Coital Rates Research Articles

Legal and social implications of adolescent sexual behavior

Chastity requirements among adolescents are primarily limited to females and derive more from cultural determiners than biological harm. Historical and anthropological literature suggests that this demand is patriarchally derived, based both on primitive magical fears over hymenal and menstrual bleeding and economic interests in virgin brides and the paternity of potential inheritors.The contemporary rise in adolescent coital rates reflect a shift away from this cultural past toward a greater sexual egalitarianism as a component of expanding womens' rights. Adolescent males have always enjoyed a high coital rate; change has selectively occurred among girls.Significant change in parent‐offspring relationships is also evident in a move away from an arbitrary age of majority to a recognition of developmental maturity and the capacity of selected minors to function as adults. The expanding body of minors‐consent‐to‐health‐care law is supportive of this thesis and contributes to the concept of minor's rights and the mature minor doctrine.

Maternal age, parity, social class and sex ratio.

SUMMARY AND CONCLUSIONS:1. Analysis of variance has been performed on data on more than 1 million Scottish births simultaneously classified by sex, maternal age, birth order and social class.2. Although there is a, probably significant mean shift in the sex ratio with social class, the fluctuation between years, age‐classes and parity‐classes are very large in comparison. The shift is in the expected direction, viz. higher in the upper social classes and lower in the lower social classes.3. Data have been cited, and fresh data accumulated, on very large samples of white U.S. live births (each of more than 20 million births). These suggest that there is a small decline in sex ratio independently and significantly with both maternal age and birth order.4. In general, the decline with maternal age cannot be detected in U.S. samples representing only one year's births (numbering roughly 3 million births).5. It seems reasonable to suppose that the causes of such declines may be present in the Scottish data, but that their effect has been swamped by sampling error.6. The most important result in the present study is the failure to detect any meaningful association between sex ratio and social class.7. It is inferred that if there is such an association in white births, it is not very large and therefore cannot be responsible for bias in the data of Garfinkel and Selvin.8. Accordingly it is argued that the decline in sex ratio with paternal age detected by these authors and others may be real rather than a statistical artifact.9. Such an association would be compatible with the hypothesis that the sex of EL human zygote is somehow dependent on timing of insemination and hence on coital rate.

Explaining Premarital Sexual Intercourse among College Students: A Causal Model

A model to explain how college students come to engage in premarital intercourse is estimated separately for men and women and by interpersonal commitment (engaged or going steady versus neither). The major finding is the large impact of friends' on students' own behavior, both directly and as perceptions of friends' coital behavior mediate (1) religious values, and (2) more structural kinds of factors (off-campus residence, dating, fraternity lsorority membership). Most researchers now agree that there has been an increase in coital rates among the unmarried since the early sixties, at least among women (Bell and Chaskes; Christensen and Gregg; Reiss and Miller; Robinson et al.). Some, however, challenge the magnitude and meaning of this change, denying in particular that it indicates a sexual revolution. For example, although Simon et al. report a rise in premarital coitus among white college women, they deny that this reflects a basic attitudinal change since the increase is almost exclusively within established courtship patterns and not in casual sex. Others qualify the idea of a revolution by pointing to feelings of regret among some unmarried women with coital experience (Bell and Chaskes), by suggesting that the magnitude of change is exaggerated by the myth of an abstinent past (Cutright), or by directing attention to persistent (although declining) nonpermissive attitudes in the population at large (Alston and Tucker; Reiss, c). (A public opinion poll *Partial support for this research was provided by a grant from the Russell Sage Foundation. Computer support was provided by the Indiana University Wrubel Computing Center. The authors wish to thank Ira L. Reiss, Martin S. Weinberg, and William Strahle for helpful comments on an earlier version of this paper.

Coital rate, cycle day of insemination and sex ratio.

SummaryGuerrero (1975) has cited a wealth of direct data supporting the hypothesis that timing of insemination is related to the sex of the resulting zygote. It is argued here that if this hypothesis were correct, then parental coital rate would be associated with the sex of the resulting children. It is suggested here that empirical data support this inference and hence support the hypothesis.It is estimated that if Pmale (the probability that a zygote will be male) declines linearly across the fertile period, that decline is from about 0·57 to 0·45.

Intermediate fertility variables and marital fertility rates

Summary Using relatively simple mathematical techniques, an analysis is made of a comprehensive reproductive model that describes the relationships between a set of intermediate fertility variables and the marital fertility rate. Two types of intermediate fertility variables are distinguished: (1) biological parameters and (2) control variables. A homogeneous model is outlined first. Next, this version is extended to include heterogeneity with respect to fecundability and coital rates. Tests of the model with data from two historical populations (i.e. Crulai, 1674-1742, and Tourouvre au Perche, 1665-1765) demonstrate that the model is, indeed, consistent with observed reproductive behaviour in actual populations.

Letter: Coital rate and sex of offspring.

Letter: Coital rate and sex of offspring.

Sex Ratios in Large Sibships, in the Presence of Twins and in Jewish Sibships

SummaryIt is argued that the author's hypothesis relating timing of insemination (and hence coital rate) to the sex ratio of the resulting children is supported by the available data on the variation of sex ratio with (1) sibship size, (2) the presence of twin sibs, and (3) parental adherence to the Jewish faith.

Sex ratio and the sex composition of the existing sibs.

1. It is well established that p, the probability of a male birth, declines with birth order. It is suggested here that this decline occurs within individual sibships (Poisson variation). 2. Other workers have also offered good evidence that (at least in some samples) p correlates positively between adjacent births within sibships (Markov association). 3. The present paper suggests that in addition, some couples have higher values of p than others. In other words, there is Lexis variation in p between couples. It is estimated that this Lexis variation augments the variance (contingent on the Markov process above) by a value of less than 0-002. 4. Data on sex ratio by the sex composition of the pre-existing children are interpreted to support the author's hypothesis that coital rate of parents is related to the sex ratio of their children. 5. However if the decline in sex ratio with maternal age were entirely due to the concomitant decline in coital rate, the variation in p between couples seems greater than could be accounted for by the observed variation between couples in coital rate. It is concluded that sex ratio depends on other factors besides coital rate. 6. It is noted that (when sibship size and birth rank are controlled) MF birth intervals are particularly long, and FM birth intervals particularly short, MM and FF intervals being of intermediate length.

Marital coital rates, spouses' ages, family size and social class.

Abstract Data were provided by 2 surveys on human sexual behavior. Variation of marital coital rate with each of four demographic variables (wife's age, husband's age, parity and social class) was analysed when the other three were held constant. The following results were obtained: 1. When social class and parity (number' of children) are held constant, coital rates decline more rapidly with husband's age than with wife's age. 2. When duration of marriage is held constant, coital rate correlates positively with parity.

Sexuality and reproduction.

The relationship between coital rates, a quantitative index of sexuality, and the quality and quantity of reproduction is discussed in terms of sex ratio, delayed fertilization, frequency of intercourse, intercourse distribution within the menstrual cycle, acceleration of ovulation, and the quality of intercourse. Frequency of intercourse affects chances of conception, but its effect on twinning and sex ratio are unclear. Current research on reproduction offers little evidence of the effect of intercourse quality on reproduction in fully fecund individuals; research into the possible effect on reduced fecundity would be desirable.

Sexual Side-Effects of Clomipramine (Anafranil)

An attempt was made to measure the effects of depressive illness and of clomipramine (Anafranil) therapy in doses of 30 mg and 75 mg daily on sexual appetite and performance. A special questionnaire was devised to gather information on sexual habits before illness, during illness and following treatment. It proved difficult to differentiate between the beneficial effects of recovery from depression and the possible adverse drug effects on sexual activity. Two patients dropped out of the study because of supposed sexual side-effects--a male with ejaculatory difficulties and a female with orgasmic impotence. Fifty-four patients completed the sexual questionnaire and a four-week course of clomipramine. There were nineteen males and thirty-five females. Sixty-eight per cent of males and 57% of females had their 'sex life' impaired by depressive illness. Coital rate was decreased and depression interfered with performance and satisfaction. Clomipramine therapy seemed to have advantageous and disadvantageous effects. The advantageous effects were probably associated with improvement in depressive illness. There was evidence that clomipramine had an adverse effect sexually in 26% of males and 14% of females. The effect was dose-related in females.

Coital rates and dizygotic twinning.

There is some evidence, mostly of an epidemiological nature, that coital rates may be positively associated with dizygotic twinning. It is suggested that this link is causal, in which case an explanation becomes available for some curious—and hitherto unexplained—features of dizygotic twinning rates by maternal age and legitimacy.

Coital rates and the pill.

Udry and Morris1 suggested that oral contraceptives abolish the depression in coital rates characteristic of the second half of the menstrual cycle in women not using these drugs. They speculate that this may be due to the absence (because ovulation has been suppressed) of a luteal surge of progesterone. I should like to comment first on this putative explanation and second on the support given by Udry and Morris's data for their contention.

The distribution of coitus within the human intermenstruum.

Daily records are the only acceptable basis for determining human coital rates. A re-analysis of such data presented by earlier writers and a study of new data suggest that within the intermenstruum (viz. the days on which there is no bleeding) the rate of coitus is highest immediately after menstruation ceases, declines thereafter and is lowest (within the intermenstruum) just before menstruation recurs.It is not clear whether there is a minor peak around ovulation time, but such a correlation, if it exists, is certainly not very powerful.The major cause of the higher coital rate after menstruation could be abstinence during menstruation and a post-menstrual feeling of release on the part of the woman.The fact that coital rates are largely independent of the time of ovulation might be due to their being largely determined by the male. In any case, it provides evidence for Morris's view that human sexuality has important evolutionary functions other than reproduction.

CYCLE DAY OF INSEMINATION, COITAL RATE, AND SEX RATIO

It is hypothesised that the sex of the conceptus is associated with the cycle day of insemination, male zygotes being formed earlier in the cycle, on the average, than females. Support for this theory comes from three sources: (1) early German data; (2) sex distributions of dizygotic twin pairs; (3) demographic data which suggest that coital rates correlate with sex ratios of the resulting infants.

The Dynamics of Sexual Behavior of College Students

A study of 155 males and 222 females all sophomores and juniors at the University of Colorado revealed a premarital coital rate for women of 41% and a 60% coital rate for men. These figures were replicated in an independent follow-up study. Despite the convergence of sexual experience among college men and women considerable evidence was found that a strong double standard still exists. This was particularly true of males when the woman involved was a sister or potential spouse. Further while males felt their friends approved of premarital intercourse females felt intercourse would be disapproved of by friends family and society. The study also showed that the more physically attractive college women though similar in sexual attitudes and values to her less attractive peers had more petting and coital experience indicating that the greater the opportunity for sexual activity the greater the response.

Seasonality of coitus and seasonality of birth

Seasonal variation of birth rates has been observed in every population in which it has been studied. Many hypotheses have been advanced to account for the variation, including seasonal variation in frequency of coitus. This relationship is known to be true for other primates, but seasonal variation in coital rate has not been previously documented in man.This paper presents over one hundred woman-years of data on coital rates from about .fifty white, mostly well-educated, premenopausal, married, husband-present volunteers. Seasonal fluctuations were seen in coital rates, of about the same magnitude as seasonal variations in the white birth rates reported for New York City, 1962-64; for the United States, 1963; and for the highest socioeconomic quintile census tracts, Baltimore, 1952-56. However, shifting the birth rates back forty weeks to approximate conception dates revealed no association with the observed coital rates.If the pattern presented has great generality, seasonal variations in births cannot be explained by seasonality of coitus.

Contraceptive information and sexual morality

The question of the possible effects of contraceptive information, particularly on the sexual behavior of teen-age females has not been systematically investigated by comparing two matched groups of girls, one of which has been given contraceptive information and the other not. It is, however, an important one in the minds of many people and thus it is imperative to probe this area despite the lack of full empirical evidence. The first area that must be discussed concerns the basic forces involved in decisions to accept and participate in various forms of sexual behavior. How important a role does contraceptive information play in such choices? Historically we have some evidence that bears on this point. We have evidence from Kinsey that the vast increases in female premarital coital rates occurred in the generation born 1900-1909 who were in their maturity in the l920's. We also know that Kinsey found no increase in the proportion of females having premarital coitus in birth decades later than this (Kinsey, 1953, pp. 298-301). This is important to mention, for many people have noted Kinsey's reports of large increases in petting in each birth decade in his sample and thought that the same occurred in coitus. The big break-through in most sexual forms occurred in the 1920's, and since that time, in terms of the proportion participating in coitus, there has been no increase. More recent studies support this position (Ehrmann, 1959; Freedman, 1965). However, attitudes do seem to have changed since the l920's and are more permissive today (Reiss, 1960, Chap. 10). How do these changes in our sexual relations relate to our contraceptive knowledge? Contraceptive information has been available in some form since the earliest days of man (Himes, 1963; Tietze, 1965). The bible mentions coitus interruptus (Genesis 38) and even as modern a method as the skin condom was in use during the eighteenth century. Rubber condoms came in almost immediately after the vulcanization of rubber in the 1840's and the feluale diaphragm came

Value-Behavior Discrepancies Regarding Premarital Coitus in Three Western Cultures

University student responses to questionnaires indicated both higher scores on sexual permissiveness and higher rates of premarital coitus in Denmark as compared with two samples from the United States (though intercultural differences in male coital rates could be explained, at least partially, by differences in age distribution among the samples). Of these latter, Midwestern students showed higher permissiveness scores and higher coital rates than did students in the more restrictive Mormon culture of the Intermountain West. In all three samples, males showed higher permissiveness scores and coital rates than females, though these sex differences were relatively small in the permissive culture (Denmark). In the Danish culture approval of premarital coitus ran ahead of actual practice, whereas in the American cultures the reverse was true-with accompanying feelings of guilt. Certain negative effects from premarital coitus showed up highest in the restrictive American cultures (Midwestern and especially Intermountain), suggesting that the difficulty may be partially the result of value-behavior discrepancies.