A gender gap has been found in mathematics (boys outperform girls) that has prevailed across countries for many decades. Whether this gap results from nature or nurture has been hotly debated. Using the evidence of PISA 2003 and the gender equality index of 2003, some researchers have argued that an improvement in gender equality reduces the gender gap in mathematics. This study used five waves of country-level PISA data and, controlling for country fixed effects, found no evidence to support this argument. Furthermore, individual data for PISA 2012 and the multilevel data model were used. The conclusion drawn also does not support the argument. In fact, the relationship between gender equality and the gender gap in mathematics vanished after PISA 2003.

This study examines the short- and long-term effects of war-induced and war-unrelated migration on fertility outcomes using data from two peri-urban municipalities of Greater Luanda in Angola. In the short term, results from multi-level discrete-time logistic regression models indicate that net of other factors, war-unrelated migration is associated with a lower probability of birth than war-induced migration in a given year. Similar results are obtained when the effects of migration are lagged by a year. At the same time, the effects of war-triggered migration do not differ significantly from those of not migrating in a given year but are statistically significant when the effects of migration are lagged by a year. In the long term, the effects of migration experience on cumulative fertility are negligible and not statistically significant net of demographic and socioeconomic variables. Interpretations of the results are offered in the context of Angola and their broader implications are reflected on.

Some recent data are presented on the size and selected sociodemographic characteristics of the Afghan refugee population in Pakistan. Although the official figures show that there were 3·27 million registered Afghan refugees in Pakistan, it is estimated that the actual number may be as high as 3·6 million. There is an excess of females over males, mainly due to war-related activities and excessive casualties particularly among males. While infant and childhood mortality rates are declining and are lower than the levels prevalent in Pakistan, as well as in Afghanistan during the prewar period, the fertility levels among Afghan refugees seem very high indeed.

This study focuses on how older adolescent girls access and utilize social capital to develop resilience against teenage pregnancy in Begoro, Ghana. A survey of 419 non-pregnant girls aged 15–19 years, selected using a multi-stage cluster sampling technique, was conducted in 2012. Qualitative data were gathered through in-depth interviews with ten girls purposively selected from the survey respondents. Parents, relatives, teachers and religious groups were found to be important sources of social capital for the non-pregnant girls in developing resilience against teenage pregnancy. In addition, resilient girls tended to rely on multiple sources of social capital. It is recommended that stakeholders and policymakers in Ghana ensure that these significant sources of social capital in adolescent girls’ sexual experience are equipped with the right information to help girls decrease the risk of teenage pregnancy.

Consanguinity has been shown to increase homozygosity and to reduce genetic variation in a group, which may protect against the expression of recessive genes that can lead to genetic disorders. Consanguineous marriages are practised widely in Kuwait. The major aim of this study is to delineate the association of consanguineous marriages with congenital disabilities in different Kuwaiti population subcultures. A total of 9104 married Kuwaiti females aged 15–79 years from different backgrounds were selected at ten primary health care centres from six governorates in Kuwait. Data were collected using a questionnaire and analysed with chi-squared tests. The data indicate significant differences in the occurrence of genetic diseases in consanguineous couples' offspring (4.88%) compared with those of non-consanguineous couples (4.13%) (p<0.002). The results also show significant differences in frequencies of genetic/environmental diseases in consanguineous couples' offspring (8.59%) compared with those of non-consanguineous couples (8.23%) (p<0.005). No significant differences between the two groups regarding environmental diseases were observed. A higher frequency of genetic diseases was found in first- (6.97%; p<0.001), second- (6.78%; p<0.001) and third-cousin (6.46%; p<0.022) couples' offspring compared with those of non-consanguineous couples. The frequency of congenital disabilities in the offspring of couples from consanguineous marriages (2.9%) is higher than that in the offspring of non-consanguineous marriages (2.3%). But this difference is not significant at the 0.05 level. First-cousin marriages have the highest frequency (3.5%) of congenital disabilities compared with other kinds of marriages (2.1–2.3%). Differences across groups are significant (p<0.036). Significant differences are found for first-cousin couples in both physical (2.37; p<0.042) and mental (0.74; p<0.037) disabilities compared with non-consanguineous couples. No significant differences were observed in deafness and blindness disabilities. The data show no significant differences between second- and third-cousin and non-consanguineous couples in physical, mental or deafness and blindness disabilities. There are no significant differences in the percentages of offspring with congenital disabilities in consanguineous and non-consanguineous marriages across sub-population groups for the total of four types of congenital disability.

The surname is a cultural trait that is extremely useful for historical and linguistic studies and can effectively be used as a genetic marker. In many human populations the surname is inherited in the paternal lineage, and can therefore be considered a marker for the Y chromosome. In this study, surnames were recorded from the white pages of telephone directories in current use in Corsica in 1993. All surnames present in thirteen villages scattered over the whole island and covering the main historical regions were transcribed. Surname variability was found to be higher in coastal villages, and lower in more isolated communities. The isonymy detected among the thirteen villages allowed the calculation of kinship values, visualized in a tree showing two main clusters, one referring to the northern villages and one encompassing the villages of the south. The pattern reflects the administrative division of the island, with the exception of Vico, which belongs to the southern administrative region but is geographically close to the northern villages, and Ghisoni, which belongs to the northern district but is more similar to the village of Bastelica in the southern district. The data presented here show a structure in the surname distribution that is in substantial agreement with the geographical patterns. The kinship values are consistent with a moderated gene flow among villages producing a surname structure according to the geographic features of the territory.

In order to examine the prevalence of HIV infection and associated risk factors amongst Spanish female prostitutes a multicentre (n=22) cross-sectional study was conducted between November 1989 and January 1991. Data collected included socioeconomic characteristics, sexual behaviour and health status together with blood samples. A total of 1633 prostitutes were recruited into the study. Of these, 1433 (87.8%) consented to blood samples being taken and 180 (12.6%) were HIV positive. HIV seroprevalence was 54.7% for intravenous drug users (IVDUs) versus 3.7% for non-IVDUs. Previous imprisonment, hepatitis B and a partner who was an IVDU were significant predictors of HIV infection according to multivariate logistic regression models.

The relationship between female labour force participation, and other socioeconomic factors, and the probability of having a third birth is examined, using British data collected in the 1980 Women and Employment Survey, by hazard regression modelling with time-varying covariates. The results demonstrate the strong association between demographic factors, e.g. age at first birth and birth interval and subsequent fertility behaviour. Education appears to have little effect. Surprisingly, women who have spent a higher proportion of time as housewives have a lower risk of having a third birth. This finding is in sharp disagreement with the conventional expectation that cumulative labour force participation supports lower fertility. These findings are briefly compared with similar research carried out in Sweden.

Although the IUD is an extremely effective and low-cost contraceptive method, its use has declined sharply in Kenya in the past 20 years. A study tested the effectiveness of an outreach intervention to family planning providers and community-based distribution (CBD) agents in promoting use of the IUD in western Kenya. Forty-five public health clinics were randomized to receive the intervention for providers only, for CBD agents only, for both providers and CBD agents, or no detailing at all. The intervention is based on pharmaceutical companies’ ‘detailing’ models and included education/motivation visits to providers and CBD programmes, as well as provision of educational and promotional materials. District health supervisors were given updates on contraceptives, including the IUD, and were trained in communication and message development prior to making their detailing visits. Detailing only modestly increased the provision of IUDs, and only when both providers and CBD agents were targeted. The two detailing visits do not appear sufficient to sustain the effect of the intervention or to address poor provider attitudes and lack of technical skills. The cost per 3·5 years of pregnancy protection was US$49·57 for the detailing intervention including the cost of the IUD, compared with US$15·19 for the commodity costs of the current standard of care – provision of the injectable contraceptive depot-medroxyprogesterone acetate (DMPA). The effectiveness of provider-based activities is amplified when concurrent demand creation activities are carried out. However, the cost of the detailing in comparison to the small number of IUDs inserted indicates that this intervention is not cost-effective.

In considering the evolutionary implications of the sex ratio (as opposed to the evolutionary implications of there being two sexes) a dual approach is required. On the one hand we need information about the variability of the sex ratio and to what extent that variability is genetically controlled, and on the other hand we need a theory which embraces the evolutionary consequences of a heritable variability, and which, ideally, is able to account for the observed situation by showing that it corresponds to a stable solution of the theoretical equations.

The relationship between breast-feeding and subsequent pregnancy in East Bhutan is examined, against the background of local attitudes to family planning. Ninety-eight mothers who had given birth 30–36 months earlier were interviewed. Semisolid supplementary feeding was introduced at a median age of 3 months. Median total duration of breast-feeding was 28 months, and day and night breast-feeding on demand was continued throughout. Median duration of postpartum amenorrhoea was 12 months, and was associated with the timing of the introduction of supplementary foods.

There was a significant association between the occurrence of a subsequent pregnancy and early termination of breast-feeding. The relationships between breast-feeding pattern and pregnancy interval are complex, and their relative influence changes with time. During the first year postpartum, infertility during lactational amenorrhoea is important. During the second year there is a strong negative effect on lactation from the next pregnancy. The only important reason for ceasing to breast-feed within 2 years seems to be a new pregnancy.

The rise in Caesarian section rates has been much greater in the United States than in Britain. This article analyses the reasons for these trends and finds they are not clearly related to good medical practice. It is concluded that it should be a cause for concern if rates rise above 6% of live births. In this case operations must be shown to be in the best interests of the mothers and their babies.

A controlled comparison study was completed using interview data from 80 women each experiencing their first pregnancy whilst single. Half of the women continued their pregnancy, in some cases marrying the father. The other half obtained an abortion. Two interviewers, one male and the other female, each completed an equal number of interviews with both groups of women.

The women selected for the study had the following traits: (1) never married before this, their first conception; (2) aged 17–30 years; (3) white ethnic status; (4) had not delivered or terminated the pregnancy at the time of the interview. The sample consisted of volunteers from the ante-natal and gynaecology clinics at St Mary's Hospital Medical School and Samaritan Hospital for Women, London, W.2, and Kingston and Richmond Hospitals, Surrey.

Almost all topics examined in the pre-conception period turned out to be characteristic of women experiencing their first illegitimate conception, whether or not they continued the pregnancy. A detailed examination of contraceptive background revealed no significant differences between the two groups of women, with two exceptions. Women having abortions were more likely, at the time before they conceived, to have accepted the idea of using contraception. A small number of these women were also more likely to have made an effort to obtain a clinical contraceptive device.

The only other pre-conception factor found to be associated with abortion involved the relationship with the father up to the time of conception. If that relationship was uncertain, less meaningful than previous ones, or a social rather than a romantic one, the woman was more likely to terminate the pregnancy.

In contrast to the pre-conception period, almost all analyses of events subsequent to conception revealed differences between the two groups of women. Both concern over being discredited by other people and concealing information about the pregnancy were traits associated with having an abortion, but in a qualitative rather than an absolute sense. These aspects of social stigma were common to all women before the first pregnancy test, but became more evident amongst women having abortions once the pregnancy had been clinically confirmed. Both concern over being discredited and concealing the pregnancy were experienced in relation to particular persons. For women terminating their pregnancies these were usually their parents.

The degree of acceptability of abortion and unmarried motherhood differed between the groups, but they were similar in their views on the acceptability of marriage with pregnancy and adoption. These four alternatives were further examined in terms of the women's preferences and here the two groups differed.

Finally, there were differences between the groups in the effect of the pregnancy on the relationship with the putative father. Women having abortions were more likely to find themselves in a relationship that had either finished or was likely to finish after the father knew of the pregnancy. Some were pregnant by a social acquaintance which precluded either marriage or joint parenthood.

The findings are discussed in terms of the relationship between contraception and abortion for the single woman and consideration is given to the implications for fertility research and contraceptive and pregnancy services.

The purpose of this study was to assess the utility of using maternal assessments of infant birth size as proxy measures for birth weight in Ecuador, a country in which a sizeable proportion of births take place at home, where birth weight is typically not recorded. Four thousand and seventy-eight women who experienced a live singleton birth between January 1992 and August 1994 were interviewed in the Ecuador Demographic and Maternal–Child Health Survey. All women were asked if their child was weighed at birth, his/her weight, and what they considered to be his/her birth size relative to other newborns. The consistency between birth size and birth weight measures was assessed, and the differences between infants with and without reported birth weights were explored. The authors conclude that maternal assessments of birth size are poor proxy indicators of birth weight. Estimates of low birth weight based on maternal assessments of birth size as very small should be recognized as underestimates of the actual prevalence of low birth weight. Moreover, infants for whom birth weights are missing should not be considered similar to those for whom weight was reported. Those without reported birth weights are more likely to be low birth weight. Thus, relying solely on reports of numeric birth weight will underestimate the prevalence of low birth weight.

Owing to the rarity of triplets and higher multiple births, most studies of multiple births have been focused on twins. One of the fields of study which has attracted considerable interest is the association of biosocial factors with twinning. Although much work has been done in this field in Caucasian populations, very little investigation has been carried out in tropical areas, some of which have the highest twinning rates on record. In this paper, the results of recent studies on twinning conducted in Aberdeen (Scotland) and Ibadan (Nigeria) will be presented to illustrate the influence of some biosocial factors on twinning.

This study aimed to assess knowledge, attitude and practice related to consanguinity among multiethnic health care providers in the Kingdom of Saudi Arabia. Using a cross-sectional study design, a validated, self-administered close-ended questionnaire was randomly distributed to health care providers in different health institutions in the country between 1st August 2012 and 31st July 2013. A total of 1235 health care providers completed the study questionnaire. Of the 892 married participants (72.23% of total), 11.43% were married to a first cousin, and were predominantly Arabs, younger than 40 years and male. Only 17.80% of the patients seen by the health care providers requested consanguinity related counselling. A knowledge barrier was expressed by 27.49% of the participants, and 85.67% indicated their willingness to have more training in basic genetic counselling. A language barrier was expressed as a limiting factor to counselling for consanguinity among non-Arabs. The health care providers had a major dearth of knowledge that was reflected in their attitude and practice towards consanguinity counselling. This finding indicates the need for more undergraduate and postgraduate medical and nursing education and training in the counselling of consanguineous couples. It is recommended that consanguinity counselling is included in the current premarital screening and counselling programmes in the Kingdom.

A comparative study has been made of Japanese and American maternal behaviour and infant development from birth to 3 months of age, especially in relation to infant feeding practices. The effect of cultural differences on the initiation and prolongation of breast-feeding is discussed and consideration is given to factors such as alertness of the mother during the birth, post-partum procedures in hospital, family sleeping arrangements and the general style of maternal care. The possibility of a post-partum “critical” period, and its effect on infant behaviour and development, is discussed.

There are a number of reasons for anticipating that contact by women in developing country settings with modern maternal–child health (MCH) services will lead to increased use of family planning services. Indeed, the expectation of such a relationship underlies the integrated service delivery strategy that has been adopted on a more or less global basis. However, the available empirical evidence in support of this proposition is inconclusive. This study re-examines this issue in Morocco. Household survey data and data on the supply environment for health and family planning services gathered in 1992 are analysed in the study. A full-information maximum likelihood estimator is used to control for the possible endogeneity of health care and contraceptive choices. The findings indicate a substantial and apparently causal relationship between the intensity of MCH service use and subsequent contraceptive use. Policy simulations indicate that sizeable increases in contraceptive prevalence might be realized by increasing the coverage and intensity of use of MCH services.

Analyses of the height variation of 16-year-old members of the British National Child Development Study revealed a number of biological and social variables which associated with stature. After multiple regression analyses only eight variables, namely social class, family size, tenure (owner occupied or one of several types of rented home), crowding status, number of children sleeping in the bed, region of the country, sex of child, and pubic hair rating, remained significant. The total variation explained by these biosocial variables was 37·5%.

The Principality of Andorra is a small European state located in the central Pyrenees. Since the Middle Ages, it has retained political independence from its two neighbouring countries, France and Spain. Until recently, Andorra maintained a relative stable population and was dependent upon agriculture and livestock. Since 1940, however, a marked change in these conditions has given rise to an explosive increase in the size of the population and traditional systems of production have been replaced by tourism, commerce and service industries. These changes have influenced the model of nuptial seasonality. Based on data from 10,188 marriage certificates covering a period from 1606 to 1960, nuptial seasonality was assessed by estimating Henry’s seasonality coefficient. Temporal and geographic changes in the seasonality model were assessed using linear regression analysis and analysis of variance. In addition, the Ũhindex – an estimate of the intensity of the seasonality model – is proposed to assess changes in the different seasonality models. The results indicate a relaxation of seasonality over time and in those parishes in which substantial demographic and socioeconomic change has occurred in recent years, suggesting a strong dependence of seasonality on the system of production.