Suchergebnisse

An analysis of the nature of feedback mechanisms which operate between physical & cultural evolution. It is indicated that the rate of cultural evolution in modern human pop's is substantially controlled by non-genetic factors, ie, by soc enviromental & geographic opportunities. In the same vein, diff's in technological levels are explicable re diff'ial opportunity rather than by diff'ial intelligence. In various historical phases, a species depends on diff types of feedbacks as sources of energy for eveolutionary change, M. Farber.

The argument between racial 'typologists' & 'populationists' is clouded by misunderstandings which make the viewpoints more irreconcilable than they really are. The theoretical bases of both stands are sketched. The possibility that there is some validity in Czekanowski's typology, & his concept of racial types, is examined. D. Cooperman.

A discussion of the raciation process, ie, a& 'branching evolution at the sub-species level, for which reproductive isolation between 2 or more parts of a breeding pop is both a necessary & sufficient condition. The extent of racial divergence hinges on the rate & direction of evolution of the given isolates. Among humans, the process is modified by culture. Thus, gene-flow barriers may be produced by ethnic or soc diff's as well as by geographic isolation or isolation by distance. D. Cooperman.

The strength of influence upon statural variation of: (1) the degree of urbanization of the locality of habitat, (2) family size, (3) paternal and (4) maternal educational status was analysed in three generations of 19-year-old Polish conscripts, examined in 1965, 1986 and 1995. Each of the above factors of an individual's social situation was described by a 4-level scale. Each factor was found to exert a highly significant residual effect on stature throughout the three decades considered, even after the effects of other correlated factors were partialled out by three-factor ANOVA. However, the stratifying force of each factor, as expressed by the dispersal of the level-specific main effects around the national mean, has been changing over time. For example, the growth-stunting effect of the condition of coming from a large sibship was dramatic in the 1965 cohort and considerably attenuated in 1986 but ceased to diminish thereafter. The growth-enhancing effect of the condition of being a large-city dweller, initially marked, has almost disappeared; but the growth-stunting effect of the condition of being a rural dweller has remained equally strong across all cohorts. These and other shifts in the relative importance of the social factors, as presumed determinants of family living standards, are described and some explanations attempted.

The incidence of obesity, defined as the fraction of persons with BMIs exceeding 30·0, was examined in two birth cohorts of 40–50-year-old occupationally active inhabitants of the city of Wrocław, Poland. In both cohorts and both genders obesity increased monotonically with decreasing position on a three-level educational scale. During the 1986–1996 decade obesity increased dramatically among males with trade school education only; concomitant shifts were much smaller or absent in the college-educated groups. The contrast in obesity between the opposite ends of the educational scale has widened markedly in both genders; and the between-gender gap has declined somewhat.

SummaryIn this study it is hypothesized that taller individuals are more likely to move up the scale of educational attainment compared with shorter individuals from the same social background. Three national cohorts of 19-year-old males were considered: 29,464 born in 1967 and surveyed in 1986, 31,062 born in 1976 and surveyed in 1995, and 30,851 born in 1982 and surveyed in 2001. Four social variables were used to describe the social background of each conscript in the three surveys: degree of urbanization, family size, and parental and maternal educational status. The educational status of each conscript was classified into two groups: (1) those who were secondary school students or graduates, or who had entered college, and (2) those who had completed their education at the primary school level or who had gone to a basic trade school. Multiple binomial logistic regressions were used to estimate the relative risk of achieving higher educational status by 19-year-old males relative to height and the four social factors. Consistently across the three cohorts the odd ratios (ORs) indicate that height exerts an independent and significant effect on the attained level of education at the age of 19 years in males (1986: OR=1·24, p<0·001; 1995: OR=1·24, p<0·001; 2001: OR=1·20, p<0·001). Two possible, not mutually exclusive, selective mechanisms are postulated and discussed: 'passive' and 'active' action.

SummaryIn modern societies, there are regular social gradients in most health parameters, and also in the structure of morbidity and mortality. However, the significance of inter-generation social mobility for general health status still remains equivocal. This study was therefore performed in order to compare the effect of social mobility on coronary heart disease (CHD) risk between middle-aged Polish men and women. A total of 342 men and 458 women, aged 40 and 50 and inhabitants of Wrocław, were examined. Risk of CHD was estimated using the Framingham Risk Score (FRS), calculated for each individual. Social mobility was defined as an inter-generation change in social status expressed as educational level between the examined individual and his/her father. Using two-variable regression models, it was demonstrated that FRS in men was determined by both their father's education level (β=0·33, p<0·0001) and inter-generation change in educational status (β=0·18, p=0·008). In contrast, FRS in women was related only to their father's education level (β=0·35, p<0·0001), but not to inter-generation social mobility (β=0·35, p=0·25). In particular, an incremental change in educational level among those men whose father had finished primary school at the very most or among those whose father had finished basic trade school was accompanied by a significant decrease in FRS (F=4·12, p=0·009 and F=3·25, p=0·04, respectively). It is concluded that inter-generation social mobility modifies CHD risk (as estimated using FRS) in middle-aged Polish men, but not in women. The precise mechanisms responsible for the observed sex difference in this phenomenon need to be established in further studies.