causal influences in social processes because
they can better pinpoint the temporal order of
events, conditions, and experiences. Of course,
even the best longitudinal data are unlikely to
firmly resolve many substantive issues of this
sort, in that there will still be relevant variables
that are omitted from the design, limitations of
sampling, measurement imperfections, and
other impediments to drawing causal infer
ences. On the other hand, longitudinal data
permit one to address far more interesting
questions than is possible with cross sectional
data. Longitudinal data are also essential for
examining issues linked to life course theory,
which focuses primarily on the developmental
or age related patterns of change over the life
span that are embedded in social institutions
and subject to historical variation and change.
Generally, in research on aging and the life
course virtually all the best designs for study
ing life course phenomena are longitudinal
because they allow one to conceptualize more
accurately the nature of the substantive phe
nomenon and locate lives in time. This require
ment strongly implies the need for repeated
longitudinal studies based on sequences of
birth cohorts (see Alwin et al. 2005). Still, there
are several major impediments to drawing
inferences about change and its sources, even
with longitudinal data. Perhaps the most fun
damental of these is to be able to locate events
and processes in time and specify their causal
relation to consequences or outcome variables,
while taking other causal factors into account.
Finally, longitudinal designs also fit well
with the newer perspectives linking the demo
graphy of the life course to human develop
ment. If one takes a lifespan developmental
perspective with respect to the study of pro
cesses of aging (including life cycle processes
and life course events and transitions) and
recognizes that human lives are embedded in
social and historical contexts, it is clear that a
range of ontogenic and sociogenic factors
impinges on peoples lives in ways that affect
their well being. Capturing the interlocking
trajectories or pathways across the life span
that are marked by sequences of events or
social transitions which impact upon indivi
dual lives and relating them to measures of
health and functioning (among other things),
as well as linking them to underlying social
processes, is an important focus of a great deal
of research on aging, and these are the major
theoretical concerns that drive the present dis
cussion of longitudinal methods for the study
of aging and human development.
SEE ALSO: Aging, Demography of; Aging and
the Life Course, Theories of; Aging, Sociology
of; Life Course; Life Course Perspective
REFERENCES AND SUGGESTED
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(2005) Modeling the Effects of Time: Integrating
Demographic and Developmental Perspectives.
In: Binstock, R. H. & George, L. K. (Eds.),
Handbook of Aging and the Social Sciences, 6th
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Alwin, D. F., McCammon, R. J., & Hofer, S. M.
(2005) Studying Baby Boom Cohorts within
a Demographic and Developmental Context:
Conceptual and Methodological Issues. In:
Whitbourne, S. K. & Willis, S. L. (Eds.), The Baby
Boomers at Midlife: Contemporary Perspectives on
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Mason, W. M. & Fienberg, S. E. (1985) Cohort
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Scott, J. & Alwin, D. F. (1998) Retrospective Ver-
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Jr., G. H. (Eds.), Methods of Life Course Research:
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Thousand Oaks, CA, pp. 98 127.
Young, C., Savola, K., & Phelps, E. (1991) Inven
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Sage, Newbury Park, CA.
aging, mental health,
Linda K. George
Social factors are strongly implicated in men
tal health and well being throughout life,
including old age. Sociologists argue that