The incidence of family breakdown and stress has been examined in an unselected group of 92 South Wales families, each containing a patient suffering from Huntington's chorea, and related to the onset and duration of the disease, age of the patient, and behavioural symptoms shown. The frequency of actual and attempted suicide is analysed and the effects of the disorder on the primary care agent for the patient discussed. Some of the effects on children and the needs of the families for support and practical help are outlined. It is concluded that family support is an essential factor in any programme aimed at the long-term alleviation and prevention of Huntington's chorea.

This article discusses the conflicting positions on the effectiveness of sex education and availability of birth control facilities in lowering the rate of teenage pregnancies. It provides evidence of a drop in the rate of teenage births only one-third of which can be accounted for by the rise in abortions. It concludes that teenagers must have been using birth control more effectively than in the early 1970s.

In a sample of women presenting for postcoital contraception in central London, two main categories of women were apparent. The first comprised those having regular intercourse: the majority of these had experienced a contraceptive method failure. Many of the second category had used no contraceptive; they were often having intercourse for the first or second time with a new partner, for the first time after an interval with an existing partner or for the first time ever. Many women had experienced difficulty in finding out where they could be treated but were persistent in their efforts to obtain the necessary expert advice. Almost all had used contraception in the past. Acceptance of a contraceptive method for future use was high.

This paper reports on a study of decision-making among voluntarily childless couples that was conducted in Britain. The discussion is based on evidence from an intensive interview survey with 38 childless husbands and wives. Four main orientations towards childlessness have been delineated, hedonistic, idealistic, emotional and practical. These are based on the decision-making processes childless couples go through. Each orientation is described, showing that childless individuals can differ markedly in their attitude towards not having children and in their values and ideas about life in general. It is maintained that these differences are important in understanding the complexities of voluntary childlessness and can have practical value in studying aspects of the phenomenon, such as forecasting changes in the pattern of childlessness.

Medical students and members of infertile couples were questioned about their knowledge and attitudes toward artificial insemination using donor semen (AID). While both groups were well-informed about AID, considerable attitudinal diversity existed. Subjects generally favoured AID for infertile couples, for single women and for situations where the risk of inheritable retardation or genetic disease existed. Members of infertile couples were more positive about AID than were medical students, and females were more positive than males. The results indicate continued controversy regarding several aspects of AID such as whether to permit AID recipients to select their own donor and whether children conceived through AID should be so informed. The implications for infertility counselling are discussed.

Using daily report data from 85 husbands and wives for about 100 days each, this paper explores differences in sexual behaviour between menstrual and non-menstrual days. Intercourse and orgasm are reduced during menstruation, in association with impressively less female desire for intercourse during menstruation. In the highly educated group studied, the women respond to a resultant potential increase in male sexual frustration by providing the husbands an increase in non-coital orgasm on menstrual days.

This paper analyses the influence of maternal factors (mother's age, parity, prior birth interval, and subsequent birth interval) on mortality risk for 2150 Bangladeshi infants and children, taking the sex and age of the child into account. Logistic regression estimates from retrospective maternal birth histories for the period 1966–75 reveal age and sex patterns consistent with previous research. These estimates also demonstrate that there are associations with mother's age and parity, but that prior birth interval emerges as the strongest predictor of mortality risk. It appears that part of the mortality risk of mother's age and parity actually stems from association with shorter prior birth interval, a factor to which infant and child health programmes need to give more attention.

The patterns of male social mobility among the contemporary populations of Otmoor are described in terms of both intra- and inter-generational mobility. The social classes are differentiated by IQ and it is shown that sons' IQ is more highly correlated with their class, after their social mobility than before it. In 85 father-son pairs the number of steps sons moved in the social scale is positively related to the magnitude of the difference between their IQ and that of their fathers. However, the relationship between social mobility and IQ appears to be entirely confined to non-locally born subjects and the social mobility among the locals, although of comparable dimension is essentially non-meritocratic. These findings are discussed in relation to the structure of the Otmoor populations and particularly the phenomenon of selective out-migration.

Average heterozygosities for four communities (Savoonga and Gambell on St Lawrence Island, the King Island community now located in Nome, and Wales) are computed from blood allele frequencies. No significant relationship is found between this measure of heterozygosity and the amount of European admixture calculated from gamma globulin haplotype frequencies, indicating that forces other than European gene flow are affecting relative heterozygosity. However, within the two villages on St Lawrence Island, admixed individuals as a group have significantly higher average heterozygosity than non-admixed individuals. These results suggest that European gene flow significantly increases population heterozygosity when examined from a micro-populational or individual level, but may be obscured by other factors when several different populations are compared. This is probably because inter-village variation in admixture proportions, which range from zero to 8%, is small.

Comparison of single women who were initial and repeat abortion seekers revealed that the latter tended to perceive themselves as having a better knowledge of contraception, and to be more regular users of contraceptives. Repeat abortion seekers had more favourable attitudes towards abortion, and were more likely than first-time aborters to have initiated the abortion decision. Initial abortion seekers were somewhat more likely to rate their decision as most difficult. Both groups of single women mentioned similar reasons for wanting an abortion, although initial aborters mentioned somewhat more often the effect of the pregnancy upon career or studies, being unmarried, and disgracing their parents.

This paper describes the fertility, mortality, and marriage patterns of the Hungarian Settlement, Louisiana, USA, immigrant ethnic population and relates these demographic processes to the evolutionary forces of natural selection, genetic drift, and gene flow. The results indicate that the maximum opportunity for natural selection decreased over time, and natural selection could have operated in the case of this population at only a very moderate level. The demographic characteristics of this population suggest that genetic drift may be important as an agent of microdifferentiation. Gene flow, however, appears to be the most important evolutionary force in this population. The process, based on the increasing incorporation of non-Hungarians into the gene pool, is causing the breakdown of this ethnic/genetic isolate.

The population structure of the Toto tribe at Totopara, a small village in West Bengal, District Jalpaiguri, was studied, for since 1951 the Totos have been coming more and more in contact with the outside world and undergoing a process of cultural and developmental change. Demographic data presented include the age-sex structure, marital status, fertility, birth rate, death rate and population growth trends in the pre-contact and contact era. At present the population shows a trend towards increase.