The popular science press hosts countless reports of sex-based differences between men and women. Magazines, weekend newspapers and email inboxes teem with commentary about statistically significant differences between male and female samples on decision-making, emotion, behavior, and fMRI imaging, however guarded or hard to replicate the research findings may be. Not only are many findings on sex-based differences in the general adult population often inconsistent, minimally replicated, and difficult to apply within real life social settings, they are largely based on research on younger and middle-aged adults.
While it is often commented that women as a rule live longer than men, comparatively little else has been empirically demonstrated about the differences between older men and women. Despite the questionable scientific rigor behind many popular accounts of gender and sex, the role of sexual biology in physical aging, and of gender as a social organizing principle across the human lifespan, make sex and gender differences significant in the lives of older individuals.
A recent review article in Gerontology (Kryspen-Exner et al 2010) draws attention to the conceptual and empirical problems that impede our understanding of gender and aging. The authors argue that, as individuals advance in age, the relationships between multiple social and biological factors grow increasingly complex, making it harder to explain gender differences with “models of linear cause and effect chains” (ibid). Thus, the authors advocate for a comprehensive bio-psycho-social model of aging (BPS) that incorporates biological sex, social gender roles, and other factors that shape individual human development. Through this model, review the current state of research on sex and gender differences in aging.
The authors address “four preconceptions” underlying work on aging and gender. First, they amend the popular understanding of the labels sex and gender as separate domains that respectively address biological and social differences. In truth, the biological and socio-cultural aspects of sex and gender cannot neatly be separated. This is not to say that all cultural differences can be reduced to biological differences, or that all biological differences result from social conventions. Instead, the biological and the social interact reciprocally. Secondly, the authors call attention to the contributions of developmental psychology in pointing out that “old age” can’t be treated as a distinct phase, but a term that can be applied to multiple developmental processes that take place throughout the life course.
Thirdly, the authors point to the need to incorporate questions of gender within “active aging” approaches, which focus on beneficial aspects of aging and, the authors state, are consistent with a BPS approach. BPS models of aging show that active aging is not reducible to measures of wellbeing or quality of life. From a BPS model, the notion of active aging evidences the interaction between the biological, psychological, and social, as studies show that individuals who take an active aging approach receive cognitive, social, and physiological benefits. The authors point to how the social organization of gender leads to very different ideals of active aging for men and for women, pointing for the need to apply considerations of gender to active aging.
The fourth preconception addressed is demographic change. As mentioned above, one of the only widely-attended aspects of gender and aging is the differences in life expectancies between women and men. At the same time, the authors point to the shrinking of this gap, and to how it has been overlooked that, while women tend to live longer, there is research to suggest that men in general experience a greater number of years in subjectively judged good health.
The authors invoke these preconceptions to address research on physiological sex differences, psychology, and psychopathology. Much of the limited research on physiological sex differences in older adults has been equivocal and conflicting. Given that sex differences are overlapping and gradual even in domains observable in the younger adult population, that such differences are not replicable in older adults is logically unsurprising, if contradictory of “common-sense” views of sex and gender.
The interaction of brain and behavior makes it even more difficult to parse out sex-based differences from other social influences, such as men’s greater tendency to smoke and engage in aggressive and risky behavior, or women’s disproportionate labor in uncompensated domestic work and caregiving. There are general average differences in male and female brains in terms of size and proportion of grey-to-white matter, but findings on the cognitive and behavioral correlates of this are conflicting and equivocal, and there is still a relative lack of consistent findings on the influence of aging on the physiology of the brain. Results on memory performance in aging adults have been mixed, with some studies showing better performance among women than men, some showing the inverse. (A meta-analysis incorporating unpublished findings would seem to be particularly valuable.) Also non-generalizable have been findings of “differences between males and females in language-related cortical regions” (Kryspen-Exner et al, citing Wallentin 2009), as individual physiological compensation and brain plasticity make it difficult to interpret functional differences in brain architecture across the lifespan.
Sex hormones, which exist in great individual variety but significant overall sex differences, change over age, but there is minimal empirical data on hormone change and the aging brain. Further, as controversies over post-menopausal Hormone Replacement Theory suggest, findings on the role of hormones in aging have been mixed, leading to conflicting ideas of “best practices.” (The article only presented findings on estrogen in women and androgens in men, despite the developmental significance of both across genders, likely a result of biases in the literature.) Further, in fMRI studies, the “older adult” sample is typically significantly younger than how the term is used by gerontologists.
Psychological findings on aging and gender have also been mixed. The authors note a lack of longitudinal studies of gender difference, as well as the mass of confounding social and physiological variables that make such work difficult to execute. Gender-based differences in earlier-life education, role differences, “lifestyle habits” not only confound analysis but undergo profound change during individual lives. Any differences in cognitive styles across aging men and women are similarly difficult to establish. As the authors pithily note ,the likelihood that individuals “do not solve cognitive tasks or run through daily routines in the same way in every stage of our lives can easily be observed in the normal course of life, but is hard to demonstrate in empirical findings.” (6) The authors address the similarly inconsistent findings on aging, gender, and intelligence, but, as they note, measures of intelligence do “not predict stable effects on the behavioral level” –to say nothing of the utter lack of consensus on the meaning, utility, or scientific validity of the very concept of intelligence. Consistent with “active aging” hypotheses, the authors do not that older adults seem more adept at everyday problem solving, as older adults across genders have been found to “combine emotion regulation strategies and instrumental approaches more efficiently” than younger individuals.
How does a review that points out the conflicting and equivocal nature of findings of gender differences help advance our understanding of this issue? The authors do so in many ways. As their review incorporates multiple disciplines that have approached some of the same questions, the authors are able to point out confounding variables addressed by different schools of research, which offers the possibility to improve the conceptual validity across sciences.
Gender differences may be impossible to reduce to common-sense stereotypes, but have research and clinical significance. For instance, the authors re-examine gender differences in the prevalence of psychiatric disorders, one of the few domains other than sexual anatomy where, at least within younger cohorts, sex differences have been stable and consistent across studies—to take a more famous example, the differences in age of onset of schizophrenia between women and men. Here, the significance of the lack of understanding of the role of aging and gender is a direct impediment to medical and social research. The authors also refer to studies (such as Crowe et al 2003) which have pointed to gender differences in the benefit gained participation in certain activities like volunteering and high culture. Rather than applying either a purely deconstructionist approach, or an overly simplistic one that lends cliché a scientific veneer, the authors advance a more rigorous and elaborate scientific framework that is useful for critical work on gender, “pure” research, and clinical research.
Kryspin-Exner, E, Lamplmayr, E and Felnhofer, A (2011). “Geropsychology: The Gender Gap in Human Aging – A Mini-Review” Gerontology, e-pub ahead of print. PMID: 21124020
Crowe M, Andel R, Pederson NL, Johansson B, Gatz M (2003). Does participation in leisure activities lead to reduced risk of Alzheimer’s Disease? A prospective study of Swedish Twins. Journal of Gerontology Series B 58:249-255.
Wallintin M (2009). Putative sex differences in verbal abilities and language cortex: a critical review. Brain and Language 108: 175-183.