Longitudinal Study, Essay Example

The official title of the original study appears to be “The Seattle longitudinal study: A 21-year exploration of psychometric intelligence in adulthood”.

The sole listed primary investigator of the original study is K. Warner Schaie, though Sherry L. Willis has since joined the project as an additional primary researcher.

The study has included 5676 adults in total through various phases of investigation that began in 1956 and are planned to continue into December of 2013. The sexes are nearly evenly divided at 2977 women and 2696 men with the remaining three participants unaccounted for in sexual disclosure. There were a total of 884 subjects during the testing run between 2008 and 2010. Some statistics from 2011 include the oldest participant being 103 years old and the youngest 36. There remained 22 of five hundred original subjects who have been with the study since the beginning, and the baby-boom generation were represented by about 700 people. Subjects have been randomly selected from the Group Health Cooperative of Puget Sound (GHC).

The study has been conducted in intervals that began in 1956 and continue today in the Seattle area.

The longitudinal phase design of this study has allowed for a continually evolving structure as more research becomes available and new theories are developed. All stages of the study were primarily composed of survey and inventory models. Each round of testing brought a variety of alterations to address observed deficiencies, such as initial modifications to address randomness problems in the sample selection process. Additionally, a battery of the latest relative psychometric and associated measures has been included over time. Each of these components included an appropriate analytical stage as defined within the specific test.

This study has five stated primary objectives:

1. Is intelligence change uniform during adulthood or does it occur in different patterns?
2. What is the age and scale at which intellectual ability is significantly decreased?
3. What is the pattern and size of ability differences between generations?
4. What factors account for the individual differences in ability changes due to age?
5. Can educational interventions cause a reversal in age-related decline?

The findings thus far in relation to each objective are as follows:

1. Intelligence changes during adulthood are not uniform and can occur in various patterns between individuals.
2. Decline generally begins at age 60 but is not consistently observable until age 74, when an average drop in psychometric ability of about 0.2 standard deviations can be observed. The change by age 81 is one standard deviation on average for most measures.
3. The study has revealed a significant and reliable difference in psychometric abilities between age groups. However the magnitude of these changes has not yet been significantly demonstrated.
4. Implicated variables include chronic and/or cardiovascular disease, socioeconomic environment, intellectual environment, flexibility of midlife personality, cognitive ability of spouse, and maintenance of perceptual processing velocity.
5. Yes, interventions have been shown to reverse cognitive decline, including within two- thirds of those who received cognitive training.

Two of the most interesting findings are the usefulness of education and the lateness in which major deficiencies are seen. The public seems to have a general understanding that cognitive decline due to age is irreversible and that it becomes significant much earlier in life than was found in this study. Perhaps educational material for the public would help to spread word of potential treatments and accurate information about age-related cognitive decline.

This study is significant for many reasons, including the evolved design, a large sample size, and the inclusion of a nearly innumerable amount of intellectual indicators. All people are subject to decline with age and the more we know the better we can attempt to prevent and/or reverse it.

Reference

Bosworth, H. B., & Schaie, K. W. (1997). The relationship of social environment, social networks, and health outcomes in the Seattle Longitudinal Study: Two analytical approaches. The Journals of Gerontology Series B: Psychological Sciences and Social Sciences, 52(5), P197-P205.

Caskie, G. I., Willis, S. L., Warner Schaie, K., & Zanjani, F. A. (2005). Congruence of medication information from a brown bag data collection and pharmacy records: Findings from the Seattle Longitudinal Study. Experimental Aging Research, 32(1), 79-103.

Gerstorf, D., Ram, N., Hoppmann, C., Willis, S. L., & Schaie, K. W. (2011). Cohort differences in cognitive aging and terminal decline in the Seattle Longitudinal Study. Developmental Psychology, 47(4), 1026.