Researchers in psychology have focused a great deal of attention on the potential greater predisposition to achievement among first-born children relative to their siblings. Focusing on the United States as an example, a time series of the first birth ratio is used to show how the changing prevalence of first births relative to higher order births has altered the composition of birth cohorts, and the ratio is decomposed into four factors. Results show that the ratio increased significantly in the 1960s and early 1970s, but changed only slightly in the following decades. While more recent birth cohorts are composed of larger proportions of first-born children, the majority of children are still born as siblings. Contrary to expectations, the primary source of change was the proportion childless rather than decreasing higher order birth rates.

A birth order and sexual orientation relationship has been demonstrated numerous times in men, but a related variable, parental age (i.e. age of parents when the participant was born), has been less studied and has demonstrated contradictory results. In this research, the relations among birth order, parental age and sexual orientation were examined in a national probability sample of the US (Kessler, 1994; Kessler et al., 1994) and in a Canadian sample of homosexual and heterosexual men closely matched on demographic characteristics (Blanchard & Bogaert, 1996a). In both studies, an interaction between birth order and parental age was observed in men, such that there was positive association between number of older siblings and the likelihood of homosexuality, but this association weakened with increasing parental age. No significant effects were observed for women. The results are discussed in relation to recent theories of the birth order/sexual orientation relationship.

The pill is the most popular family planning method in Bangladesh. However, the failure rate of this method in Matlab, a typical rural area, has been found to be very high. It is estimated that with the current level of failure of the pill and other temporary contraceptives in Matlab, it is unlikely that fertility in Bangladesh will come down to replacement level without a change in contraceptive method mix. It is, therefore, important to know the reasons for the high failure in pill use. Data for this study came from a case-control study in Matlab. A pill failure was considered a case, and no-failure was considered a control. The study included 167 cases and 167 controls. In addition, five focus group discussions were conducted to supplement the data collected from the cases and controls to gain a deeper understanding of pill failure. Results of the analysis of both quantitative and qualitative data suggested that the following were the risk factors for pill failure: no mobility of women, poor knowledge of women about the effectiveness and consequences of drop-out from pill use, weak confidence in the pill, a gap between the use of subsequence pill cycles, delay in starting the pill after menstruation for the first use, not taking any measures consistently for missing the pill, and not following the arrow sign given on the pill cycle. Extensive training of field workers and pill users, covering the reasons for pill failure identified in this study and strong supervision of the work of field workers, is likely to reduce the rate of pill failure in Bangladesh. Also, information, education and communication services for users, and management of side-effects, may be helpful in reducing pill failure.

It has been established that the probability that a man is homosexual is positively related to his number of older brothers, but not older sisters when the brothers are accounted for. This is known as the ‘fraternal birth order’ effect. In the past, efforts have been made to explain this phenomenon in terms of several alternative biological hypotheses and a psychosocial hypothesis. This note examines how well these hypotheses accommodate the fraternal birth order effect. It is concluded that: (1) the evidence for the hypothesis of maternal immunoreactivity to the male fetus is weak; (2) the evidence for the intrauterine hormone exposure hypothesis is also weak; (3) the evidence for the hypothesis of postnatal learning is stronger. Lastly, there seem likely to be causes common to male homosexuality and paedophilia. They may include sexual (or quasi-sexual) experience in childhood or adolescence.

I have recently written: ‘there seem likely to be causes common to male homosexuality and paedophilia. They may include sexual (or quasi-sexual) experience in childhood or adolescence’ (James, 2004). These words are rather vague and I wish to clarify them here.

A study on perceptions, attitudes and treatment-seeking practices related to schistosomiasis was conducted among the Wasukuma in the rural Magu district of Tanzania at the shore of Lake Victoria where Schistosoma haematobium and mansoni infections are endemic. The study applied in-depth interviews, focus group discussions and a questionnaire survey among adults and primary school children. The perceived symptoms and causes were incongruous with the biomedical perspective and a number of respondents found schistosomiasis to be a shameful disease. Lack of diagnostic and curative services at the government health care facilities was common, but there was a willingness from the biomedical health care services to collaborate with the traditional healers. Recommendations to the District Health Management Team were: that collaboration between biomedical and traditional health care providers should be strengthened and that the government facilities’ diagnostic and curative capacity with regard to schistosomiasis should be upgraded. Culturally compatible health education programmes should be developed in collaboration with the local community.

Using data from a survey of deaths of children less than 5 years old conducted in 1997 in a county in Shaanxi Province, China, this paper examines gender differences in child survival in contemporary rural China. First, excess female child mortality in the county in 1994–96 is described, followed by an analysis of the mechanisms whereby the excess mortality takes place, and the underlying social, economic and cultural factors behind it. Excess female child mortality in this county is probably caused primarily by discrimination against girls in curative health care rather than in preventive health care or food and nutrition. Although discrimination occurs in all kinds of families and communities, discrimination itself is highly selective, and is primarily against girls with some specific characteristics. It is argued that the excess mortality of girls is caused fundamentally by the strong son preference in traditional Chinese culture, but exacerbated by the government-guided family planning programme and regulations. This suggests that it is crucial to raise the status of girls within the family and community so as to mitigate the pressures to discriminate against girls in China’s low fertility regime. Finally, the possible policy options to improve female child survival in contemporary rural China are discussed.

Consanguineous marriage is traditionally common throughout the Eastern Mediterranean region, especially in the mainly Muslim countries. To date, there is little information on consanguinity in Yemen. The aim of this study was to ascertain the rate of consanguineous marriage and average coefficient of inbreeding in Sana’a City, Yemen. A population survey was conducted with the intention of covering married couples resident in Sana’a City by means of a multi-stage random sampling technique. A total of 1050 wives and husbands were interviewed on consanguinity in their households. The total incidence of consanguinity was 44·7% (95% CI 41·7–47·7%) with first-cousin marriages constituting 71·6% of the total consanguineous marriages and 32% of all marriages. Paternal parallel first cousins (Type I) accounted for 49% of first-cousin marriages. The average coefficient of inbreeding (F) was 0·02442. The incidence of consanguinity is relatively high in Yemen with predominantly first-cousin marriage. This might be related to the deeply rooted social and cultural beliefs in the country.