Sex Differences In Expectancy Research Articles

Mechanisms of Fetal Programming of Adult Hypertension

Epidemiological and experimental studies suggest that the in utero environment plays a critical role in the development of adult disease, including cardiovascular disease and hypertension. Intrauterine growth retardation produced by maternal undernutrition or exposure to maternal glucocorticoids during critical periods of organogenesis impairs fetal growth and produces offspring that develop hypertension early in life.1 This concept of “fetal programming” was first proposed by Barker et al2 to describe the relationship between low birth weight and subsequent risk for the development of cardiovascular disease and hypertension, insulin resistance, and type 2 diabetes mellitus in adult life. Several studies have confirmed and extended the Barker et al2 hypothesis to fetal programming of Parkinson’s disease, dementia, osteoporosis, and polycystic ovary syndrome.3 Although most clinical and experimental studies support the role for fetal programming of adult hypertension, there is still controversy regarding the cause and mechanisms underlying this phenomenon. Studies to date implicate reduced nephron endowment, factors that affect endothelial and arterial compliance, alterations in the function of renin-angiotensin system (RAS), and programming of the major organs and endocrine/neural systems involved in long-term blood pressure regulation.1 Despite intense investigation into the mechanisms underlying fetal programming of adult hypertension, there is still no unifying hypothesis on how these different mechanisms and pathways are programmed in utero and how they ultimately result in dysregulation of blood pressure later in life. It is well documented that premenopausal women exhibit a lower incidence of cardiovascular disease and hypertension compared with age-matched …

The Influence of Abnormal Sex Differences in Life Expectancy on National Happiness

Countries with better health, as indexed by life expectancy, score higher on subjective well-being (SWB). It was predicted that deviations from the average sex difference in life expectancy (reflecting reproductive competition among males and discrimination against females) would be inversely related to happiness. Regression analysis of SWB for 178 countries found that deviations from the average sex difference in life expectancy were predictive of unhappiness controlling for life expectancy, national wealth, and income inequality. Countries with a relative scarcity of female children (used as an index of parental bias) were less happy. Societies in which there is an undue burden on the health and survival of either sex are thus unhappy ones due to gender-specific disadvantage and associated gender conflict.

From Divergence to Convergence: The Sex Differential in Life Expectancy in Canada, 1971–2000*

Over the 20th century sex differences in life expectancy in the industrialized countries have widened in favour of women. Recently, a reversal in the long-term pattern of this differential has been noted in some countries. In Canada, between 1981 and 2000, this differential narrowed by almost two years. Greater than expected improvements in male death rates with respect to heart disease, lung cancer, accidents and violence (excluding suicide) explain a large part of this phenomenon. Change in male and female smoking prevalence correlates strongly with change in sex differences in mortality from heart disease and cancer. The reasons underlying men's greater mortality improvements in regard to accidents and violence are less clear and need further investigation.

Narrowing Sex Differential in Life Expectancy in Canada and Austria: Comparative Analysis

Throughout most of the 20 th century the sex gap in life expectancy in the industrialised countries widened in favour of women. By the early 1980s a reversal in the long-term pattern of this differential occurred in some countries, where it reached a maximum and thereafter has followed a declining trend. It is argued in this study that this development represents an emerging feature of the epidemiological profile of post-industrial societies. I look at Canada and Austria as two representative cases of this phenomenon over roughly three decades, between 1970 and 2001. Decomposition analysis shows that reduced sex differences in life expectancy in the 1980s and 1990s obtained mainly from the effects of reduced sex differences in mortality with respect to heart disease, and secondarily accidents and violence and lung cancer. Heart disease has played a larger role in Canada, whereas differential mortality from accidents and violence has been of greater importance in Austria. A further aspect of the investigation links sex differences in smoking prevalence to sex differences in life expectancy. A model is suggested that incorporates female labour force participation and a measure of gender role traditionalism in society as factors in female smoking prevalence. These variables are also postulated to correlate with change in the sex gap in life expectancy by a time lag of twenty years. It is found that sex differences in smoking prevalence in the past are related to sex difference in life expectancy in the present, and that female labour force participation and gender role traditionalism are also associated with the sex gap in expectation of life. The findings are interpreted in reference to epidemiological transition theory and the literature concerning change in the position of women and sex differences in mortality in high-income nations.

Social sexual inequality and sex difference in cancer incidence

Socioeconomic factors play many roles in influencing health including overall health status, lifestyle and occupational exposures, and access to preventive, diagnostic and treatment services. This paper reviews evidence on the geographical distribution of the sex differences in cancer incidence and life expectancy. The analyses reported are at the regional (Italy), continental (Europe), and world-wide scales. In agreement with other contributions on the social epidemiology of cancer, these results indicate that there is a close link between the health of the populations, and socioeconomic and cultural factors, and support the notion that environment contributes strongly to total cancer incidence. Thus, the emphasis for reducing cancer incidence needs to focus more on reducing environmental contributions. In order to improve the health status of the populations, not only applications of the present etiologic knowledge are necessary (for example, it is estimated that around up to 50% of cancers are nowadays technically preventable), but also further research on environmental topics should be stimulated. Within this perspective the indicators of health differences between genders—which are demonstrated to be very sensitive to socioeconomic and cultural factors—can play a very useful role for monitoring environmental factors, and for health planning by agencies and governments.

Frailty Index as a Measure of Biological Age in a Chinese Population

The concept of a frailty index, developed in Canadian elderly populations as an indicator of biological age as opposed to chronological age, was tested in an elderly Chinese population to determine whether it is applicable in a different ethnic and cultural setting. A data set including 62 physical, psychological, and socioeconomic variables from a cohort of 2,032 persons 70 years and older (999 men, 1,033 women) was used. The distribution of the index was evaluated using the Cramer-von Mises goodness-of-fit test, and multiple linear regression was used to assess its relationship with age and sex. A biological age for each participant was calculated based on an inverse regression of age on mean frailty index and sex. The Cox proportional hazards regression model was used to assess the ability of biological age to predict death. The distribution of the frailty index most closely resembled a Weibull distribution. The frailty index increased with age until the mid-80s, when it leveled off, and was higher in women than men for each age group. The distribution of biological age is wider than that for chronological age, and it strongly predicted death. Women had an estimated 20% lesser chance of dying at a given time than did men of the same chronological age and degree of frailty. The study confirms the robustness of the concept and method of calculating the frailty index developed in elderly Canadian populations. It also suggests that the sex difference in life expectancy may have an underlying genetic basis independent of frailty.

A VARIED PATTERN OF CHANGE OF THE SEX DIFFERENTIAL IN SURVIVAL IN THE G7 COUNTRIES

Over the course of the 20th century the sex differential in life expectancy at birth in the industrialized countries has widened considerably in favour of women. Starting in the early 1970s, the beginning of a reversal in the long-term pattern of this differential has been noted in some high-income countries. This study documents a sustained pattern of narrowing of this measure into the later part of the 1990s for six of the populations that comprise the G7 countries: Canada, France, Germany, Italy, England and Wales (as representative of the United Kingdom) and USA. For Japan, a persistence of widening sex differences in survival is noted. The sex differences in life expectancy are decomposed over roughly three decades (early 1970s to late 1990s) from the point of view of four major cause-of-death categories: circulatory diseases, cancers, accidents/violence/suicide, and 'other' (residual) causes. In the six countries where the sex gap has narrowed, this has resulted primarily from reduced sex differences in circulatory disease mortality, and secondarily from reduced differences in male and female death rates due to accidents, violence and suicide combined. In some of the countries sex differentials in cancer mortality have been converging lately, and this has also contributed to a narrowing of the difference in life expectancy. In Japan, males have been less successful in reducing their survival disadvantage in relation to Japanese women with regard to circulatory disease and cancer; and in the case of accidents/violence/suicide, male death rates increased during the 1990s. These trends explain the divergent pattern of the sex difference in life expectation in Japan as compared with the other G7 nations.

A divergent pattern of the sex difference in life expectancy: Sweden and Japan, early 1970s‐late 1990s

For most of the 20th century the sex gap in life expectancy in the industrialized countries has widened in favor of women. By the early 1980s a reversal in the long-term pattern of this differential had occurred in some countries, where it reached a maximum and thereafter followed a declining trend. Of particular interest to the present investigation is the anomalous experience of Japan, where unlike other high-income countries the female advantage in life expectancy has been expanding. We contrast the case of Japan with that of Sweden, where, like many other high-income nations, the sex differential in longevity has been narrowing in recent years. We observe that in Sweden, until the early 1980s, the sex gap in life expectancy (female-male) exceeded that of Japan; but this situation reversed in subsequent periods, when the Swedish differential narrowed and that of Japan widened. A decomposition analysis indicates that these divergent patterns since 1980 have resulted mainly from larger than expected reductions in male mortality in Sweden due to heart disease and from accidents and violence, lung cancer and "other" cancers. In Japan, death rates for men and women from heart disease--which is a leading cause of death--have tended to decline more or less at the same pace since the early 1980s; and with regard to lung cancer, and "other" neoplasms, male death rates in Japan have been rising while those of women have either declined or risen more slowly. Moreover, during the 1990s, male and female suicide rates rose in Japan, but the rates for men went up faster. Altogether, the net effect of these divergent mortality trends for men and women in Japan underlie much of the observed widening of its sex differential in longevity in recent years.

Inequalities in health: the value of sex-related indicators.

My laboratory has previously shown that the sex differences in tumor incidence in Europe can be related to the female social condition and that the pattern of this relationship varies according to the different historical contexts. In this article, I have extended the study worldwide to all cancer registries, and I present the sex differences in life expectancy at birth. A close link between the health of the populations and socioeconomic and cultural factors was confirmed. The sex-related indicators had a distribution independent from the parent variables cancer incidence and life expectancy; thus, they carry complementary information and provide an additional, sensitive probe for monitoring the health of the populations.

Narrowing sex differences in life expectancy: regional variations, 1971-1991

A number of industrialized nations have recently experienced some degrees of constriction in their long-standing sex differentials in life expectancy at birth. In this study we examine this phenomenon in the context of Canada’s regions between 1971 and 1991: Atlantic (Newfoundland, Nova Scotia, New Brunswick, Prince Edward Island); Quebec, Ontario, and the West (Manitoba, Saskatchewan, Alberta, British Columbia, Yukon and Northwest Territories). Decomposition analysis based on multiple decrement life tables is applied to address three questions: (1) Are there regional differentials in the degree of narrowing in the sex gap in life expectancy? (2) What is the relative contribution of major causes of death to observed sex differences in average length of life within and across regions? (3) How do the contributions of cause-of-death components vary across regions to either widen or narrow the sex gap in survival? It is shown that the magnitude of the sex gap is not uniform across the regions, though the differences are not large. The most important contributors to a narrowing of the sex gap in life expectancy are heart disease and external types of mortality (i.e., accidents, violence, and suicide), followed by lung cancer and other types of chronic conditions. In substantive terms these results indicate that over time men have been making sufficient gains in these causes of death as to narrow some of the gender gap in overall survival. Regions show similarity in these effects.

Contribution of cause-specific mortality to changing sex differences in life expectancy: seven nations case study.

During the last two decades some industrialized nations witnessed varying degrees of constriction in their sex gaps in overall life expectancy. We investigate this development by paying particular attention to the contributions of major causes of death to the change in the difference between 1970 and 1990. The analysis is based on the experiences of seven nations: Australia, United States, Sweden, England and Wales, Portugal, Hungary, and Japan. In the first four countries the gap has been narrowing during the last twenty years; in Hungary and Japan, the difference remains substantial and continues to expand; in Portugal the situation is characterized by a slowdown in the amount by which the sex gap is expanding over time. We apply decomposition analysis to answer the following questions: (1) What is the relative contribution of major causes of death to sex differences in average length of life within broad age categories? (2) How do the contributions of age and cause of death vary across time to either widen or narrow the sex gap in survival? (3) How do the patterns of cause contribution vary across societies?

Changing sex differences in life expectancy in Australia between 1970 and 1990

"In this study we decompose the gender based survival difference [in Australia] in 1970, 1980 and 1990 into components that can be attributed to different causes of death. Our analysis indicates that a significant component of the constriction in the differential was due to males having made larger gains than females over time with respect to heart disease, accidents and violence excluding suicide, and lung cancer.... We discuss [the] findings in the context of emerging epidemiological trends in the industrialized world, and the implications these have for the future of the sex differential in survival."

Smoking. The contribution of smoking to sex differences in life expectancy

Several studies have shown that smoking is a major cause of the lower life expectancy of men compared to women, but there has been no research to assess how far international differences in sex differences in life expectancy and changes in these differences can be accounted for by smoking. This paper gives quantitative estimates of the effects of smoking on sex differences in life expectancy at age 35 years in Denmark, Finland, Norway, Sweden and The Netherlands during 1970–1989. The data on cause-specific mortality by age and sex were obtained from standardized computer-tape transcripts of the WHO mortality data bank. An indirect method based on lung cancer mortality as the indicator of the cumulative effects of smoking was used to estimate the numbers of smoking-attributable deaths in 4 periods. The validity of the method was assessed by comparing the relevant parts of the results with those obtained in 8 national follow-up studies. On average, 2.4 years or more than 40% of the total sex difference in life expectancy in 1970–1974 was estimated to be attributable to smoking in the 5 countries. By 1985–1989 the contribution of smoking dropped to 1.8 years or approximately 30% of the total difference. The contribution of smoking to the sex difference was greatest in The Netherlands and smallest In Sweden. As a result of the decline in smoking-attributable male mortality, the sex difference in life expectancy diminished in Finland In the 1980s. In the other countries the difference continued to grow despite the increase in the loss of female life expectancy caused by smoking.

Narrowing sex differentials in life expectancy in the industrialized world: early 1970's to early 1990's.

Between the early 1970's and 1990's, twelve industrialized nations experienced for the first time a narrowing of their sex differences in life expectancy at age zero. In another set of countries, the differential has not yet reached a stage of convergence, although in some of these nations the female advantage appears to be increasing at a slower pace than ever before. We discuss the demographic and epidemiologic conditions for this new and largely unanticipated trend, as well as its applied and theoretical implications in the context of the following questions: (1) Is the observed change a function of males' faster pace of gains in life expectancy since the early 1970s? (2) What is the relationship between country differences in socioeconomic development (as measured by GNP) and the degree of convergence in the sex gap in average length of life? (3) What is the degree of association between temporal change in age-sex specific death rates and change in the sex gap in life expectancy over the twenty-year interval between the early 1970s and early 1990s? Our results indicate that where some convergence has taken place, in relation to women, men have experienced more rapid gains in survival; the higher a nation's level of social and economic development, the greater the amount of convergence in male and female life expectancies. The most pronounced age-specific association with the changing sex gap in longevity is that of ages 25-59, where the greater reductions in male mortality, as compared to that for females, contributed to a significant portion of the observed convergence in life expectancy across industrialized nations.

The Narrowing Sex Differential in Mortality in Canada Since 1971

In this study we confine our observations to Canada and evaluate three questions: (1) What causes of death have contributed to the narrowing of the sex difference in life expectancy between 1971 and 1991? (2) What is the relative contribution of different causes of death to the survival discrepancy within specified age categories? (3) How have cause-specific mortality differences between the sexes changed over time in their impacts on the differential in life expectation? In our discussion section we assess the relevance of our empirical results to the substantive issues underlying this investigation namely the importance of bio-demographic and sociological factors for the onset of reversal in the sex gap in death probabilities. (SUMMARY IN FRE) (EXCERPT)

Potential Reproductive Rates and the Operation of Sexual Selection

In most animals, members of one sex compete more intensely for mates than members of the other sex, and show a greater development of secondary sexual traits. The relative intensity of mating competition in the two sexes depends on the operational sex ratio (OSR) (the ratio of males that are ready to mate to females that are ready to mate) at the site and times when mating occurs. The extent and direction of biases in the OSR is closely related to the potential rates of reproduction that individual males and females can achieve, although the distribution of the two sexes in space and time, sex differences in development time or life expectancy, and biases in the sex ratio at birth or hatching can also be important. The potential rates of reproduction in the two sexes are, in turn, affected by the proportion of time and energy expended by male and female parents on their progeny, though other factors may constrain reproductive rate in one or both sexes. We outline a simple model of the factors affecting the OSR, where relative parental expenditure by the two sexes and the adult sex ratio are fixed, and a more complex model where the adult sex ratio varies in relation to the reproductive activity of the two sexes. This framework for relating sex differences in mating competition to the OSR, potential reproductive rates, and parental expenditure differs from Triver's concept of the relation between parental investment and mating competition in three ways: first, it identifies the OSR as the immediate factor determining which sex completes most intensely for mates; second, it recognizes that factors other than the future fitness costs of rearing offspring can affect the potential reproductive rate of the two sexes; third, it suggests an empirical measure (potential reproductive rate) that can be estimated in natural populations and used to predict the distribution of mating competition.

Why do men have higher expectancy than women?

The aim of the present study was to test the hypothesis that sex differences in expected academic achievement could be explained by corresponding differences in perceived intellectual ability, and to explore the relationship between perceived ability and the sex role related traits of instrumentality and expressiveness. Results showed sex differences both in expectancy and perceived ability. When perceived ability was controlled, sex no longer related to expectancy. A small correlation was found between expectancy and a measure of instrumentality. The latter variable correlated substantially with perceived ability. A measure of expressiveness was unrelated both to expectancy and perceived ability. Path analysis gave results consistent with the hypotheses that men have higher perceived ability than women because men think of themselves as more instrumental than women do, and that instrumentality determines expectancy indirectly through its relationship to perceived ability.

Sex differences in personality and expectancy

It has been shown that women have a lower expectancy than men before examinations, without there being any differences in past performance levels or in work spent in exam preparations. It was proposed that these sex differences in expectancy could be understood as an expression of differences in instrumental/expressive personality dispositions. In a group of undergraduate psychology students tested a short time before examination, scores on a composite index called “Strong” were found to account for a significant but small amount of variance in expectancy estimates. The relationship between expectancy and Strong was also found to depend on the level of another composite index called “Warm.” A fairly high correlation between expectancy and Strong was thus found for Ss describing themselves as warm. For Ss describing themselves as not very warm, no relationship between expectancy and Strong was found. When differences in personality traits were controlled, however, women were still found to have a lower expectancy than men. Expectancy was found to be a more accurate predictor of actual grades for Ss with high scores on instrumental traits than for Ss with low scores.

Ability Level, Evaluative Feedback, and Sex Differences in Performance Expectancy

This study represents an effort to clarify the effects of negative and positive information on performance expectancies of males and females. In testing the effects of feedback on 93 women and 97 men undergraduates, ability level, information condition, self-esteem level, and sex of subject were included in a 2 × 2 × 2 × 2 factorial design. Before feedback, males stated higher expectancies ( p < .05) and overestimated their performance more ( p < .05) than did females. Sex by feedback interactions ( p < .02) revealed that after feedback consistent with subjects' ability, males continued to set higher goals and to overestimate their performance more, but that after inconsistent feedback this sex difference did not occur.

Exploring sex differences in expectancy, attribution, and academic achievement

Two studies were carried out to explore if sex differences in expectancy and attribution of achievement are related to sex differences in academic performance. Study I investigated expectancy and attribution of achievement, operationalized as grade point index, among 176 male and 116 female college freshmen. Men were found to form higher expectations for future grades. Attributions measured through assigning percentage weights to ability, luck, effort, and difficulty as causal explanations of one's grade point index showed that men make more ability and women more effort attributions. Despite these differences in expectancy and attribution patterns, men and women were found not to differ in their performance. In Study II 120 college freshmen, half of them male, half female, filled out questionnaires before and after a midterm examination. A subsample of 49 also completed the Bem Sex Role Inventory. The results basically confirm the previous study's findings, except in Study II, men and women gave equally high weights to effort as a cause. The results also show that a feminine sex-role orientation is associated with a debilitating pattern of expectancy and attribution and lower performance, especially among women. Implications of the results for unraveling inconsistencies in the attribution literature and for a need to clarify connotations of femininity are discussed.