Showing papers in "Biodemography and Social Biology in 1982"
TL;DR: A higher incidence of mildly low birth weight in children born to schizophrenics is associated with developmental abnormalities at one year, and a large number of results which involve the schizophrenic fathers are reported.
Abstract: A twenty‐year study was begun in Denmark in 1962 of the differential effects of pregnancy and delivery complications on children of schizophrenic parents, on children of normal parents, and on children of parents with nonschizophrenic psychiatric disorders. This paper studies these children and their parents in 1971 utilizing data on pregnancy, delivery, and the physical and neurological examinations of the children at birth and at one year of age. Results include (1) a higher incidence of mildly low birth weight in children born to schizophrenics, also associated with developmental abnormalities at one year, (2) a higher incidence of infant females suffering from the effects of pregnancy complications, particularly where the schizophrenic parent was the father, and (3) a large number of results which involve the schizophrenic fathers.
174 citations
TL;DR: How nutrition can affect the time of attainment and level of function of each reproductive event in the female, thus affecting the length of reproductive span and reproductive efficiency, is discussed.
Abstract: A minimum weight for height, apparently representing a critical fat storage, must be maintained for the onset and maintenance of regular menstrual function in the human female. This paper discusses how nutrition can affect the time of attainment and level of function of each reproductive event in the female, thus affecting the length of reproductive span and reproductive efficiency. When the observed fertility rate of a population is lower than that in a well‐nourished noncontracepting population, the lower fertility could be explained wholly or in part by inadequate nutrition causing delayed menarche, longer than normal adolescent sterility, irregularity or cessation of menstrual function, higher pregnancy wastage, longer lactational amenorrhea, and early menopause.
40 citations
TL;DR: There is an association between genes of like effect and the resulting gametic phase (linkage) disequilibrium explains the large variance increase.
Abstract: Two classic papers on assortative mating, by Sewall Wright (1921) and R. A. Fisher (1918), are reviewed. Assortative mating causes an increase in homozygosity and in the population variance. However, with multiple factors the increase in homozygosity is very slight, while the increase in variance is large. There is an association between genes of like effect and the resulting gametic phase (linkage) disequilibrium explains the large variance increase. Formulas are given to include dominance and environmental effects for a trait determined by a large number of loci. The effect of assortative mating on the correlation between certain relatives is also given. These results were shown earlier by Fisher (1918), but are derived here by a more elementary method.
32 citations
TL;DR: In this paper, the degree of assortative mating with respect to physical characteristics varies by economic and social class within European national and ethnic groups and there is some tendency toward higher marital associations for physical characteristics among populations in the Mediterranean region than among those in Northern and Western Europe.
Abstract: This paper lists marital correlations for 105 physical characteristics in 40 human population samples. Correlation coefficients in the range + 0.1 to 0.2 are most frequently observed for measurements of body size in Europeans and Americans of European descent, although coefficients in the range +0.2 to 0.3 are commonly found. Homogamy coefficients above 0.5 are rare, at least in European peoples. The degree of assortative mating with respect to physical characteristics varies by economic and social class within European national and ethnic groups. There is some tendency toward higher marital associations for physical characteristics among populations in the Mediterranean region than among those in Northern and Western Europe. Studies of assortative mating in non‐European populations are few. The two populations sampled, Navaho Indians and Japanese, do not practice homogamy for body size.
28 citations
TL;DR: Theories of mate selection and the effects of assortative mating are reviewed in this paper, including differences in the basic theoretical orientations of the social and biological sciences with respect to human evolution and assortive mating.
Abstract: Theories of mate selection and the effects of assortative mating are reviewed, including differences in the basic theoretical orientations of the social and biological sciences with respect to human evolution and assortative mating. Topics discussed include evolution in parallel and interaction, terminology of nonrandom mate selection, theories of mate choice, social stratification and class endogamy, and suggestions for future research.
13 citations
TL;DR: The consequences of mutation and selection hypothesis are sufficiently distinct in some cases so as to contribute direct evidence for the existence of mutation for recessive autosomal diseases in man.
Abstract: Available data on inbreeding in India are divided into two geographical zones: the north, with comparatively little inbreeding, and peninsular India with very heavy inbreeding. The coefficient for autosomal inbreeding in Bombay varies from 0.001 to 0.013; in rural Andhra Pradesh, from 0.015 to 0.048. Available literature on genetic effects of inbreeding in human populations is reviewed. Formulas are given for calculating the decline in the frequency of deleterious genes under inbreeding over a period of generations. Under certain conditions, the decline in gene frequency is very marked. The consequences of mutation and selection hypothesis are sufficiently distinct in some cases so as to contribute direct evidence for the existence of mutation for recessive autosomal diseases in man.
8 citations
TL;DR: Data on inbreeding in several contemporary human populations are compared, showing the highest local rates of inbreeding to be in Brazil, Japan, India, and Israel.
Abstract: Data on inbreeding in several contemporary human populations are compared, showing the highest local rates of inbreeding to be in Brazil, Japan, India, and Israel. American populations are notewort...
6 citations
TL;DR: The author hypothesizes that the wide differences among populations in natural fertility may also be due to phsyiological differences relating to frequency and duration of anovulation during the suckling period.
Abstract: A study of natural fertility in diverse human populations shows marked differences in fertility among populations where birth control is either unknown or little practiced. Although differences appear among European populations, they are far more striking when European and non‐European populations are compared. On the whole, the former space births far less than the latter. Behavior differences in resumption of sexual relations after a birth do not seem to explain all of the variation. The author hypothesizes that the wide differences among populations in natural fertility may also be due to phsyiological differences relating to frequency and duration of anovulation during the suckling period.
3 citations
3 citations
2 citations
TL;DR: A study among college students of knowledge of, attitude toward, and potential use of techniques for predetermining the sex of children indicates that a sizeable percentage would take advantage of such techniques if available as discussed by the authors.
Abstract: A study among college students of knowledge of, attitude toward, and potential use of techniques for predetermining the sex of children indicates that a sizeable percentage would take advantage of such techniques if available. In this sample, 55.4 per cent would prefer a male first child, resulting in a sex ratio of 122 males for every 100 females if ideal family size were converted to actual family size. A strong relationship exists between desire for small family size and favorable attitude toward sex predetermination. The data suggest that the adoption of sex predetermination, even to a limited extent, would affect first‐child pattern, sex ratio, and the birth rate.
TL;DR: It is reported that the mean coital frequency of women taking the pill exceeds the average for women using all other contraceptive methods, but in time to conception there is no difference in the time required to conceive between women who had previously used the pill and those who had used other methods of contraception.
Abstract: Using data from two sample survey studies of fertility in the United States, the authors report that the mean coital frequency of women taking the pill exceeds the average for women using all other contraceptive methods. However, in time to conception, the data indicate that when all factors are taken into account there is no difference in the time required to conceive between women who had previously used the pill and those who had used other methods of contraception.
TL;DR: In the past, childlessness has been more common among non-whites than among whites, but since the 1940's, the incidence of all kinds of childlessness had declined sharply.
Abstract: In the past, childlessness has been more common among nonwhites than among whites. Since the 1940's, the incidence of all kinds of childlessness has declined sharply. However, the decline in childl...
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TL;DR: Results show that fetal loss in matings of the parental generation increases cumulatively by some 2.5% to 3% with each additional country of birth in the great‐grandparental generation, and that with increased mixture of these gene pools, fetal loss increases proportionately.
Abstract: While a rapid increase in mating between ethnic groups has been noted in the United States in the past twenty years, few studies have been made on the consequences of out‐crossing. This report conveys findings on the interrelationships of three factors: fetal loss, number of countries in the background of parents, and the distances between birthplaces of parents. Data show that fetal loss in matings of the parental generation increases cumulatively by some 2.5% to 3% with each additional country of birth in the great‐grandparental generation. Increased fetal loss is also related to greater distances between birthplaces of mates within the parental generation. Low fetal loss is found with a small number of countries in the background and shorter distance between birthplaces. It is suggested that a larger number of countries of birth represents a larger number of Mendelian gene pools and that with increased mixture of these gene pools, fetal loss increases proportionately. An animal model is cited ...
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TL;DR: Three populations of Cayapo Indians from southern Para and northern Mato Grosso, Brazil, show similar age distributions and endogamy rates, but low sex ratios and inbreeding rates, in comparison to those of other South American hunters and gatherers with incipient agriculture as discussed by the authors.
Abstract: Three populations of Cayapo Indians from southern Para and northern Mato Grosso, Brazil, show similar age distributions and endogamy rates, but low sex ratios and inbreeding rates, in comparison to those of other South American hunters and gatherers with incipient agriculture. Their fertility is moderate with a small variance, and mortality is low. The index of opportunity for selection is one of the lowest calculated so far for groups at this cultural stage. The pattern of exchange between the local groups can be described by the fission‐fusion model of genetic structure.