This study explores the reasons which individuals give for initially wanting children; data are drawn from intensive interviews concerned with reproduction, marriage and family life which were conducted with couples in the childbearing stage of marriage. The study is an extension of the approach but forward by Busfield (1974) in that it examines the beliefs which structure social constructions of reproduction.

The evidence suggests that, although wide-ranging beliefs are drawn upon in accounting for wanting children, the underlying reasons are concerned with beliefs about the nature of ordinary adult life. However, except at a very general level, such beliefs are not uniformly held but are selected and structured by the particular situation and experience of individuals. The approach demonstrates how a deeper understanding of reproductive behaviour can be gained by relating it to the wider context of family, marriage and adult life.

The paper presents the results of five polymorphic systems in a sample of 999 individuals from Nottinghamshire. The results are classified by the socio-economic grouping of parents and self.

The results show that social class differences for the genetic attributes exist and are almost linear when aggregated distances are computed. There are differences, however, between parental and offspring results. These differences may be the result of changes in social class over the last generation. This social mobility is investigated and it is shown that an upward movement in social class is associated with characteristic genotype groupings.

An experiment was designed to test the effect of a synthetic hypothetical human female pheromone on sexual behaviour. Sixty-two married couples participated for 3 menstrual months. No effect was found.

This paper evaluates a Singapore experiment to test the Shettles ‘rhythm and douche’ method of sex control. The clinic was set up in the hope that if couples could have the son they desired, they would keep their families small in accordance with the goverment's strong commitment to population control. From March 1975 to July 1977, 10,000 newly-wed women were invited to attend the clinic. A thousand women, not all newlyweds, attended at least once. Of the 31 women who had definite sex preferences, who attempted to follow the method, and who gave birth between March 1975 and November 1977, all wanted boys. By chance alone, one would expect about sixteen to have boys. In fact, fourteen had boys. Only six of the 31 women reported using the method completely correctly.

Women attending the clinic at least once were more likely to have an outside job, to have a husband with a professional or managerial job, and to be of Chinese origin compared with the Singapore population. Clients coming either had fertility problems and had no sex preferences or wanted a boy. Of those coming at least once, 70% had no previous children; the rest had had 403 girls and 58 boys.

To test this sex control technique adequately, one would need a large sample of highly committed couples who are given intensive counselling and follow-up. This particular method appears to be impractical on a mass basis, apart from questions about its effectiveness. Other sex control methods currently under research may prove more practical and effective. A better solution would be to discourage boy preference and improve the opportunities for girls.

The influence of parental age at birth, and parity, was studied in a series of 48 dyslexic boys. It was concluded that both increased paternal and maternal age contributes to a greater incidence of the condition. The similarity to the age distributions of chromosomal aberrations and some mutation defects suggests some genetic implication. The findings thus favour a biological rather than environmental element in the aetiology.

Mortality from peptic ulcer among middle-aged Canadian males in the period 1959–63 has been analysed by marital status and social class. Adjustment for social class reduced only slightly the mortality disadvantage of single males compared with married males.

Sensory stimuli from the external environment (e.g. visual and olfactory stimuli, stress) or internal stimuli cause brain nerve fibres to release neurotransmitters (catecholamines, indolamines and cholinergic agents). These neurotransmitters regulate the secretion of gonadotrophin-releasing hormone (GnRH) from neurosecretory cells of the hypothalamus (Kamberi, 1975). It would seem that under the proper steroid environment, catecholamines (dopamine, norepinephrine or epinephrine) and the cholinergic agent acetylcholine exert a stimulatory influence, whereas indolamines (serotonin or its metabolic product, melatonin) have an opposite effect. In turn, GnRH reaches the anterior pituitary via the hypophyseal portal system, and, through the mediation of cAMP [though may be not as an obligatory intermediate (Naor et al., 1975)], controls gonadotrophin secretion (Labrie et al., 1974).

The use of the diaphragm and other vaginal caps has declined in the last decade with the rise of oral contraceptives and intrauterine devices. This is particularly clearly shown in the group of women attending family planning clinics. These changes have been accompanied by a shift in predominance from male methods to those initiated and managed by women.

Various characteristics of diaphragm acceptors at the King's group of hospital clinics have been studied from January 1972 to May 1976 and compared with those of women accepting other methods such as the pill and intrauterine device. There are marked differences in age at first attendance, and at various stages of family building; there are also differences in marital status and whether working outside the home or not. In the group of housewives accepting the diaphragm, there is an increased proportion whose partners are in non-manual occupations.

These differences are discussed in relation to the acceptability of vaginal barriers, the duration of their use and their effectiveness in the long term. If immediate acceptability could be improved by a new design, they might play a more useful part as a women's method of fertility control.

This study examines the relationship between verbal, performance and total IQ scores and social class of 193 male householders living in a Cambridge suburb. The correlation coefficients between IQ scores and present occupational status were significantly higher than the correlations between IQ scores and social class of origin, suggesting that intragenerational social mobility is positively related to IQ.

Parent–offspring data were available for 85 father–son pairs. Analysis of the IQ differences between fathers and sons in relation to their social class differences provided further evidence for selective migration related to both IQ components and total IQ scores. In this sample there was a simple relationship between the extent of social mobility and the degree of difference between the father's and son's IQ scores.

Interviews with 103 middle-class wives on their family building experiences and use of birth control techniques show this highly educated group to be effective family planners in comparison with other social groups. The wives developed clear ideas early in marriage about family size, timing and spacing, formulated with reference to sets of beliefs about the transmission of cultural advantage from parents to children, and their social responsibility in relation to world population levels. Ideas about the spacing of children and desired family size appear to be influenced by the women’s orientation towards returning to employment, but their relatively late age of terminating full-time education has had remarkably little effect on the timing of either marriage or the first child’s birth. Female contraceptive methods were most popular with this sample, and their relative effectiveness as family planners may be explained by their preference for the more reliable techniques and high level of motivation to use them efficiently. Variations in patterns of contraceptive usage noted between this and other studies are probably a function of age differences in the groups of women surveyed.

Urinary oestrogen and pregnanediol values were measured in 24 boys and 38 girls between the ages of 2 and 13 years. Longitudinal studies were conducted on eight girls, two of whom collected for periods of 4 and 5 years which included menarche and in one case establishment of ovulation. Highly sensitive assay methods were developed for measuring the very small amounts of oestrone, oestradiol and oestriol and pregnanediol present in the urine of young children. The total oestrogen values were within the submicrogram range of 0·1–0·5 μg/24 hr in the children aged 2–8 years, with no differences seen between the boys and girls. After the age of 8 years, oestrogen values above 1 μg/24 hr began to be encountered and by age 11½ years the majority of subjects were recording oestrogen values above this figure. The rise in the oestrogen values was more rapid in the girls than in the boys. Evidence was presented that a value of approximately 1 μg/24 hr represents the minimum oestrogen production for the initiation of breast development. The oestrogen values were fluctuating with irregular periodicities at all ages and the gradual general rises seen after the age of 8 years could be arrested at any stage for a year or more. Menarche was preceded by marked periodic fluctuations in oestrogen output which peaked above 15 μg/24 hr. In all subjects studied, the initial bleeding cycles were anovulatory as judged by the low pregnanediol values, the usual pattern being one of fluctuating oestrogen production. One subject was studied fully through to the establishment of ovulation, which first occurred 12 months after menarche. The approach of ovulation was indicated by pre-menstrual rises in pregnanediol which increased in amplitude from 0·4 mg/24 hr until finally 2 mg/24 hr was exceeded (the value accepted for ovulation). Evidence was presented that the interval from menarche to ovulation in different individuals was very variable, extending from ovulation at menarche itself to periods of more than a year. Recording of self-observed symptoms of production of cervical mucus could be of considerable value in documenting these events in larger populations.

A probabilistic model of the human reproductive process is used to assess the success of hypotheses designed to explain human sex ratio fluctuations. It is shown that theories based on different maturation rates or effective lifetimes of X- and Y-bearing spermatozoa cannot account for many of the major sex ratio fluctuations.

A specific physiological model is proposed, based on differential motility of the two types of spermatozoa in the female reproductive tract, which together with differential fetal mortality, accounts successfully for most of the ratio fluctuations. On this theory the principal factor determining sex ratio is the physiological state of the female reproductive tract which in turn is governed by complex physiological and psychological parameters.

Some retrospective data collected in a survey carried out in 1967–68 show that the practice of breast-feeding declined markedly in Great Britain between the 1930s and the 1960s. Throughout, women higher up the social-educational scale breast-fed more than those lower down. Women marrying before the age of 20 (as well as those marrying at age 30 or older) tended to breast-feed less than those marrying in their twenties; for the former, the explanation was probably ‘social’. Needing, or choosing, to return to work soon after confinement was not, in general, an important inhibiting factor so far as breast-feeding was concerned. From the 1967–68 data, there seemed to be a negative association between the level of breast-feeding and birth order, but this may not have been ‘genuine’ since other data did not agree. There was a positive association between level of breast-feeding and family size, for family sizes up to four, but a drop for those with five or more children. This latter feature could be the result of a tendency for those with large families to arrive at this situation by way of short interbirth intervals, this in turn being associated with low levels of breast-feeding; the former might possibly reflect a positive link between women' capacity to breast-feed and their capacity to bear children.

This report describes a family planning KAP survey conducted in 2000 households in rural Ghana between April and October, 1972, as one of the Danfa Project’s baseline studies. Subsequent re-surveys were done in 1975 and 1977 to assess changes related to project health education and family planning programmes.

Reported knowledge about family planning was three times that reported in previous studies in rural Ghana. About 70% of the respondents approve of family planning, but most want a large family, with over six children. At all ages, males wanted two or three more children than did women.

The current 3% population growth rate in Ghana may increase due to continued early age of marriage, the rising size of the reproductive age group and improved pregnancy outcome.

Although the expected relationships between knowledge and use of family planning and age and education were present, these differentials were typically only 10–15%. In the project area it appears that women will be most important in making the decision to practise family planning, although motivation of males is being stressed.

Most villagers hear about family planning through informal, word-of-mouth channels with relatively little use of news media, family planning workers or clinic health personnel. To improve the practice of family planning, village-based health educators are working with volunteers including traditional birth attendants, community leaders, teachers and church groups.

The sex composition of 862 sets of Australian triplets was independent of decade and State of birth during the period 1920–69. The triplet rate increased by 40% during the 50 years in contrast with declining rates reported elsewhere. The increase was due to dizygotic and trizygotic types, together but not individually, and occurred despite an 8·6% decrease in the average national maternal age over the same period. Adjustment for age led to standardized individual zygosity rates, estimates of which were compared with reported values obtained elsewhere. The dependence of zygosity rates on maternal age was shown to rise progressively as the number of ova released in triplet formation increases.

There have been substantial changes in the pattern of pregnancies to teenagers in England and Wales in the past 25 years. The number of births and abortions to teenagers has increased until the last 2–3 years since when there has been a decline. This paper looks at the changes that have occurred in the population structure and marital patterns of teenagers during these years, and examines teenage pregnancies and their outcomes with regard to some of the medical and social factors that may have influenced these changes.

Two samples of male students (N = 25, and N = 51) and a small sample of female students (N = 7) were administered the Sensation Seeking Scale (SSS), and blood samples were drawn on two occasions to determine plasma levels of androgens and oestrogens. Reliable and significant simple and partial correlations were found between the sex hormones and the SSS subscale, Disinhibition. Partial correlations simultaneously controlled for height, weight, age, and recency of orgasm.

At the end of the 4th week of the Hilary Term 1977, 1006 male and 1009 female undergraduates at Oxford University were sent a questionnaire enquiring about their sexual behaviour and contraceptive practice. Of the 862 women and 634 men who replied, 512 women (59%) and 332 men (52%) had experienced sexual intercourse, 396 women and 191 men in the 4-week period preceding receipt of the questionnaire. No contraception had been used by 27% of the women on the first occasion that they had had intercourse; during the 4-week period preceding receipt of the questionnaire 10% of sexually active women had had intercourse on one or more occasions without using a contraceptive. The use of contraception increased with the frequency of intercourse and the stability of the relationship. Thirty-one women had been pregnant in the past; none was known to be pregnant at the time of the survey, although sixteen suspected that they might be. Ninety per cent of the students approved of the free distribution of a booklet on contraception and related matters to all undergraduates.