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.

This study examines the knowledge of sexually transmitted diseases (STDs) among male youths in Malaysia. A self-administered survey was carried out on a sample of 952 never-married males aged 15–24 years. The respondents were asked about their knowledge of STDs, how these diseases get transmitted and their sexual behaviours. The data showed that 92% of the respondents knew of at least one STD (syphilis, gonorrhoea, chlamydia, herpes, genital warts, yeast infection, trichomoniasis or HIV/AIDS). About 95% of them knew of at least one method of STD transmission. Urban and tertiary-educated male youths showed a substantially higher proportion of awareness of STDs and transmission methods compared with their rural and less-educated counterparts. The data also indicated that 10% of the study sample admitted to having had sexual experiences. There were still a large proportion of the respondents who were not aware of STDs other than syphilis and HIV/AIDS and the means of transmission, such as multiple sex partners, including those who claimed to be sexually active. Thus there is a need for more concerted efforts to disseminate information on STDs and transmission methods to a wider audience in Malaysia, especially youths in rural areas.

Using the nationally representative sample of about 15,000 Add Health respondents in Wave III, the hypothesis is tested that masculinity–femininity in adolescence is correlated with sexual orientation 5 years later and 6 years later: that is, that for adolescent males in 1995 and again in 1996, more feminine males have a higher probability of self-identifying as homosexuals in 2001–02. It is predicted that for adolescent females in 1995 and 1996, more masculine females have a higher probability of self-identifying as homosexuals in 2001–02. Masculinity–femininity is measured by the classical method used by Terman & Miles. For both time periods, the hypothesis was strongly confirmed for males: the more feminine males had several times the probability of being attracted to same-sex partners, several times the probability of having same-sex partners, and several times the probability of self-identifying as homosexuals, compared with more masculine males. For females, no relationship was found at either time period between masculinity and sex of preference. The biological mechanism underlying homosexuality may be different for males and females.

The prevalences of hypertension, diabetes and overweight/obesity are increasing in most developing countries, including Bangladesh. Although earlier studies have investigated the factors associated with these three conditions, little is known about whether socioeconomic status is associated with their co-existence. This cross-sectional study analysed data from the 2011 Bangladesh Demographic and Health Survey. An individual was considered hypertensive, diabetic and overweight/obese if their systolic/diastolic blood pressure, fasting plasma glucose concentration, and body mass index were ≥130/80 mmHg, ≥7 mmol/l and ≥23 kg/m2, respectively. Furthermore, individuals who reported taking anti-hypertensive and anti-diabetic drugs were also considered as hypertensive and diabetic, respectively. Two socioeconomic variables were investigated: education level and household wealth quintile. Descriptive analyses and multilevel logistic regression were conducted. Among the 7932 respondents (50.5% female) aged ≥35 years, the prevalences of hypertension, diabetes, overweight/obesity, any one condition and the co-existence of the three conditions were 48.0%, 11.0%, 25.3%, 60.9% and 3.6%, respectively. In adjusted analysis, individuals with secondary (adjusted odds ratio [AOR]: 1.8, 95% confidence interval [CI]: 1.2–2.8) and college or above (AOR: 3.6; 95% CI: 2.2–5.7) education levels had higher odds of the co-existence of all three conditions compared with those with no formal education. Similarly, compared with the poorest wealth quintile, the richer (AOR: 4.6; 95% CI: 2.2–9.4) and richest (AOR: 11.8; 95% CI: 5.8–24.1) wealth quintiles had higher odds of co-existence of these three conditions. Education and wealth quintile also showed significant relationships with each of the three conditions separately. In conclusion, in Bangladesh, hypertension, diabetes and overweight/obesity are associated with indicators of higher socioeconomic status. These findings highlight the importance of developing healthy lifestyle interventions (e.g. physical exercise and dietary modification) targeting individuals of higher socioeconomic status to minimize the burden of these non-communicable diseases.

A sample of 35 South African Negro albinos and a normally pigmented matched control group have been studied for adjustment problems and attitudes towards this inherited condition. The results showed that although the albinos appeared to be as well adjusted as the controls, significantly more of the albino group had adjustment problems of a physical nature indicated by psychosomatic symptoms. Attitudes were found to be reasonably positive. One common local misconception was revealed: that albinos do not die but disappear or ‘vanish away’. There was very little understanding of the cause, mode of inheritance or the problems associated with albinism. It is concluded that relevant genetic counselling should be offered to the Negro albinos to enable them to understand their condition, its implications and the myths which surround it. Because albinism is so common in South Africa the education of the community in this connection is also desirable.

Humans exhibit sex differences in competitiveness, sensation seeking and risk-taking attitude, which are required in sports. These attributes are often linked to prenatal testosterone (PT) exposure. The second-to-fourth digit length ratio (2D:4D) is an indicator of PT exposure. A lower 2D:4D indicates higher PT exposure and vice versa. Males generally have a lower 2D:4D than females. Sensation- and/or thrill-seeking behaviours have also been found to be negatively associated with 2D:4D. Boxing and judo are considered to be high-risk sports. Voluntary participation in judo/boxing in contrast to aerobics can be guided by such behaviours and thus have an association with lower 2D:4D. This cross-sectional study included 167 female students from a military academy in Wrocław, Poland. Of them, 119 had voluntarily chosen aerobic exercise, and 48 opted for judo/boxing. Height, weight and second and fourth digit lengths were measured. Physical fitness was assessed using Eurofit tests. The two groups showed similar physical fitness and body size. However, the judo/boxing group had significantly lower mean 2D:4D values than the aerobics group. It is proposed that voluntary choice of participation in a sport discipline by women could be linked to the ‘organizational’ effect of intrauterine testosterone exposure during prenatal growth.

A time-dependent model of the probability of sexual intercourse, where the probability increases as the time from last intercourse increases, can produce waves in the expected frequency of sexual intercourse on the various dates of the menstrual cycle. These waves occur when the time-dependent model is linked with a period of abstinence, such as is usually found in most societies during the time of the menses. Previously, such waves have been attributed to cyclic hormonal changes in women without considering the full implication of a time-dependent model of sexual intercourse.

Understanding the social and cultural contextual determinants of sexual behaviour of adolescents and young adults is an essential step towards curtailing the spread of HIV. This study examined the effects of one cultural factor, ethnicity, on sexual abstinence, faithfulness, condom use at last sex, and risky sex among young people in Zimbabwe. Data from the cross-sectional, population-based 2005–06 Zimbabwe Demographic and Health Survey were used. Net of the effect of sociodemographic and social–cognitive factors, and using multinomial logistic regression, ethnicity was found to have a strong and consistent effect on sexual behaviour among youth. In addition, the study found that there were ethnic-specific and within-gender differences in sexual behaviour, for both men and women. Shona youth were more likely to be abstinent than Ndebele youth. Compared with Shona youth, Ndebele youth were more likely to have engaged in risky sex. However, Ndebele men were more likely have used condoms at last sex, compared with Shona men. For both men and women, sexual behaviour was more socially controlled. School attendance and religion exerted protective effects on sexual abstinence. For men only, those living in rural areas were less likely to be faithful and more likely to have engaged in risky sexual behaviour than those living in urban areas. The study attests to the fact that ethnic norms and ideologies of sexuality need to be identified and more thoroughly understood. In addition, the study provides evidence that in order to promote safe and healthy sexuality among young people in Zimbabwe, cultural, social and gender-specific approaches to the development of HIV prevention strategies should be seriously considered. Current success in the Abstinence, Being faithful and Condom use (ABC) approach could be strengthened by recognizing and responding to cultural forces that reproduce and perpetuate risky sexual behaviours.

Bangladesh represents one of the few countries in south Asia where the pace of fertility decline has been unprecedented over the last three decades. Although there has been significant reduction in fertility levels at the national level, regional variations continue to persist, especially in Sylhet and Chittagong where the total fertility rates are well above the country average. Using data from three consecutive Bangladesh Demographic and Health Surveys (BDHSs) this paper assesses how fertility patterns in Sylhet and Chittagong differ from the rest of Bangladesh through a marriage cohort analysis of the parity progression ratios, and examines the factors determining the transition rates to higher parity in these two regions. Three cohorts of women are identified: those married during 1965–1974, 1975–84 and 1985–94. The results show that the probability that a woman from the recent cohort in Sylhet or Chittagong who had a third birth will have a fourth birth is nearly twice that of her counterpart in other regions. Social characteristics such as education, occupation, religion and residence have no effect on fertility in Sylhet and Chittagong. Additional period-specific analyses using the 2007 BDHS data show that women in Sylhet are considerably more likely to have a third or fourth birth sooner than those in other divisions, especially Khulna. The findings call for specific family planning policy interventions in Sylhet and Chittagong ensuring gender equity, promoting female education and delaying entry into marriage and childbearing.

This study applied a gender perspective to establish some of the anthropometric, body composition, health and socio-cultural determinants of active ageing. The variable ‘active ageing’ (presence/absence) was created based on cognitive and disability/illness/physical functioning, subjective health, satisfaction with life and productive activity performed, and used in predictive models to establish its relationship with anthropometric variables, physical health indicators and educational level. The sample consisted of 456 home-living individuals (169 men and 287 women; age range 54–75 years) from Madrid and Toledo in Spain. The women had a higher prevalence of obesity than the men (37.6% vs 29.0%), significantly greater fat accumulation in the abdominal area and worst perceived health (p=0.003). The frequency of active agers is higher in men than in women (38.4% vs 21.9%; p<0.001). Men and women were found to have distinctive ageing patterns. Health factors condition the presence of active ageing in women, while education factors are also relevant in men.

The purpose of this study was to show the differences in the mortality rates of children from Catholic and Lutheran families in 19th century Poznań, and to elucidate the causes of these differences. Data from Catholic and Lutheran parish death registers were used. The infant death rate (IDR), neonatal and postneonatal death rates and life table biometric functions were calculated and causes of deaths were characterized. The worst child mortality values (IDR=394.4; neonatal and postneonatal death rates, respectively, 117.1 and 277.4; e0=16.14 years; Crow's Index=2.47) were obtained for the poor Catholic Parish of St Margaret. The lowest infant and neonatal and postneonatal death rates were observed to have occurred in the Catholic Parish of St Maria Magdalena situated in the city's more affluent central area (mortality rates, respectively, 269.9, 93.1 and 176.9; e0=24.63 years; Crow's Index=0.96). The widest range of differences with regard to death rates was found for the Lutheran Parish of St Cross (the infant, neonatal and postneonatal death rates were, respectively, 293.1, 99.1 and 193.9; e0=28.03 years; Crow's Index=0.92). The St Cross Parish encompassed a fairly large area of the city characterized by varying ecological conditions. Among infants and young children from the three studied populations a high frequency of deaths due to infectious diseases, diarrhoeas, dysenteries and tuberculosis were observed. Differences in the mortality of children from Catholic and Lutheran families in 19th century Poznań resulted from ecological conditions, among which water played the most important role, rather than from religious differences.

Research designs to study alcohol use and abuse have included twin, adoption and family history/high risk studies. Results have consistently implied a genetic factor in the aetiology of alcohol abuse. However, less research has been conducted in search of environmental factors. This study uses kinship structure in a large national dataset (the National Longitudinal Survey of Youth) to estimate (using DeFries–Fulker analysis) the extent of the shared genetic, non-shared genetic, shared environmental and non-shared environmental influences on alcohol use. The NLSY kinship sample contained 3890 pairs of cousins, half-siblings, full-siblings and twins between the ages of 14 and 21 in the initial year of the survey (1979). Estimates of heritability (h2) and shared environment (c2) were small to moderate for the entire dataset for both light drinking and heavy drinking behaviour, with h2 estimates slightly higher in each case. Non-shared genetic measures of self-esteem and locus of control accounted for a significant portion of the remaining variance in heavy drinking behaviour. Race and gender patterns showed c2 and h2 estimates that were also small to moderate for both light and heavy drinking behaviour. Significant non-shared effects were found for the White group for heavy drinking behaviour, and for male pairs for both heavy and light drinking behaviour. Additionally, implications and future directions are discussed.

The Standard Progressive Matrices test was standardized in Estonia on a representative sample of 4874 schoolchildren aged from 7 to 19 years. When the IQ of Estonian children was expressed in relation to British and Icelandic norms, both demonstrated a similar sigmoid relationship. The youngest Estonian group scored higher than the British and Icelandic norms: after first grade, the score fell below 100 and remained lower until age 12, and after that age it increased above the mean level of these two comparison countries. The difference between the junior school children and the secondary school children may be due to schooling, sampling error or different trajectories of intellectual maturation in different populations. Systematic differences in the growth pattern suggest that the development of intellectual capacities proceeds at different rates and the maturation process can take longer in some populations than in others.

The basal body temperature was recorded by 1353 healthy fertile women aged 18 to 49 years inclusive through 12,247 cycles. The post-ovulatory (hyperthermic) phase of the cycle was significantly longer by 1·31 days in cycles with a slow or staircase rise of temperature than in cycles with an acute rise. The hyperthermic phase increased in length in a rectilinear fashion from 10 to 13 days as the total cycle length rose from 22 to 29 days; over total cycle lengths from 29 to 33 days the length of the hyperthermic phase remained around 13 days.

The associations between cigarette smoking before and during pregnancy and maternal body size (pre-pregnancy weight status, end of pregnancy weight status, weight gain during pregnancy) and newborn size (birth weight, length, head circumference, arcomial circumference), as well as birth modus, were tested in 7803 single full-term births in Vienna. Nicotine consumption before and during pregnancy was found to be associated with smaller and lighter newborns, although maternal weight status and weight gain during pregnancy was signi.cantly higher in smokers. Furthermore, a higher incidence of Caesarean sections was found in smokers. A reduction in the number of daily smoked cigarettes was associated with a lower percentage of low weight newborns (<2500 g).

Despite the increasing interest in the determinants of adolescent undernutrition in low- and middle-income countries, a comprehensive multi-level overview at the country level is missing. Using the nationally representative 2014 Nepal Adolescent Nutrition Survey, this study aimed to provide a comprehensive overview of the sociocultural and economic determinants of stunting and thinness of adolescent boys and girls in Nepal. Multivariate logistic regression models were used to estimate the associations between multiple individual, household and community determinants and stunting and thinness among 3773 adolescents aged 10–19 years (1888 boys and 1885 girls). The prevalence rates of stunting and thinness indicated suboptimal nutritional status and an inadequate growth environment in Nepali adolescents. The results highlighted an association of paternal occupation and education, household income, number of earning household members, geographical place of residence, caste/ethnicity and nutritional knowledge with stunting, with higher odds for males and older adolescents. Paternal occupation, education, household income, geographical region, caste/ethnicity and nutrition knowledge were associated with thinness, with higher odds for males and younger adolescents. The findings underscore the importance of involving adolescents, their parents and their communities in interventions. Such interventions should not only be aimed at improving adolescent nutrition but also at optimizing adolescents’ growth environment for better health and development. Future research should focus on context-specific causal pathways and mechanisms through which sociocultural and economic determinants influence nutritional outcomes within broader societal, cultural and political settings. A longitudinal approach, including a range of dietary and nutrition indicators would allow understanding how and when the relative importance of these factors change during adolescence.

Child marriage has significant negative impacts, not only for girls, but also for a range of development outcomes. This study aimed to assess, in a more detailed way than done so far, the magnitude of the relationship between child marriage and total fertility in multiple countries representing diverse settings. Data from the most recent Demographic and Health Surveys in the fifteen countries of interest were used. Analysis was restricted to a subsample of women aged 35–49 years in order to capture completed fertility. Poisson regression was conducted to estimate the impact of each additional year of early marriage on the total number of births women have, controlling for selected sociodemographic characteristics. Counterfactual analyses were carried out to estimate the reduction in the number of children that women would have over their lifetime in the absence of child marriage. Controlling for socioeconomic and other characteristics, girls who marry as children have more children over their lifetime than women marrying after the age of 18. Nationally, across fifteen countries, the reduction in total fertility from ending child marriage ranges from 0.24 to 1.06 children per woman. The simulated change in total fertility that would result from ending child marriage tends to be higher in countries that have a higher incidence of child marriage.

This study examines the delay between first marriage and first live birth in China among a sample of women who married between 1980 and 1992. Most couples in China only use contraception after the first child is born. Most sample women had their first child within 2 years of marriage. However, there are significant rural–urban differences in the first birth interval, indicating that there was most probably deliberate fertility regulation after marriage among many urban couples. Survival analysis shows that place of residence, level of education, age at first marriage and marriage cohort affect the first birth interval.

The hypothesis that the month-specific rate of return to ovarian cyclicity after childbirth is causally related to suckling pattern was tested for a population of New Mexican women recruited within the service area of New Mexico Highlands University and for a nationwide USA subpopulation of women recruited through membership of the Couple to Couple League (CCL). Survival analysis for time-dependent covariates was used, and significant predictors of the first postpartum menses were found. Important differences were detected in the suckling pattern for the two groups and a 5:2 differential was found in their respective rates of menstrual cycle recovery. Although the two groups were comparable perinatally, daily and time-windowed breast-feeding performance fell off at twice the rate for the New Mexico population when contrasted with the CCL sample. For both populations, the introduction of solid feeds was a strong and significant predictor of returning menstrual cyclicity, independent of suckling pattern.

Twenty-three girls and thirteen boys, aged between 4 and 9 years, gave urine samples which were measured by HPLC for adrenaline, noradrenaline, cortisol and cortisone on a school day and on a home day. Home levels of noradrenaline, cortisol and cortistone were consistently higher than school levels. Cortisol was positively correlated with adrenaline and noradrenaline at home, but not at school. These results may suggest that the school day represents a stimulating but comparatively structured environment with little negative affect, while the home day is characterised by stimulation but relative uncertainty in social interactions.