This week's issue of the Lancet has a series of articles on sexuality and reproductive health. (LiveScience article here)

Here is the summary of Sexual behaviour in context: a global perspective

Research aimed at investigating sexual behaviour and assessing interventions to improve sexual health has increased in recent decades. The resulting data, despite regional differences in quantity and quality, provide a historically unique opportunity to describe patterns of sexual behaviour and their implications for attempts to protect sexual health at the beginning of the 21st century. In this paper we present original analyses of sexual behaviour data from 59 countries for which they were available. The data show substantial diversity in sexual behaviour by region and sex. No universal trend towards earlier sexual intercourse has occurred, but the shift towards later marriage in most countries has led to an increase in premarital sex, the prevalence of which is generally higher in developed countries than in developing countries, and is higher in men than in women. Monogamy is the dominant pattern everywhere, but having had two or more sexual partners in the past year is more common in men than in women, and reported rates are higher in industrialised than in non-industrialised countries. Condom use has increased in prevalence almost everywhere, but rates remain low in many developing countries.

Some of the particulars get quite interesting, especially with the importance of promoting condom use to prevent STDs, as the study shows areas in which STDs are more prevalent aren't associated with greater promiscuity, but less condom use. It also shows that this whole "abstinence until marriage" crap is pointless in countries in which there is gender inequality as the authors found:

Marriage does not reliably safeguard sexual-health status. Married women find negotiation of safer sex and use of condoms for family planning more difficult than do single women. Very early sexual experience within marriage can be coercive and traumatic.

Oh yeah and:

School-based sex education improves awareness of risk and knowledge of risk reduction strategies, increases self-effectiveness and intention to practice safer sex, and delays rather than hastens the onset of sexual activity.

This is really a must-read, and it just pisses me off that much more that we know how to decrease STD transmission and teen pregnancy, but insist on using abstinence education which simply is ineffective, and, especially in poorer countries or countries with greater gender inequality, it is just irresponsible.