Multivariate (correspondence) analysis is employed to identify socioeconomic factors affecting fertility and infant mortality in Marrakesh (Morocco), using questionnaire data from some 3000 women attending 20 dispensaries in different parts of the city. Factors of the material environment (availability of water and electricity in the residence), size of household and number of wage earners in it are pervasive and suggest a polarity between archaic elements in the society (low material comfort, polygyny, absence of contraception) and the more forward looking (monogamy, tertiary occupations). Fertility and child mortality variations reflect this polarity. The differences that occur among the 20 dispensaries direct attention to the neighbourhoods where public health measures may be expected to be most effective and rewarding.

Maternity histories from residents of a Pacific Island society, Tokelau, and migrants to New Zealand, are analysed using life table techniques. Inter-cohort differentials in patterns of family formation were found in the total Tokelau-origin population. The process of accelerated timing and spacing of pregnancies was more pronounced among migrants who tended to marry later, be pregnant at marriage, have shorter inter-pregnancy intervals at lower parities and to show evidence of family limitation occurring at higher parities. These results point to the significance of changing patterns of social control on strategies of family building.

In relation to two measures of the mobility involved in the migration histories of individuals now resident in the Otmoor villages of Oxfordshire, selectivity for components of the Wechsler Adult Intelligence Scale is clearly demonstrated. However, this selectivity is reconsidered in the light of other covariates of mobility, where these also relate to IQ, for example, some measures of temporal and socioeconomic variation. When correction is made for these, the frequency of highly significant correlations is greatly reduced, suggesting that much of the selectivity operates within the associations between mobility, IQ, and the confounding temporal and socioeconomic variables. There remains, even after removal of the effects of age, class and occupation-type, a pattern of significant association between some components of verbal IQ and the measures of mobility.

Using routinely collected data for 184,000 Scottish singleton live births in 1980–82, nine maternal factors were related to changes in the distribution of birthweight for given gestational age. Maternal height and marital status were associated with overall shifts in the distribution. In contrast, social class, a previous perinatal death or two or more previous spontaneous abortions in multiparae were primarily associated with increased risk of a small-for-gestational-age infant. A history of caesarean section or three or more previous live births was associated with increased risk of a large-for-gestational-age infant. The results of this population study were generally consistent with reported hospital-based findings.

A representative sample of over one thousand couples who married during 1979 in England and Wales was followed from the date of marriage until mid-1984 to investigate the characteristics of couples who divorce soon after marriage.

Couples who apparently lived together before marriage had a below average chance of early divorce, whereas couples where the addresses of the partners before marriage were very close had a significantly high rate of early breakdown. The chance of early divorce was significantly above average for spouses marrying in their teens and for both husbands and wives who, at their marriage, belonged to social class V. Couples who married with a civil ceremony had an above average (and those marrying with a religious ceremony a below average) risk of early divorce, but such differences were found to be negligible on analysing the results from a matched case-control study in which each ‘case’ marriage (one which ended in early divorce) was matched with a ‘control’ marriage (one which did not end in early divorce). Age at marriage, marital status before marriage and the social class of both partners, the factors controlled for in the case-control study, are likely to be amongst the strongest predictors of early divorce.

Data collected on fertility, mortality and family planning in two surveys in Papua New Guinea are presented. The first survey was conducted in rural and urban areas between November 1979 and March 1980 in eight provinces of Papua New Guinea, and the second between late June and early July 1981 in the Lae urban area. The unadjusted total fertility rates suggest that fertility is lower in the Lae urban area than in the rural and provincial urban areas. However, the adjusted rates indicate that fertility is higher in the provincial urban areas than in the rural and Lae urban areas. The results also confirm a trend towards lower infant and child mortality over the past 15 years, as well as the existence of moderate differentials between rural, provincial urban and the Lae urban areas.

Libya is one of the Middle East nations with very high fertility, and data from 1973 suggest the presence of a natural fertility regime marked by the absence of fertility limitation within marriage. Analysis of paternity data by occupation, however, identifies major differences in the level and pattern of childbearing. The Libyan data are compared with fertility and paternity data from an American frontier population to demonstrate that the general patterns observed are consistent with other natural fertility populations, while selected occupational groups may limit family size.

Examination of 150 husband–wife pairs from the Otmoor villages of Oxfordshire for levels of similarity in their performance of seven subtests of the WAIS IQ test showed significant positive correlation in five subtests but not in digit span or digit symbol. In no test was there any relation between level of spouse similarity and length of marriage. Scores were varyingly associated with several factors known to be related to total IQ, such as social class and nature of education. When the effects of these factors on IQ variation were removed statistically most of the spouse similarity disappeared. However there remained a significant residual similarity in vocabulary performance and some suggestion of one in similarities and block design.

Many physiological functions of the human body as well as human behaviour are regulated by endogenous rhythms. While circadian rhythms with periods of about 24 hr serve to adjust body functions and patterns of behaviour to the geophysical day/night cycle, intrinsic rhythms with shorter periods, called ultradian cycles, subdivide the 24-hr interval. For example, motor activity, perception and cognitive style are influenced by an intrinsic cycle of about 1½ hr. Despite numerous laboratory studies, the functions of ultradian rhythms are as yet unknown. In this field study, endogenous short-term cycles were observed in the daily behavioural patterns of illiterate individuals living without artificial time-cues in a small East Indian village community. Time series analysis of the result provides additional evidence that behavioural patterns of adults as well as infants and children living under natural conditions may be regulated by intrinsic rhythms with period intervals of 1–3 hr. Furthermore ultradian behaviour cycles in single subjects can be synchronized within a common time-frame. This suggests that intrinsic ultradian cycles may serve to organize daily behaviour patterns for optimal co-ordination and satisfaction of individual and common demands.

The influence of household type on reproductive behaviour is examined for a national probability sample of Taiwanese women. In spite of remarkable social and economic development over the past three decades, extended families are still widely found in Taiwan. Women in extended households have only slightly higher fertility preferences and current fertility than women in nuclear families once marital duration is controlled. Although women in extended households marry earlier and receive more family help with child care than women in nuclear households, such factors are no longer sufficient to produce major differentials in reproductive behaviour. The findings suggest that preferences for smaller families and low fertility need not await a transformation to a nuclear family structure.

Fertility in Peninsular Malaysia has declined continuously from the late 1950s, reaching a TFR of 3735 in 1983. All ethnic groups in Malaysia have contributed to this modern demographic transition but the rate of change has been most rapid for Chinese and Indians, Malay fertility having reached a plateau in the early 1980s. The effect of age structure, marital patterns and marital fertility (by parity) on the fertility declines for each ethnic community are analysed. Continuation of current trends would lead to replacement-level fertility for Malaysian Chinese and Indians by the year 2000. Malay fertility is likely to continue to decline but at a more moderate pace.

Sex ratio at birth was studied in relation to grandparental age, to enquire into the effect of the accumulation of X-linked recessive lethal mutations. From the data of the tenth census of the Italian population two samples of women having a live-born only child were examined: the first from some provinces of northern and central Italy, the second from the island of Sardinia.

Besides maternal grandfather's and grandmother's ages, the mother's age and some socioeconomic factors such as the woman's educational level, her urbanization index and time were included in a multiple regression analysis model. In both areas the results show a significant decrease of the sex ratio as grandpaternal age increases, a weaker effect of grandmaternal age, and a strong decrease when maternal age increases; this last effect is probably due to physiological factors, in addition to the genetic ones.

Differences between the partial regression coefficients of the two areas, though not significant, reflect the different socioeconomic and cultural conditions, which affect the sex ratio. From the partial regression coefficients on the grandpaternal age an estimate of the mutation rate was obtained.

This paper discusses polygynous marriages in rural Bangladesh, using marital status and birth registration data from the Demographic Surveillance System of the International Centre for Diarrhoeal Disease Research, for the period 1975–79. Of all the marriages recorded during this period about 5% were polygynous. To identify the women polygynously married, 1974 census data of the DSS area were used. The difference in age at marriage between the polygynous groom and his subsequent wife was 15 years on average. The socioeconomic indicators studied were education, occupation and area of dwelling space. In general, these indicators differentially influence polygynous marriage. The fertility differentials between women in monogamous marriages were significantly higher than between the women in polygynous unions.

Analysis of data from the Guyana Fertility Survey on the trends and covariates of age at first birth among various birth cohorts of women ever in union indicates that an early entry into union is associated with young age at first birth and higher number of children born. Multivariate analysis showed that women with highér education, urban residence, and entry into union at age 20 or older among younger cohorts experienced lower risks for first birth compared to others, and that young women are delaying their first birth for longer durations than older women. Work status of women before first birth and the starting age of union seem to be the two major contributory factors for age at first birth. Noticeably, the role of education has changed and is now more significant among younger cohorts than among older ones for first birth timing.

Do girls fall in love with an image of their father? This study tested the hypothesis that, in choosing a partner, people tend to replicate the physical and mental attributes of their opposite-sex parent more than of the same-sex parent. A sample of 314 women, mostly in their late teens and describing themselves as ‘in love’, supplied details of their boyfriends and parents. A tendency for the boyfriend's eye colour to match that of the father more than of the mother was found, as well as a tendency for girls to replicate the age and dominance relationships of the parental partnership in their own relationship. These effects were very small and of marginal significance.

The investigation of women in Flanders born between 1931 and 1962 shows that premarital sexual intercourse has become almost general and that the age at the onset of sexual intercourse is steadily declining. Until the 1970s in spite of the improving contraceptive behaviour of youngsters, the number of women experiencing premarital pregnancy increased and first conceptions occurred at an increasingly younger age. The 1970s marked a turning-point: fewer women became pregnant before marriage or in adolescence. From that time, the contraceptive revolution kept pace with the sexual revolution.

This paper examines the question of whether there are consistent regional variations in the level and shape of the age-specific natural fertility curve using data for 45 less-developed countries drawn from a recent US Census Bureau compilation. In general there do not appear to be such variations. A remarkably consistent age pattern of natural fertility emerges, once the rates have been normalized and an adjustment made for age at first exposure to the risk of pregnancy. The results strongly support Coale's original natural fertility paradigm.

An attempt was made to follow to completion the pregnancies of 2049 women who had amniocentesis for genetic purposes in a single hospital region in northern England. The object of the study was to establish the extent to which complications of pregnancy and fetal problems are attributable to the procedure. Follow-up was complete in 1750 women. Risks to the mother, other than minor abdominal discomfort following the amniocentesis, were minimal. The increase in complications to the pregnancy and delivery, the occurrence of congenital anomalies, spontaneous abortion, and perinatal death, that can be attributed to the procedure of anmiocentesis fall at the lower end of the range previously reported.

The return of fertility post-partum and the incidence of pregnancy were studied in 74 mothers who chose not to breast-feed and who wanted another pregnancy promptly (Group I) and 143 mothers who practised exclusive lactation and decided not to use contraceptives (Group II). Women who breast-fed had much lower pregnancy rates than those who did not. During the first 6 months of the study, there were 53 (72%) pregnancies among the Group I women and no pregnancies among Group II mothers. Only sixteen (11%) women in Group II discontinued the study because of inadequate milk secretion. The low rate of pregnancy and the low rates of inadequate milk secretion in Group II appear related to the special efforts made to promote breast-feeding and give proper instruction to the mothers in this group. The successful lactation is attributed to a high suckling frequency, night feedings, ample mother and child skin-to-skin contact, avoidance of bottle feeding for as long as possible, and the clinical staff's regular emotional support and encouragement to the nursing mother.