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.

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.

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.

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.

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.

The paper examines the pattern of breast-feeding among women still in their prime childbearing ages (15–35 years) in Ilorin, the capital city of Kwara state in Nigeria. While breast-feeding is still a common practice among urban women, there is wide variation in the duration of breast-feeding depending on the socioeconomic characteristics of the mothers. Mother's education and father's education have very strong negative associations with duration of breast-feeding. Use of contraception also has a significant independent but negative effect on breast-feeding duration. Christians continue breast-feeding for shorter periods than Muslims. The introduction of supplementary feeding to the infant occurs in this population much earlier than is recommended by various authorities. The dangers inherent in this pattern of infant feeding are discussed.

Differentials in variables concerned with the timing, number, and distribution of fertility by a wide range of socioeconomic, attitudinal, inherited and housing characteristics from the British Family Formation Survey are reported. Variables associated with the couple's housing history and the wife's employment career are becoming more strongly associated with demographic differentials among younger cohorts than traditionally-based ones such as religion or region of residence. Cluster analysis techniques show which groups of family formation variables are strongly associated with particular types of non-demographic ones, and a natural grouping of explanatory variables is derived. The implications of these conclusions for data collection in demographic surveys are discussed.

The effect of educational activities, distance from a genetic centre, and presence of satellite clinics on the growth in genetic services in three regions served (south Alabama, west Florida and southeast Mississippi) was examined. Comparisons of growth trends between the three regions were made in the context of regional differences in clinical and educational variables. Multiple regression analyses of growth in clinical services with these variables were also performed. Results demonstrated that growth in clinical services is greatly enhanced when educational activities are offered in concert with the establishment of a satellite clinic.

In a medieval population of Stockholm only three cases of maternal deaths were proved out of 330 burials of adult females, and only in one of the cases was a contracted pelvis found. However, life table analysis indicates a shorter life expectancy of females in the reproductive ages. This suggests a higher maternal mortality in the Middle Ages than in the 18th and 19th centuries in Sweden.