Scientists are finding that, after all, love really is down to a chemical addiction between people

科學家們發現愛情確實是人與人之間的一種化學成癮現象。

OVER the course of history it has been artists, poets and playwrights who have made the greatest progress in humanity's understanding of love. Romance has seemed as inexplicable as the beauty of a rainbow. But these days scientists are challenging that notion, and they have rather a lot to say about how and why people love each other.

在漫長的歷史長河中，藝術家、詩人和劇作家在人類對于愛的理解上做出了巨大成就。古往今來，愛的浪漫被視為霓虹，美得難以言狀。而最近，科學家們卻向這種觀念發出了挑戰，并且對戀人們如何與為什么相愛做出許多新的解釋。

Is this useful? The scientists think so. For a start, understanding the neurochemical pathways that regulate social attachments may help to deal with defects in people's ability to form relationships. All relationships, whether they are those of parents with their children, spouses with their partners, or workers with their colleagues, rely on an ability to create and maintain social ties. Defects can be disabling, and become apparent as disorders such as autism and schizophrenia—and, indeed, as the serious depression that can result from rejection in love. Research is also shedding light on some of the more extreme forms of sexual behaviour. And, controversially, some utopian fringe groups see such work as the doorway to a future where love is guaranteed because it will be provided chemically, or even genetically engineered from conception.

這真的有用嗎？科學家們確實如是考慮。首先，讓我們先來了解一下可調節社會附屬關系的神經化學路徑, 這有助于我們解決某些缺乏建立人際能力人群的問題。對于所有關系而言——無論是父母與子女間的親情關系、夫妻間的婚姻關系，還是同事間的伙伴關系，全都依賴于一種建立并保持社會性紐帶的能力。這種能力的缺損可使個人喪失行為能力并導致明顯的心理紊亂，如自閉癥和精神分裂癥，正如將戀愛拒之門外可導致嚴重的沮喪一樣。研究者們同樣把目光投向了若干形式更為極端的性行為。有爭議的是, 一些理想化且處于前沿領域的團體視該項工作為通向未來的一道大門。那時愛情將不會有任何風險，因為源于這個概念的化學或基因工程便可能將其變為現實。

The scientific tale of love begins innocently enough, with voles. The prairie vole is a sociable creature, one of the only 3% of mammal species that appear to form monogamous relationships. Mating between prairie voles is a tremendous 24-hour effort. After this, they bond for life. They prefer to spend time with each other, groom each other for hours on end and nest together. They avoid meeting other potential mates. The male becomes an aggressive guard of the female. And when their pups are born, they become affectionate and attentive parents. However, another vole, a close relative called the montane vole, has no interest in partnership beyond one-night-stand sex. What is intriguing is that these vast differences in behaviour are the result of a mere handful of genes. The two vole species are more than 99% alike, genetically.

關于愛情的科學傳說非常無辜地始于田鼠。草原田鼠作為一種社會性生物，它是僅存3%的“一夫一妻制”哺乳動物中的一類。對“戀愛”中的草原田鼠來說，交配是一項耗時24小時的宏偉工程。一旦“結婚”，小倆口便終生相伴，直到天荒地老。“夫妻倆”寧愿在一起共度時光，為彼此梳理毛發，同筑愛巢也不去搞“婚外戀”。平時，“丈夫”是“妻子”好斗的“護花使者”，而幼崽一旦出生，它們又即刻成為摯愛并專一的父母。然而，另一種被稱作山區田鼠的，作為草原田鼠近親，除了一夜情之外，它們對穩定的伴侶關系毫無興趣。令人不解的是這些行為中的巨大差異卻僅僅源于一小撮基因。如就基因而言，這兩個物種超過99％的部分絕無二致。