On average, women live longer than men – this is true for every country in the world. This fact plays an important role in how the sex ratio changes with age through adulthood. If a man and a woman want to reproduce sexually, they have to engage in sexual intercourse. This involves placing the man's erect penis into the woman's vagina. The vagina rubs and puts pressure on the penis, which makes the man have an orgasm. During his orgasm, the man ejaculates, and his semen flows into the woman. If a sperm in the semen reaches the woman's Fallopian tubes and fuses with an ovum, this causes the woman to become pregnant. A man and woman can also have sexual intercourse for pleasure, without wishing to have a baby. Men and women, and gay couples (two women or two men) can also use their sex organs in other ways for pleasure.

Prenatal sex selection (PSS) relies on two technologies: prenatal sex determination (the ability to determine the sex of a foetus during pregnancy) and selective abortion. Boys are also at higher risk of infectious diseases such as syphilis, malaria, respiratory infections, tetanus and diarrheal diseases. This is more generally true for a broad range of infections, spanning person-to-person, vector-borne, blood-borne, and food and water borne diseases. 23 Over time, prenatal discrimination has increased as both abortions and sex determination technologies have become more readily available. Nonetheless, postnatal discrimination still occurs and has a long history. Infanticide has a long history

Homosexual Reproduction: On Whileaway, geneticists combine two egg cells to create a genetically distinct baby, which one of the mothers then carries to term. Sex hormones may be another key reason for weaker immune systems in males. Males have much higher amounts of testosterone which seem to inhibit two major parts of the immune system – B and T-lymphocytes. 27

In this visualization we look at the case of India and how sex ratios change from the 1st child in a family through to the 2nd, 3rd, 4th, and 5th born children. This is adapted from the Economic Survey 2018 5 and based on data from the DHS and National Family Health Surveys in India. It presents this data in two cases: Whilst we might assume that this dynamic would favour women, they could also suffer negative consequences: Waldron, I. (1983). Sex differences in human mortality: the role of genetic factors. Social Science & Medicine, 17(6), 321-333. Jeannine wishes] that she were someone else so she could watch herself coming down the stairs, the beautiful girl who composes everything around her to harmony.Though it is highly regarded as an important feminist text, the novel is not without its share of controversy. It is also considered to be dated by some, and divides critics and audiences alike. [7] Most of the criticism received by Russ was on the radical feminism the novel is perceived to propagate. [2] The character Jael, implies that the slaughter of men was inevitable and necessary for the feminist utopia. For Jael, violence is the only means through which women can free themselves. [1] Allusions and references [ edit ] Allusions to other works [ edit ] Son preference is most common in countries across East and South Asia, but also in some countries in the Middle East and North Africa. 69 Although there are significant cultural, economic and societal differences between these countries there are important parallels which explain strong preference for a boy.

Old age support: sons within a family are often responsible for supporting parents in illness and old age. 69 Elderly parents often live with married children and overwhelmingly so with their sons. This provides a strong economic incentive for a son for old age support. It's a key differentiating factor between countries with and without strong son preference: in Taiwan, it's rare for parents to live with a married daughter, but in the Philippines (without strong son preference) parents are equally likely to live with the son or daughter. 70

Most of these countries are in Asia. Why is this the case? Is there a biological or environmental difference, or is it the result of discrimination?