economic viability.
Steve McAlister / The Image Bank / Getty Images
Types of Longitudinal Studies
Longitudinal studies fall into three main categories.
Benefits of Longitudinal Research
A longitudinal study can provide valuable insight that other studies can’t.
Because the participants share the samegenetics, researchers chalked up any differences toenvironmental factors.
Note that adoption agencies no longer separate twins, so such studies are unlikely today.
Longitudinal studies on twins have shifted to those within the same household.
Cost
Longitudinal studies require time and are often quite expensive.
This tendency, known asselective attrition, shrinks the sample size and decreases the amount of data collected.
If the final group no longer reflects the originalrepresentative sample, attrition can threaten thevalidityof the experiment.
Validity refers to whether or not a test or experiment accurately measures what it claims to measure.
Results from this study were still being compiled into the 2000s.
That depends on what researchers are investigating.
A researcher can measure data on just one participant or thousands over time.
Piccinin AM, Knight JE.History of longitudinal studies of psychological aging.Encyclopedia of Geropsychology.2017:1103-1109. doi:10.1007/978-981-287-082-7_103
Terman L.Study of the gifted.
In:The SAGE Encyclopedia of Educational Research, Measurement, and Evaluation.2018.
doi:10.4135/9781506326139.n691
Sahu M, Prasuna JG.Twin studies: A unique epidemiological tool.Indian J Community Med.
2016;41(3):177-182. doi:10.4103/0970-0218.183593
Almqvist C, Lichtenstein P.Pediatric twin studies.
In:Twin Research for Everyone.
Warne RT.An evaluation (and vindication?)
2020;158(1S):S65-S71.
doi:10.1016/j.chest.2020.03.012
Caruana EJ, Roman M, Hernandez-Sanchez J, Solli P.Longitudinal studies.J Thorac Dis.
2015;7(11):E537-E540.
