498 Adult Development and Aging
well as opposed to the usual focus on the •four D•sŽ (disease,
disability, death, and dementia). Many of the factors that
health psychologists study are related to becoming a •suc-
cessful agerŽ and, as we have discussed, modifying risky be-
haviors can contribute to that process.
Social Support
This relationship has been well-documented. Adequate social
support reduces morbidity (Bosworth & Schaie, 1997; Vogt,
Mullooly, Ernst, Pope, & Hollis, 1992), mortality (Berkman
& Syme, 1979; Fratiglioni, Wang, Erickson, Maytan, &
Winblad, 2000; Strawbridge, Cohen, Shema, & Kaplan,
1996; Williams et al., 1992), physical functioning (Kaplan,
Strawbridge, Camacho, & Cohen, 1993), and marital status
(K. Martin et al., 1995; Tucker, Friedman, Wingard, &
Schwartz, 1996), which has differential impact for men than
for women (Tucker, Schwartz, Clark, & Friedman, 1999).
One possible mechanism by which social support may lead
to successful outcomes is friends and relatives encouraging
less risky behaviors and encouraging healthy behaviors
(Umberson, 1987). A second mechanism may consist of the
person•s social network providing necessary information or
encouragement for seeking preventive health care services
such as a prostate cancer screening and treatment (Berkman,
1995). Third, the social network may provide the patient with
information from other people who have direct or indirect
experience with a problem or medical condition.
Self-Rated Health
Self-rated health has been found to be a predictor of mortal-
ity (Bosworth et al., 1999; Idler & Benyamini, 1997) and
morbidity (Bosworth & Schaie, 1997). While self-rated
health captures scores of summary information about health
status, it does not represent the speci“c disease status of an
individual. What is still not understood is the meaning of self-
rated health as a covariate and how it in”uences aging re-
search “ndings (see Siegler, Bosworth, & Poon, in press).
Objective assessment of health (physician examination
combined with objective diagnostic methods) represents the
gold standard. On the other hand, objective data collection is
often either impractical, unethical, or both, given cost-bene“t
considerations and the possibility of risk to the study partici-
pant. Moreover, important data may be lost if we insist on ob-
jective measurement of disease; that is, retrospective data,
archival data, and data collection that achieves large samples
and/or representative samples but does not permit direct sub-
ject contact. Self-report is necessary where self-assessment is
central to the research question; in studies, we are directly
concerned with how subjects rate themselves in relation to
objective measurements. It has been argued that self-report is
a questionable practice when new data collection is possible
and when the objective is to identify and de“ne a few tar geted
diseases with high levels of sensitivity and speci“city
(M. Elias et al., 1990), unless of course, subject risk is unac-
ceptably high in relation to bene“ts.
Because self-report may be the focus of health-aging re-
search or a necessary evil, it is important to understand its
limitations. Costa and McCrae (1985) point out that the em-
ployment of self-ratings as •proxy measures of objective
health statusŽ is common and that investigators often justify
this approach based on statistically signi“cant correlations
between physician-rated health and self-ratings, even though
those correlations are modest. A series of classic studies has
shown that self-report of disease and disease itself are not
veridical and can be in”uenced by neuroticism and many
other social-psychological factors, including disease (e.g.,
Costa & McCrae, 1985). We can not ignore information that
can be gained from archival data, retrospective studies, or
large sample mail or phone survey data because objective as-
sessment of disease is not possible. However, the investigator
is charged with the responsibility of establishing the validity
of the self-report measuring techniques used. Where
possible, however, the ascertainment of the reliability of self-
report data via medical case records, follow-up with physi-
cians and other informants, and treatment history is highly
desirable.NEW DEVELOPMENTS IN GENETICS AND AGINGHow and where do aging and health psychology researchers
learn to use the exploding new information, and where do
we have data already applied to aging problems? While
genes are “xed at birth, they can have dif ferent effects at dif-
ferent ages and interact with environments differentially at
different ages, and furthermore, behave differentially in dif-
ferent populations. There are age-related changes in heri-
tability, that is, in the amount of variance in a population due
to genetic variance. In addition to age related changes in her-
itability, it is quite possible that different genes or different
combinations of genes are operative at one part of the life-
cycle and inoperative at another.
McClearn and Heller (2000) discuss intersections of
genetics and aging. Psychologists look to genetics for the
sources of individual differences in rates and patterns of
aging. They illustrate their discussion with “ndings from
the Swedish Adoption/Twin Study of Aging that has the ad-
vantage of twins raised apart by unconfounding genetic and
environmental similarity in comparing twins raised together
and raised separately. Greater resemblance in twins raised