This study employed similarity judgments to determine the dimensions used in distinguishing between methods of contraception, and to investigate individual differences in the use of these dimensions. Three groups of subjects rated the similarity of seventeen methods of contraception, and also rated each method on a number of adjective scales. Multidimensional scaling of the similarity judgments revealed two dimensions: one related to effectiveness, expense, and safety, and the other differentiating between standard and non-standard methods of contraception (or natural and non-natural ones). In addition, methods of contraception were arrayed in the space mainly on the basis of physical similarity. Analyses of the rating scales indicated that subjects perceived methods accurately in terms of effectiveness, but were inaccurate in their ratings of safety to the user. Finally, analysis of individual differences indicated that the second dimension was more salient to younger than to older subjects, but did not reveal differences related to religion or contraceptive use.

Using follow-up data on a sample of mothers who gave birth at a Lucknow city hospital, the family size ideals of the women were examined in relation to experienced and perceived levels of child mortality and socioeconomic and demographic characteristics.

The fear of child mortality and their own experience tended to increase the size of family which the mothers considered to be ideal. Lower ideal family size was found among younger women, those who married at later ages and those currently using contraception. Family size preferences were also influenced by rural/urban background, religion, caste, type of family, education, income and occupation of husband and type of housing.

A longitudinal, epidemiological study was carried out in a rural area of Kenya with a population of about 28,000 between 1974 and 1980. Population registration during this time showed that population growth was very high between 1974 and 1978 (4·4% per year) and much lower in 1979 and 1980 (1·1%). Natural increase was nearly as high as in Kenya as a whole (3·7%) in this period. Fertility was somewhat lower than in all Kenya (the crude birth rate was 46 per 1000) while mortality was substantially lower (7 per 1000). Evidence is presented supporting the argument that these low mortality rates are genuine. Levels of temporary and permanent migration are high and probably characteristic for many parts of Kenya. The change in population growth in 1979 and 1980 is probably due to changes in economic conditions leading in particular to less in-migration and to more out-migration.

At the end of the fourth week of the Spring term 1982, 730 female undergraduates at Aberdeen University and 744 female under-graduates at Oxford University were sent a questionnaire enquiring about their sexual behaviour and contraceptive practice. Of the 978 unmarried women who replied, 507 (52%) had experienced sexual intercourse. No contraception had been used by 31% of the women on the first occasion that they had had intercourse; during the 4-week period preceding receipt of the questionnaire 14% of sexually active women had had intercourse on one or more occasions without a contraceptive. Twenty-nine women had been pregnant in the past; two women were known to be pregnant at the time of the survey and twelve women thought that they might be. These findings are discussed and some recommendations are put forward.

One thousand Blacks and 1001 Whites from the southern Brazilian city of Curitiba were studied in relation to migration patterns, ABO and Rh blood groups, and haemoglobin types. Despite a lower socioeconomic level, Blacks migrated more than Whites. Carriers of abnormal haemoglobin types show about the same degree of mobility as those with normal haemoglobin only. As much as half of the genes present among the Blacks of this city may be of European origin, while persons classified as White may have from 3 to 19% of African ancestry.

The study compares the 3 years of birth control practice of 1172 women who underwent early menstrual regulation (MR) and 499 others who accepted contraceptives only (nonMR) from an urban clinic in Bangladesh. About 60% of the women in the sample were followed-up, and their all-method continuation rate was analysed by life table technique. The 3-year overall continuation rate in the MR group (64%) did not differ from that of the nonMR group (62%). In the age groups 25 and over, the continuation rate was higher in the MR group. Among the women who did not desire any more children, the continuation rate in the MR group was significantly higher than that of the nonMR group (80% versus 68%, P< 0·05). Of women with parity greater than two, the MR group had significantly higher continuation rates than the nonMR group. The MR group had higher extended use-effectiveness for IUDs, conventional contraceptives (condom and foam), injectables, and oral contraceptives than the nonMR group. These findings indicated effective contraceptive practice following MR for this urban population. Easy availability of a multimethod service after MR seemed to be important in promoting effective contraception.

As part of a longitudinal study of diet and dental caries, 405 Northumberland children initially aged 11–12 years recorded the time of going to bed on 3 consecutive days on 5 occasions over a 23-month period. The bedtimes were recorded in a personal diary and checked at private interview. Mean bedtime for the 212 females changed from 21 hr 44 min at age 11 years 7 months to 22 hr 11 min at age 13 years 3 months. Bedtime for the 193 males was, on average, 9 min later than that for the females. There was a consistent relation between bedtime and social class, with social class IV + V children going to bed, on average, 14 min later than social class I + II children. When the average age of the children was 13 years 3 months, 13% of them went to bed at or after 23.00 hr, and they were latest to bed on Saturday when their average bedtime was 22 hr 59 min.

Foss (1982) writes:… ‘Guerrero (1974) in a large series showed no relationship of the child's sex to the cycle day of insemination…’. It seems to me that this is ambiguous. If the first day of menstrual bleeding is taken as the time origin, then Foss is correct. But if the biologically more relevant estimated day of ovulation is taken as the time origin, he is not. Using the latter time origin, Guerrero found that for natural inseminations the variance of cycle day of male conceptions was significantly greater than that of female conceptions. In other words, boys are more likely to be conceived at the beginning and end of the fertile period, and girls in the middle. Harlap (1979) has reported findings which seem to confirm those of Guerrero. It has been suggested (James, 1980a, b) that these and other findings would be explained if maternal gonadotrophin levels at the time of conception partially controlled the sex of the zygote.