爲什麼父親想要男孩而母親喜歡女孩？

That tired truism about wanting only a healthy baby and not caring about gender? Puh-leeze. Women want daughters, and men crave sons, finds research in the journal Open Anthropology.

The results surprised even the researchers, from Queen’s University in Ontario, Canada, who’d surveyed more than 2,000 students, staff and faculty at the college about gender preference in offspring. They’d assumed that respondents would show little or no preference, but they found that — no matter how they worded the question — there was a “significant offspring gender preference” along gender lines.

Respondents answered the following questions:

1. What gender would you prefer your firstborn child to be (or did you hope for if you already have a child)?

2. If you were to have (or do have) more than one child, would you prefer the majority to be male or female?

3. If you were to have only one child, what gender would you prefer it to be?

“Today, offspring gender preference conflicts with the ongoing mission in many nations, especially in Western Europe and North America, to pursue social and political agendas aimed at eliminating all discrimination on the basis of gender,” write the authors.

And yet, it persists. What gives?

Men’s preference for sons is pretty easy to explain in terms of evolution. Males have a greater chance of perpetuating the family genes by fathering far more children than a woman could ever bear. Women’s preference for daughters is more nuanced. Maybe it’s a maternal desire to have a shared experience of pregnancy, or maybe women are subscribing to visions of perceived mom-daughter emotional bonds. Call it a “legacy drive,” say the authors, and consider that modern women are so infused with pride over their social and financial empowerment that they want to share the good life with their girls. “There is currently a tendency in North American society to place a high degree of emphasis on realizing one’s own ‘success’ through the success of one’s children,” write the authors. “The present data suggest that this opportunity for legacy is envisioned for males generally through sons, but for females generally through daughters.”

The study didn’t look at thornier questions of whether would-be parents are so committed to the idea of having a child of the same sex that they would practice gender selection to achieve their dreams. But an editorial published in the current edition of the Canadian Medical Association Journal makes the case that parents shouldn’t learn their baby-to-be’s sex until after 30 weeks of pregnancy when abortions are no longer permitted. Female feticide — aborting girls — isn’t unusual in countries including India and China, but it’s apparently also happening in some ethnic groups in Canada and the US.

“This evil devalues women,” writes Dr. Rajendra Kale, the journal’s interim editor-in-chief. “How can it be curbed? The solution is to postpone the disclosure of medically irrelevant information to women until after about 30 weeks of pregnancy.”

That probably wouldn’t go over well stateside, where pregnant women have become accustomed to learning their baby’s sex courtesy of an ultrasound wand before 20 weeks.

“A pregnant woman being told the sex of the fetus at ultrasonography at a time when an unquestioned abortion is possible is the starting point of female feticide from a health care perspective,” writes Dr. Kale. Although a woman has a right to information about herself that relates to her health and medical care, “the sex of the fetus is medically irrelevant information (except when managing rare sex-linked illnesses) and does not affect care.”還在老生常談“不管性別如何，只要一個健康的寶寶”嗎？呀，別提了！《開放人類學》雜誌（Open Anthropology）近來研究發現女性實際上更喜歡生女孩而男性對兒子情有獨鍾。

這一結果讓研究人員也震驚不已，來自加拿大安大略省（Ontario，Canada）皇后大學（Queen's University）的研究人員們通過對在校2000多名學生，職工和教師進行後代偏好問題的調查，得出這一驚人結論。起初他們臆測，受訪者基本沒有或很少有性別偏好，但是後來發現——無論他們用怎樣的方式提出問題，在性別方面答案總是呈現出“明顯的後代性別偏好選擇”。

受訪者需要回答下述問題：

1. 你希望你的第一個孩子是男是女？（即使你已經有了孩子，你是否考慮過這個問題？）

2. 如果你將至少生育幾個孩子的話，你希望他們大多數是男孩還是女孩？

3. 如果你只打算生一個孩子的話，那麼你更希望是男孩還是女孩？

調查人員記錄道：“如今，子女偏好與許多國家的當下社會任務產生了衝突，這尤其體現在西歐和北美等追求社會和政治議程旨在消除所有基於性別因素導致歧視的國家。”

然而，性別偏好的現象依舊存在。什麼是導致這一切的根源呢？

從進化的角度來看，很容易便能解釋男人對兒子的偏愛。男性往往比女性擁有更多機會來通過養育孩子延續家族基因。女性對女兒的偏愛之情就更爲微妙了，或許是一種母性的期待母女二人能夠分享妊娠的經歷，或者是女性更認同這種稱爲情感紐帶的物質。作者寫道：“將之稱爲遺產的驅使吧”，考慮到現代女性在社會和財政權力方面“掌握大權”並如此沾沾自喜，使得她們想同女兒分享這一美好的生活。對此，作者繼續記錄道：“在北美社會，目前的趨勢是高度強調通過孩子的成功來實現自己的成功之夢，當下的數據也表明遺產繼承一般都由父輩傳至兒子，而母親往往是傳至女兒。”

該項學術研究並沒有關注這一更爲棘手的問題——“準爸爸媽媽”們是否會通過性別選擇手段統一孩子的性別來實現自身的夢想。但是最新一期的《加拿大醫學協會雜誌》上發表的一篇社論表示父母不應當在妊娠30周之內便知曉胎兒的性別情況，這個30周的時間過後便不再允許墮胎行爲的發生。在中國和印度等國家女性墮胎流產胎兒的案例屢見不鮮，但在美國和加拿大某些種族羣體中，也明顯存在着墮胎現象。

雜誌臨時主編拉金德·卡勒（Rajendra Kale）寫道：“墮胎這個惡魔貶低了女性的地位。”“怎樣才能禁止墮胎呢？解決方法便是延期告知時間，在懷孕30周之後再告知當事人這些無關痛癢的具體信息。”

這一提議在美國本土並不會收穫良好效果，在美國，孕婦們在20周之前通過超聲波檢測儀瞭解腹中胎兒的性別已成慣例。

卡勒博士寫道：“從醫療保健的角度來看，孕婦一旦下定決心墮胎時，通過超聲波得知胎兒的性別情況將是執行墮胎手術的起點。”儘管女性有權力知曉自身健康和醫療保健情況，但是“除了能夠檢測到罕見的伴性疾病時，胎兒的性別着實是無關信息，它也不會影響到孕婦的日常護理。”