I get a kick out of you 我覺得你真帶勁兒
Scientists are finding that, after all, love really is down to a chemical addiction between people.
科學(xué)家們發(fā)現(xiàn)愛情確實是人與人之間的一種化學(xué)成癮現(xiàn)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(shù)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(xué)家們卻向這種觀念發(fā)出了挑戰(zhàn)，并且對戀人們?nèi)绾闻c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(xué)家們確實如是考慮。首先，讓我們先來了解一下可調(diào)節(jié)社會附屬關(guān)系的神經(jīng)化學(xué)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(guān)系而言——無論是父母與子女間的親情關(guān)系、夫妻間的婚姻關(guān)系，還是同事間的伙伴關(guān)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(dǎo)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(dǎo)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(lǐng)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(fēng)險，因為源于這個概念的化學(xué)或基因工程便可能將其變?yōu)楝F(xiàn)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(guān)于愛情的科學(xué)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(jié)婚”，小倆口便終生相伴，直到天荒地老?！胺蚱迋z”寧愿在一起共度時光，為彼此梳理毛發(fā)，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(qū)田鼠的，作為草原田鼠近親，除了一夜情之外，它們對穩(wěn)定的伴侶關(guān)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。
Why do voles fall in love？ 為什么田鼠會墜入愛河？
The details of what is going on—the vole story, as it were—is a fascinating one. When prairie voles have sex, two hormones called oxytocin and vasopressin are released. If the release of these hormones is blocked, prairie-voles' sex becomes a fleeting affair, like that normally enjoyed by their rakish montane cousins. Conversely, if prairie voles are given an injection of the hormones, but prevented from having sex, they will still form a preference for their chosen partner. In other words, researchers can make prairie voles fall in love—or whatever the vole equivalent of this is—with an injection.
像往常一樣，最讓人著魔的是田鼠愛情故事的進展細節(jié)。當(dāng)草原田鼠性交時，其體內(nèi)會釋放兩種稱作催產(chǎn)素和抗利尿激素的荷爾蒙。如果這些荷爾蒙的釋放被阻斷，草原田鼠的性生活便成了短暫的艷遇，它們就會像生性放蕩的山區(qū)堂兄那樣去盡享受風(fēng)流韻事。 相反，如果給草原田鼠注射以上荷爾蒙，雖然阻止它們性交，它們依然會鐘情于已選擇的伴侶。換句話說, 不過就一劑注射，研究者們便能讓草原田鼠落入情網(wǎng)，不管草原田鼠的感覺如何，反正它們會產(chǎn)生與愛相類似的神經(jīng)反應(yīng)。
A clue to what is happening—and how these results might bear on the human condition—was found when this magic juice was given to the montane vole： it made no difference. It turns out that the faithful prairie vole has receptors for oxytocin and vasopressin in brain regions associated with reward and reinforcement, whereas the montane vole does not. The question is, do humans （another species in the 3% of allegedly monogamous mammals） have brains similar to prairie voles？
研究者找到一條與正在發(fā)生情形相關(guān)的線索，這一線索與如何使上述結(jié)果作用于人類有關(guān)。線索的結(jié)論是：當(dāng)把這一魔術(shù)般的汁液注入山區(qū)田鼠體內(nèi)，其反應(yīng)與草原田鼠如出一轍。這就證實了，在忠誠的草原田鼠大腦內(nèi)，與獎賞與強化相關(guān)聯(lián)的區(qū)域中，具有一種催產(chǎn)素和抗利尿激素的荷爾蒙受體, 然而山區(qū)田鼠卻沒有。 問題是： 人類——據(jù)稱是3%實行一夫一妻制的哺乳動物中的另一物種，是否也具有和草原田鼠相似的大腦結(jié)構(gòu)？
To answer that question you need to dig a little deeper. As Larry Young, a researcher into social attachment at Emory University, in Atlanta, Georgia, explains, the brain has a reward system designed to make voles （and people and other animals） do what they ought to. Without it, they might forget to eat, drink and have sex—with disastrous results. That animals continue to do these things is because they make them feel good. And they feel good because of the release of a chemical called dopamine into the brain. Sure enough, when a female prairie vole mates, there is a 50% increase in the level of dopamine in the reward centre of her brain.
為對上述疑惑刨根問底，就需要“挖”得更深一些。一位來自佐治亞州，亞特蘭大Emory大學(xué)，研究社會附屬關(guān)系的學(xué)者Larry Yong，他對此的解釋是，田鼠（以及人類和其他動物）的大腦內(nèi)具有一套獎賞系統(tǒng)用以鼓勵它（他）們?nèi)プ錾飸?yīng)該完成的行為。如若不然，動物將忘記進食，飲水和性行為，從而招致災(zāi)難性的后果。動物們不斷重復(fù)這些行為是因為那使它們感到快樂。這種快感是一種稱作多巴胺的化學(xué)物質(zhì)在大腦中的釋放使然。當(dāng)雌性草原田鼠交配時，在大腦獎賞系統(tǒng)中樞，多巴胺水平會有50%的上升，而這已完全足夠讓這些“女士”們產(chǎn)生上面提到的那種快感。
Similarly, when a male rat has sex it feels good to him because of the dopamine. He learns that sex is enjoyable, and seeks out more of it based on how it happened the first time. But, in contrast to the prairie vole, at no time do rats learn to associate sex with a particular female. Rats are not monogamous.
與草原田鼠近似，雄性家鼠性交時，因多巴胺分泌同樣會感到快樂。當(dāng)它體驗到性讓它感到愉悅，便會參照初次經(jīng)歷去搜尋更多機會。但與草原田鼠相反，家鼠決不會學(xué)習(xí)把性與某個特定的雌性個體關(guān)聯(lián)起來。畢竟家鼠不是“一夫一妻制”的哺乳動物。
This is where the vasopressin and oxytocin come in. They are involved in parts of the brain that help to pick out the salient features used to identify individuals. If the gene for oxytocin is knocked out of a mouse before birth, that mouse will become a social amnesiac and have no memory of the other mice it meets. The same is true if the vasopressin gene is knocked out.
抗利尿激素和催產(chǎn)素就是從這里進入這個科學(xué)傳說的。它們參與了大腦一些部分的工作，以幫助選出用于辨別個體的顯著特征。 如果在老鼠出生前，DNA中的抗利尿激素基因即被剔除, 那只老鼠將會成為一個社會性失憶個體，它也不會對遇到的其他老鼠留下任何印象。如果催產(chǎn)素基因缺損，以上命題同樣成立。
The salient feature in this case is odour. Rats, mice and voles recognise each other by smell. Christie Fowler and her colleagues at Florida State University have found that exposure to the opposite sex generates new nerve cells in the brains of prairie voles—in particular in areas important to olfactory memory. Could it be that prairie voles form an olfactory “image” of their partners—the rodent equivalent of remembering a personality—and this becomes linked with pleasure？
這里的顯著特征是氣味。耗子、老鼠和野鼠靠嗅覺區(qū)分彼此。Christie Fowler和她的同事在佛羅里達州大學(xué)的研究中發(fā)現(xiàn)，把草原田鼠暴露給異性可使其大腦產(chǎn)生新的神經(jīng)細胞——在對嗅覺記憶至關(guān)重要的一些區(qū)域尤其如此。人類是靠個性特征來記住某一個人的。那么草原田鼠會構(gòu)造一個嗅覺“形像”去記住伴侶嗎？這與性愉悅是否存在關(guān)聯(lián)呢？
Dr Young and his colleagues suggest this idea in an article published last month in the Journal of Comparative Neurology. They argue that prairie voles become addicted to each other through a process of sexual imprinting mediated by odour. Furthermore, they suggest that the reward mechanism involved in this addiction has probably evolved in a similar way in other monogamous animals, humans included, to regulate pair-bonding in them as well.
Young博士和他的同事在上個月《比較神經(jīng)學(xué)期刊》的文章中提到了這種想法。他們認為草原田鼠通過一個由氣味做媒介的性烙印過程使配偶彼此沉溺于對方。此外，他們還提到，與這彼此沉溺上癮相關(guān)的獎賞機制在其他的一夫一妻制動物（包括人類）生理系統(tǒng)中，或許也進化成了相似的方式，以規(guī)范他們的配偶聯(lián)結(jié)關(guān)系。
You might as well face it …… 你或許也會面對它……
Sex stimulates the release of vasopressin and oxytocin in people, as well as voles, though the role of these hormones in the human brain is not yet well understood. But while it is unlikely that people have a mental, smell-based map of their partners in the way that voles do, there are strong hints that the hormone pair have something to reveal about the nature of human love： among those of Man's fellow primates that have been studied, monogamous marmosets have higher levels of vasopressin bound in the reward centres of their brains than do non-monogamous rhesus macaques.
雖然抗利尿激素和催產(chǎn)素在人腦內(nèi)的角色仍未被透徹了解，但與田鼠一樣，人體在受到性刺激時也會釋放這些荷爾蒙。盡管與田鼠不一樣，人類不太可能有一張基于嗅覺的神經(jīng)系統(tǒng)伴侶圖譜，但若干線索已有力說明，這兩種荷爾蒙能揭示一些人類戀愛的本質(zhì)∶在已被研究過的人類靈長目同伴之中，一夫一妻制小長尾猴的大腦獎賞中樞系統(tǒng)中，抗利尿激素水平較非一夫一妻制的恒河短尾猿高。
Other approaches are also shedding light on the question. In 2000, Andreas Bartels and Semir Zeki of University College, London, located the areas of the brain activated by romantic love. They took students who said they were madly in love, put them into a brain scanner, and looked at their patterns of brain activity.
其他方法也正在為人們尋找這些問題的謎底。2000 年，來自倫敦市大學(xué)學(xué)院的Andreas Bartels和Semir Zeki定位出了能被浪漫愛情激活的大腦區(qū)域。兩位學(xué)者選擇自稱正在熱戀的學(xué)生作為測試目標，利用腦掃描儀對他們的大腦活動模式進行觀測。
The results were surprising. For a start, a relatively small area of the human brain is active in love, compared with that involved in, say, ordinary friendship. “It is fascinating to reflect”, the pair conclude, “that the face that launched a thousand ships should have done so through such a limited expanse of cortex.” The second surprise was that the brain areas active in love are different from the areas activated in other emotional states, such as fear and anger. Parts of the brain that are love-bitten include the one responsible for gut feelings, and the ones which generate the euphoria induced by drugs such as cocaine. So the brains of people deeply in love do not look like those of people experiencing strong emotions, but instead like those of people snorting coke. Love, in other words, uses the neural mechanisms that are activated during the process of addiction. “We are literally addicted to love,” Dr Young observes. Like the prairie voles.
令人驚訝的是：首先，人腦參與到戀愛的活動區(qū)域，較之其他感情（如普通友誼），相對要比較小些?！耙俗⒁獾氖?，結(jié)果顯示，”兩位學(xué)者推斷說，“美麗的面容是通過控制一個有限區(qū)域的大腦皮層來實現(xiàn)‘一顧傾人城，再顧傾人國’的?！?第二個驚奇之處是，大腦內(nèi)因戀愛而活躍的區(qū)域不同于因其他情緒而活躍的區(qū)域，例如，恐懼和憤怒。 被戀愛“咬住”的那部份大腦還包括負責(zé)內(nèi)臟感覺和因可卡因等毒品生成快感的區(qū)域。因此，因此，深墜愛河的戀人們的大腦，并非類同于經(jīng)歷強烈情緒波動的人，倒更接近那些鼻吸可卡因的癮君子。換句話說，愛情使用的是在成癮過程中被激活的神經(jīng)機制。“嚴格地講, 我們成癮于愛情，”Young博士評述道，“就如同草原田鼠”。
It seems possible, then, that animals which form strong social bonds do so because of the location of their receptors for vasopressin and oxytocin. Evolution acts on the distribution of these receptors to generate social or non-social versions of a vole. The more receptors located in regions associated with reward, the more rewarding social interactions become. Social groups, and society itself, rely ultimately on these receptors. But for evolution to be able to act, there must be individual variation between mice, and between men. And this has interesting implications.
那么看起來，能形成穩(wěn)固社會聯(lián)結(jié)的動物之所以愿意建立彼此間的伙伴關(guān)系，可能是由它們的抗利尿激素和催產(chǎn)素受體在大腦中的位置所決定。生物進化作用于以上受體在大腦的分布，而產(chǎn)生了社會性或非社會性不同版本的田鼠。位于獎賞機制有關(guān)區(qū)域的受體越多，對個體而言, 社會互動就更具有回報性。動物的社會性團體，乃至整個社會本身都最終依賴于這些受體。但要使進化真能發(fā)生效力，在鼠之鼠之間以及人與人之間，一定存在個體變異。這一論述還有引人入勝的推論。
Last year, Steven Phelps, who works at Emory with Dr Young, found great diversity in the distribution of vasopressin receptors between individual prairie voles. He suggests that this variation contributes to individual differences in social behaviour—in other words, some voles will be more faithful than others. Meanwhile, Dr Young says that he and his colleagues have found a lot of variation in the vasopressin-receptor gene in humans. “We may be able to do things like look at their gene sequence, look at their promoter sequence, to genotype people and correlate that with their fidelity,” he muses.
在Emory大學(xué)與Young博士一同工作的Steven Phelps去年發(fā)現(xiàn)，草原田鼠各個體間抗利尿激素受體的腦內(nèi)分布，存在著很大的差異。他提出，正是這一變異導(dǎo)致了社會行為的個體差異，換句話說，一些田鼠將會比另一些更加忠誠。同時，Young博士說他和同事已經(jīng)發(fā)現(xiàn)人類抗利尿激素受體基因的許多變異。“我們或許能夠做些類似于察看人們的基因序列，察看他們的啟動序列等工作，在此基礎(chǔ)上對人們進行基因型分類, 并把分類結(jié)果與他們的忠誠度關(guān)聯(lián)起來”，Young博士作如是想。
It has already proved possible to tinker with this genetic inheritance, with startling results. Scientists can increase the expression of the relevant receptors in prairie voles, and thus strengthen the animals' ability to attach to partners. And in 1999, Dr Young led a team that took the prairie-vole receptor gene and inserted it into an ordinary （and therefore promiscuous） mouse. The transgenic mouse thus created was much more sociable to its mate.
事實已經(jīng)證明可能對這種基因遺傳進行修補，并產(chǎn)生了令人吃驚的結(jié)果?？茖W(xué)家能增加草原田鼠相關(guān)受體的表達，以加強動物對同伴的依附能力。而且在 1999 年，Young博士帶領(lǐng)了一只研究隊伍，他們將草原田鼠的受體基因插入到一只平常（因此成為雜亂的） 老鼠的體內(nèi)，由此產(chǎn)生的轉(zhuǎn)基因鼠對它的配偶表現(xiàn)得更為友善。
Love, love me do 愛我，真心地愛我
Scanning the brains of people in love is also helping to refine science's grasp of love's various forms. Helen Fisher, a researcher at Rutgers University, and the author of a new book on love*, suggests it comes in three flavours： lust, romantic love and long-term attachment. There is some overlap but, in essence, these are separate phenomena, with their own emotional and motivational systems, and accompanying chemicals. These systems have evolved to enable, respectively, mating, pair-bonding and parenting.
對戀愛中人們大腦的掃描，也有助于使科學(xué)對各種形式愛情的領(lǐng)會變得更為精確。Rutgers 大學(xué)的一位研究人員Helen Fisher，同時是一本關(guān)于愛情的新書作者，她提出，愛會以三種滋味出現(xiàn)：欲望，浪漫的戀愛和長期的附屬關(guān)系。三種滋味的愛情雖有一些重疊，但本質(zhì)上是截然不同的現(xiàn)象，并且具有各自的情緒和激發(fā)系統(tǒng)，以及相伴的體內(nèi)化學(xué)物質(zhì)。這些系統(tǒng)通過進化后以分別讓交配，伴侶聯(lián)接和養(yǎng)育子女成為可能。
Lust, of course, involves a craving for sex. Jim Pfaus, a psychologist at Concordia University, in Montreal, says the aftermath of lustful sex is similar to the state induced by taking opiates. A heady mix of chemical changes occurs, including increases in the levels of serotonin, oxytocin, vasopressin and endogenous opioids （the body's natural equivalent of heroin）. “This may serve many functions, to relax the body, induce pleasure and satiety, and perhaps induce bonding to the very features that one has just experienced all this with”, says Dr Pfaus.
首先當(dāng)然是欲望，包括對性的強烈渴求。蒙特利爾Concordia大學(xué)的一位心理學(xué)家，Jim Pfaus說道，貪欲的性行為其結(jié)果和使用鴉片引起的狀況頗相類似：一種令人興奮的混合化學(xué)變化，包括血液復(fù)合胺（5羥色氨），催產(chǎn)素，抗利尿激素和內(nèi)非肽（身體內(nèi)的海洛英的天然同等物） 的水平升高?！斑@可能提供許多功能，如放松身體，產(chǎn)生快樂和滿足感, 也可能導(dǎo)致把某些特征與剛才的全部經(jīng)歷聯(lián)結(jié)起來，”Pfaus博士補充道。
Then there is attraction, or the state of being in love （what is sometimes known as romantic or obsessive love）. This is a refinement of mere lust that allows people to home in on a particular mate. This state is characterised by feelings of exhilaration, and intrusive, obsessive thoughts about the object of one's affection. Some researchers suggest this mental state might share neurochemical characteristics with the manic phase of manic depression. Dr Fisher's work, however, suggests that the actual behavioural patterns of those in love—such as attempting to evoke reciprocal responses in one's loved one—resemble obsessive compulsive disorder （OCD）.
接下來便是兩性吸引，雙方處于相愛的狀態(tài) （就是我們所知的浪漫的、或強迫性的戀愛）。這是純粹的欲望的升華，它使人們總能回到某個特定配偶身邊。這種狀態(tài)的特征，是興奮感和對情感對象打擾式的和強迫性的思戀。一些研究員提到，這一心理狀態(tài)可能和狂躁狀態(tài)的躁郁癥有相同的神經(jīng)化學(xué)特征。Fisher博士的工作揭示了戀愛人群真實的行為模式，比如：試圖喚起被愛者的報答——類似于強迫性混亂癥（OCD）。
That raises the question of whether it is possible to “treat” this romantic state clinically, as can be done with OCD. The parents of any love-besotted teenager might want to know the answer to that. Dr Fisher suggests it might, indeed, be possible to inhibit feelings of romantic love, but only at its early stages. OCD is characterised by low levels of a chemical called serotonin. Drugs such as Prozac work by keeping serotonin hanging around in the brain for longer than normal, so they might stave off romantic feelings. （This also means that people taking anti-depressants may be jeopardising their ability to fall in love.） But once romantic love begins in earnest, it is one of the strongest drives on Earth. Dr Fisher says it seems to be more powerful than hunger. A little serotonin would be unlikely to stifle it.
這又產(chǎn)生一個問題，即是否可能和處理OCD一樣，用病理學(xué)方式來“處治”這種浪漫狀態(tài)。任何沉醉于愛情的青少年，他們的父母可能都想知道相應(yīng)的答案。Fisher博士提出，抑制浪漫愛情的可能性確實存在，但只能是在感情發(fā)展的最初階段。OCD的特征，是血液中一種叫血液復(fù)合胺（5羥色氨）的含量較低。如果Prozac等藥物讓血液中的復(fù)合氨在大腦中停留得比正常時間更久，這些藥品就可能阻止浪漫感覺的出現(xiàn)。（這也意味著服用抗抑郁藥物的人們可能正在危及他們彼此相愛能力。）真摯浪漫的愛情一旦開始，它就成為了地球上大的動力之一。Fisher博士說，這種欲望比食欲強大得多，一點兒血液中的復(fù)合氨不太可能扼殺心中如此強烈的情感。
Wonderful though it is, romantic love is unstable—not a good basis for child-rearing. But the final stage of love, long-term attachment, allows parents to co-operate in raising children. This state, says Dr Fisher, is characterised by feelings of calm, security, social comfort and emotional union.
盡管浪漫的愛情如此奇妙，但它卻并不穩(wěn)定——這絕非養(yǎng)兒育女的良好基礎(chǔ)。而愛情的最后階段，即長期的附屬關(guān)系，卻使父母在養(yǎng)育孩子方面得以精誠合作——這種狀態(tài)，F(xiàn)isher博士認為，它的特征恰恰是平穩(wěn)感、安全感、社會性的慰籍以及情感的結(jié)合。
Because they are independent, these three systems can work simultaneously—with dangerous results. As Dr Fisher explains, “you can feel deep attachment for a long-term spouse, while you feel romantic love for someone else, while you feel the sex drive in situations unrelated to either partner.” This independence means it is possible to love more than one person at a time, a situation that leads to jealousy, adultery and divorce—though also to the possibilities of promiscuity and polygamy, with the likelihood of extra children, and thus a bigger stake in the genetic future, that those behaviours bring. As Dr Fisher observes, “We were not built to be happy but to reproduce.”
因為三個階段的系統(tǒng)彼此獨立，所以他們可能同時工作而導(dǎo)致危險的后果。如Fisher博士解釋的那樣，“你可能對長期配偶有深深的附屬感，同時你又因另一人而感受到浪漫的愛情，其間，你又由于第三位異性而產(chǎn)生性驅(qū)動力。”這種獨立性意味著你可能同時愛上多個異性而導(dǎo)致妒忌、私通和離婚——盡管也有可能是亂交、一夫多妻、和隨之而來的額外生育，即最終一個更大的預(yù)期基因賭注。正如Fisher博士所述，“我們不是為快樂卻是為了生殖而被創(chuàng)造的。”
The stages of love vary somewhat between the sexes. Lust, for example, is aroused more easily in men by visual stimuli than is the case for women. This is probably why visual pornography is more popular with men. And although both men and women express romantic love with the same intensity, and are attracted to partners who are dependable, kind, healthy, smart and educated, there are some notable differences in their choices. Men are more attracted to youth and beauty, while women are more attracted to money, education and position. When an older, ugly man is seen walking down the road arm-in-arm with a young and beautiful woman, most people assume the man is rich or powerful.
愛情的各階段在性別之間略有差別。例如，與女性相比，男性的欲望更容易被視覺刺激喚醒。這或許就是為什么視覺色情對男性而言更加流行。雖然男人和女人用同樣的強度表達浪漫的愛情，也同樣會被可靠、和藹、健康、聰明和有教養(yǎng)的伴侶所吸引，但不同性別在選擇配偶時還是有著一些顯著的不同。男性更易被年輕和美貌所吸引，而女性更多會青睞于金錢、教育和地位。當(dāng)人們看到蒼老而丑陋的男人手挽著年輕美麗的女子漫步道旁，大多數(shù)都會設(shè)想此公不是腰纏萬貫，便有大權(quán)在握。
These foolish things 這些愚蠢的玩意兒
Of course, love is about more than just genes. Cultural and social factors, and learning, play big roles. Who and how a person has loved in the past are important determinants of his （or her） capacity to fall in love at any given moment in the future. This is because animals—people included—learn from their sexual and social experiences. Arousal comes naturally. But long-term success in mating requires a change from being naive about this state to knowing the precise factors that lead from arousal to the rewards of sex, love and attachment. For some humans, this may involve flowers, chocolate and sweet words. But these things are learnt.
當(dāng)然，愛情不止與基因有關(guān)。文化社會因素和后天的學(xué)習(xí)在其中也扮演著重要的角色。一個人曾經(jīng)愛過誰？如何愛過？對他（她）將來任何時刻的相愛能力都是決定性的因素，因為動物（包括人類）能從他們的性和社會經(jīng)驗中進行學(xué)習(xí)。性喚醒可本能地產(chǎn)生，但長期而成功的配偶關(guān)系，卻需要一個對愛情各種精確因素從無知到熟悉的改變過程，這個過程包括由性喚醒而導(dǎo)致性行為、愛和附屬關(guān)系產(chǎn)生對大腦的獎賞。對于一些人來說，這可能包括鮮花、巧克力和甜言蜜語：這些都是可以學(xué)會的。
If humans become conditioned by their experiences, this may be the reason why some people tend to date the same “type” of partner over and over again. Researchers think humans develop a “l(fā)ove map” as they grow up—a blueprint that contains the many things that they have learnt are attractive. This inner scorecard is something that people use to rate the suitability of mates. Yet the idea that humans are actually born with a particular type of “soul mate” wired into their desires is wrong. Research on the choices of partner made by identical twins suggests that the development of love maps takes time, and has a strong random component.
人類常常會囿于自身的經(jīng)驗，因此某些人總喜歡一再地和相同“類型”伴侶約會。研究人員認為，隨著人們年齡的增長，他們會在大腦內(nèi)發(fā)展一個“愛情地圖”——一個包含許多人們已經(jīng)熟悉的、魅力事物的藍圖。這個內(nèi)部記分卡是人們用于評價配偶適合度的依據(jù)。認為特定類型的“精神伴侶”與欲望的內(nèi)在聯(lián)系是與生俱來，這種想法是錯誤的。對同卵雙胞胎擇偶的研究表明，愛情地圖的發(fā)展需要時間，而且有很強的隨機成份。
Work on rats is leading researchers such as Dr Pfaus to wonder whether the template of features found attractive by an individual is formed during a critical period of sexual-behaviour development. He says that even in animals that are not supposed to pair-bond, such as rats, these features may get fixed with the experience of sexual reward. Rats can be conditioned to prefer particular types of partner—for example by pairing sexual reward with some kind of cue, such as lemon-scented members of the opposite sex. This work may help the understanding of unusual sexual preferences. Human fetishes, for example, develop early, and are almost impossible to change. The fetishist connects objects such as feet, shoes, stuffed toys and even balloons, that have a visual association with childhood sexual experiences, to sexual gratification.
針對家鼠的研究工作使Pfaus博士等研究人員力圖查明：具有異性魅力的特征模板，是不是在性行為發(fā)展的關(guān)鍵時期形成的？他認為，即使在沒有伴侶連接習(xí)性的動物當(dāng)中——如家鼠——這些特征仍可能通過性獎賞的經(jīng)驗固定下來。家鼠能條件反射地偏愛特別類型的伴侶。舉例來說，性獎賞同時伴隨著某種提示條件，比如具有檸檬氣息的異性。這項工作也許有助于對異常的性偏愛的理解。例如，人類的戀物情結(jié)發(fā)展于早期，而且?guī)缀跏遣豢筛淖?。戀物癖者會把童年時期在視覺上和性經(jīng)驗關(guān)聯(lián)的物體與性滿足連接起來，諸如腳、鞋子、布玩具甚至氣球等。
So love, in all its glory, is just, it seems, a chemical state with genetic roots and environmental influences. But all this work leads to other questions. If scientists can make a more sociable mouse, might it be possible to create a more sociable human？ And what about a more loving one？ A few people even think that “paradise-engineering”, dedicated to abolishing the “biological substrates of human suffering”, is rather a good idea.
因此，關(guān)于愛的所有光彩之處，看上去只不過是具有遺傳基礎(chǔ)和受環(huán)境影響的一種化學(xué)狀態(tài)。與此相關(guān)，這兒涉及的一切還將導(dǎo)致更多其他的問題。如果科學(xué)家能制造一只社會性更強的老鼠，那么他們是否可能產(chǎn)生一個社會性更強的人呢？創(chuàng)造一個更惹人喜愛的人，其結(jié)果又將如何？一些人甚至認為致力于廢除“人類受難的生物學(xué)基體”的“天堂工程”，是一個非常不錯的主意。
As time goes by 時光流逝
Progress in predicting the outcome of relationships, and information about the genetic roots of fidelity, might also make proposing marriage more like a job application—with associated medical, genetic and psychological checks. If it were reliable enough, would insurers cover you for divorce？ And as brain scanners become cheaper and more widely available, they might go from being research tools to something that anyone could use to find out how well they were loved. Will the future bring answers to questions such as： Does your partner really love you？ Is your husband lusting after the au pair？
通過彼此關(guān)聯(lián)的醫(yī)學(xué)、遺傳基因和心理學(xué)的檢查，預(yù)測人際關(guān)系最終結(jié)果的研究進展和關(guān)于忠誠度的遺傳基礎(chǔ)信息，能使求婚變得更像工作申請。如果這個結(jié)論足夠可信，保險公司會為你的婚姻投保嗎？當(dāng)腦掃描儀變得更便宜更普及，它能由研究工具變成任何人都可以用于發(fā)現(xiàn)他們被愛到何種程度的手段嗎？未來會不會就如下問題為人類找到答案：你的伴侶是否真的愛你？ 你的丈夫是否正對來家打工的留學(xué)女生暗送秋波？
And then there are drugs. Despite Dr Fisher's reservations, might they also help people to fall in love, or perhaps fix broken relationships？ Probably not. Dr Pfaus says that drugs may enhance portions of the “l(fā)ove experience” but fall short of doing the whole job because of their specificity. And if a couple fall out of love, drugs are unlikely to help either. Dr Fisher does not believe that the brain could overlook distaste for someone—even if a couple in trouble could inject themselves with huge amounts of dopamine.
接下來當(dāng)然會有相應(yīng)的藥物。盡管Fisher博士對此有所保留。我們還是想問：藥物是否可能幫助人們墜入愛河，或者破鏡重圓？ 或許不能完全做到，但卻可能部分地提高“戀愛體驗”。對此另一位學(xué)者Pfaus博士如是說：藥物達不到整體提高的效果，因為藥畢竟是藥，這就是它的特殊性。如果一對夫婦不再相愛，藥物多半無能為力。Fisher博士不相信大腦可以忽略對某人的厭惡——即使對婚姻危機中的夫婦大量注射的多巴氨，也于事無補。
However, she does think that administering serotonin can help someone get over a bad love affair faster. She also suggests it is possible to trick the brain into feeling romantic love in a long-term relationship by doing novel things with your partner. Any arousing activity drives up the level of dopamine and can therefore trigger feelings of romance as a side effect. This is why holidays can rekindle passion. Romantics, of course, have always known that love is a special sort of chemistry. Scientists are now beginning to show how true this is.
然而，她確實認為調(diào)控血液復(fù)合胺（5羥色氨）水平能更快地幫助人走出戀愛的低谷。她同時建議和你的伴侶做一些新鮮事，這樣可能哄騙大腦在長期兩性關(guān)系中依然能感覺到愛情的甜美。任何喚醒活動都會提高多巴胺的水平而引發(fā)浪漫的感受。這就是為什么假日能重新點燃激情的原因所在。當(dāng)然，愛情浪漫主義者總是認為愛情是一種特殊的化學(xué)，而正是科學(xué)家們，現(xiàn)在開始展示出了這一看法是如何的千真萬確。
Scientists are finding that, after all, love really is down to a chemical addiction between people.
科學(xué)家們發(fā)現(xiàn)愛情確實是人與人之間的一種化學(xué)成癮現(xiàn)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(shù)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(xué)家們卻向這種觀念發(fā)出了挑戰(zhàn)，并且對戀人們?nèi)绾闻c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(xué)家們確實如是考慮。首先，讓我們先來了解一下可調(diào)節(jié)社會附屬關(guān)系的神經(jīng)化學(xué)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(guān)系而言——無論是父母與子女間的親情關(guān)系、夫妻間的婚姻關(guān)系，還是同事間的伙伴關(guān)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(dǎo)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(dǎo)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(lǐng)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(fēng)險，因為源于這個概念的化學(xué)或基因工程便可能將其變?yōu)楝F(xiàn)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(guān)于愛情的科學(xué)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(jié)婚”，小倆口便終生相伴，直到天荒地老?！胺蚱迋z”寧愿在一起共度時光，為彼此梳理毛發(fā)，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(qū)田鼠的，作為草原田鼠近親，除了一夜情之外，它們對穩(wěn)定的伴侶關(guān)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。
Why do voles fall in love？ 為什么田鼠會墜入愛河？
The details of what is going on—the vole story, as it were—is a fascinating one. When prairie voles have sex, two hormones called oxytocin and vasopressin are released. If the release of these hormones is blocked, prairie-voles' sex becomes a fleeting affair, like that normally enjoyed by their rakish montane cousins. Conversely, if prairie voles are given an injection of the hormones, but prevented from having sex, they will still form a preference for their chosen partner. In other words, researchers can make prairie voles fall in love—or whatever the vole equivalent of this is—with an injection.
像往常一樣，最讓人著魔的是田鼠愛情故事的進展細節(jié)。當(dāng)草原田鼠性交時，其體內(nèi)會釋放兩種稱作催產(chǎn)素和抗利尿激素的荷爾蒙。如果這些荷爾蒙的釋放被阻斷，草原田鼠的性生活便成了短暫的艷遇，它們就會像生性放蕩的山區(qū)堂兄那樣去盡享受風(fēng)流韻事。 相反，如果給草原田鼠注射以上荷爾蒙，雖然阻止它們性交，它們依然會鐘情于已選擇的伴侶。換句話說, 不過就一劑注射，研究者們便能讓草原田鼠落入情網(wǎng)，不管草原田鼠的感覺如何，反正它們會產(chǎn)生與愛相類似的神經(jīng)反應(yīng)。
A clue to what is happening—and how these results might bear on the human condition—was found when this magic juice was given to the montane vole： it made no difference. It turns out that the faithful prairie vole has receptors for oxytocin and vasopressin in brain regions associated with reward and reinforcement, whereas the montane vole does not. The question is, do humans （another species in the 3% of allegedly monogamous mammals） have brains similar to prairie voles？
研究者找到一條與正在發(fā)生情形相關(guān)的線索，這一線索與如何使上述結(jié)果作用于人類有關(guān)。線索的結(jié)論是：當(dāng)把這一魔術(shù)般的汁液注入山區(qū)田鼠體內(nèi)，其反應(yīng)與草原田鼠如出一轍。這就證實了，在忠誠的草原田鼠大腦內(nèi)，與獎賞與強化相關(guān)聯(lián)的區(qū)域中，具有一種催產(chǎn)素和抗利尿激素的荷爾蒙受體, 然而山區(qū)田鼠卻沒有。 問題是： 人類——據(jù)稱是3%實行一夫一妻制的哺乳動物中的另一物種，是否也具有和草原田鼠相似的大腦結(jié)構(gòu)？
To answer that question you need to dig a little deeper. As Larry Young, a researcher into social attachment at Emory University, in Atlanta, Georgia, explains, the brain has a reward system designed to make voles （and people and other animals） do what they ought to. Without it, they might forget to eat, drink and have sex—with disastrous results. That animals continue to do these things is because they make them feel good. And they feel good because of the release of a chemical called dopamine into the brain. Sure enough, when a female prairie vole mates, there is a 50% increase in the level of dopamine in the reward centre of her brain.
為對上述疑惑刨根問底，就需要“挖”得更深一些。一位來自佐治亞州，亞特蘭大Emory大學(xué)，研究社會附屬關(guān)系的學(xué)者Larry Yong，他對此的解釋是，田鼠（以及人類和其他動物）的大腦內(nèi)具有一套獎賞系統(tǒng)用以鼓勵它（他）們?nèi)プ錾飸?yīng)該完成的行為。如若不然，動物將忘記進食，飲水和性行為，從而招致災(zāi)難性的后果。動物們不斷重復(fù)這些行為是因為那使它們感到快樂。這種快感是一種稱作多巴胺的化學(xué)物質(zhì)在大腦中的釋放使然。當(dāng)雌性草原田鼠交配時，在大腦獎賞系統(tǒng)中樞，多巴胺水平會有50%的上升，而這已完全足夠讓這些“女士”們產(chǎn)生上面提到的那種快感。
Similarly, when a male rat has sex it feels good to him because of the dopamine. He learns that sex is enjoyable, and seeks out more of it based on how it happened the first time. But, in contrast to the prairie vole, at no time do rats learn to associate sex with a particular female. Rats are not monogamous.
與草原田鼠近似，雄性家鼠性交時，因多巴胺分泌同樣會感到快樂。當(dāng)它體驗到性讓它感到愉悅，便會參照初次經(jīng)歷去搜尋更多機會。但與草原田鼠相反，家鼠決不會學(xué)習(xí)把性與某個特定的雌性個體關(guān)聯(lián)起來。畢竟家鼠不是“一夫一妻制”的哺乳動物。
This is where the vasopressin and oxytocin come in. They are involved in parts of the brain that help to pick out the salient features used to identify individuals. If the gene for oxytocin is knocked out of a mouse before birth, that mouse will become a social amnesiac and have no memory of the other mice it meets. The same is true if the vasopressin gene is knocked out.
抗利尿激素和催產(chǎn)素就是從這里進入這個科學(xué)傳說的。它們參與了大腦一些部分的工作，以幫助選出用于辨別個體的顯著特征。 如果在老鼠出生前，DNA中的抗利尿激素基因即被剔除, 那只老鼠將會成為一個社會性失憶個體，它也不會對遇到的其他老鼠留下任何印象。如果催產(chǎn)素基因缺損，以上命題同樣成立。
The salient feature in this case is odour. Rats, mice and voles recognise each other by smell. Christie Fowler and her colleagues at Florida State University have found that exposure to the opposite sex generates new nerve cells in the brains of prairie voles—in particular in areas important to olfactory memory. Could it be that prairie voles form an olfactory “image” of their partners—the rodent equivalent of remembering a personality—and this becomes linked with pleasure？
這里的顯著特征是氣味。耗子、老鼠和野鼠靠嗅覺區(qū)分彼此。Christie Fowler和她的同事在佛羅里達州大學(xué)的研究中發(fā)現(xiàn)，把草原田鼠暴露給異性可使其大腦產(chǎn)生新的神經(jīng)細胞——在對嗅覺記憶至關(guān)重要的一些區(qū)域尤其如此。人類是靠個性特征來記住某一個人的。那么草原田鼠會構(gòu)造一個嗅覺“形像”去記住伴侶嗎？這與性愉悅是否存在關(guān)聯(lián)呢？
Dr Young and his colleagues suggest this idea in an article published last month in the Journal of Comparative Neurology. They argue that prairie voles become addicted to each other through a process of sexual imprinting mediated by odour. Furthermore, they suggest that the reward mechanism involved in this addiction has probably evolved in a similar way in other monogamous animals, humans included, to regulate pair-bonding in them as well.
Young博士和他的同事在上個月《比較神經(jīng)學(xué)期刊》的文章中提到了這種想法。他們認為草原田鼠通過一個由氣味做媒介的性烙印過程使配偶彼此沉溺于對方。此外，他們還提到，與這彼此沉溺上癮相關(guān)的獎賞機制在其他的一夫一妻制動物（包括人類）生理系統(tǒng)中，或許也進化成了相似的方式，以規(guī)范他們的配偶聯(lián)結(jié)關(guān)系。
You might as well face it …… 你或許也會面對它……
Sex stimulates the release of vasopressin and oxytocin in people, as well as voles, though the role of these hormones in the human brain is not yet well understood. But while it is unlikely that people have a mental, smell-based map of their partners in the way that voles do, there are strong hints that the hormone pair have something to reveal about the nature of human love： among those of Man's fellow primates that have been studied, monogamous marmosets have higher levels of vasopressin bound in the reward centres of their brains than do non-monogamous rhesus macaques.
雖然抗利尿激素和催產(chǎn)素在人腦內(nèi)的角色仍未被透徹了解，但與田鼠一樣，人體在受到性刺激時也會釋放這些荷爾蒙。盡管與田鼠不一樣，人類不太可能有一張基于嗅覺的神經(jīng)系統(tǒng)伴侶圖譜，但若干線索已有力說明，這兩種荷爾蒙能揭示一些人類戀愛的本質(zhì)∶在已被研究過的人類靈長目同伴之中，一夫一妻制小長尾猴的大腦獎賞中樞系統(tǒng)中，抗利尿激素水平較非一夫一妻制的恒河短尾猿高。
Other approaches are also shedding light on the question. In 2000, Andreas Bartels and Semir Zeki of University College, London, located the areas of the brain activated by romantic love. They took students who said they were madly in love, put them into a brain scanner, and looked at their patterns of brain activity.
其他方法也正在為人們尋找這些問題的謎底。2000 年，來自倫敦市大學(xué)學(xué)院的Andreas Bartels和Semir Zeki定位出了能被浪漫愛情激活的大腦區(qū)域。兩位學(xué)者選擇自稱正在熱戀的學(xué)生作為測試目標，利用腦掃描儀對他們的大腦活動模式進行觀測。
The results were surprising. For a start, a relatively small area of the human brain is active in love, compared with that involved in, say, ordinary friendship. “It is fascinating to reflect”, the pair conclude, “that the face that launched a thousand ships should have done so through such a limited expanse of cortex.” The second surprise was that the brain areas active in love are different from the areas activated in other emotional states, such as fear and anger. Parts of the brain that are love-bitten include the one responsible for gut feelings, and the ones which generate the euphoria induced by drugs such as cocaine. So the brains of people deeply in love do not look like those of people experiencing strong emotions, but instead like those of people snorting coke. Love, in other words, uses the neural mechanisms that are activated during the process of addiction. “We are literally addicted to love,” Dr Young observes. Like the prairie voles.
令人驚訝的是：首先，人腦參與到戀愛的活動區(qū)域，較之其他感情（如普通友誼），相對要比較小些?！耙俗⒁獾氖?，結(jié)果顯示，”兩位學(xué)者推斷說，“美麗的面容是通過控制一個有限區(qū)域的大腦皮層來實現(xiàn)‘一顧傾人城，再顧傾人國’的?！?第二個驚奇之處是，大腦內(nèi)因戀愛而活躍的區(qū)域不同于因其他情緒而活躍的區(qū)域，例如，恐懼和憤怒。 被戀愛“咬住”的那部份大腦還包括負責(zé)內(nèi)臟感覺和因可卡因等毒品生成快感的區(qū)域。因此，因此，深墜愛河的戀人們的大腦，并非類同于經(jīng)歷強烈情緒波動的人，倒更接近那些鼻吸可卡因的癮君子。換句話說，愛情使用的是在成癮過程中被激活的神經(jīng)機制。“嚴格地講, 我們成癮于愛情，”Young博士評述道，“就如同草原田鼠”。
It seems possible, then, that animals which form strong social bonds do so because of the location of their receptors for vasopressin and oxytocin. Evolution acts on the distribution of these receptors to generate social or non-social versions of a vole. The more receptors located in regions associated with reward, the more rewarding social interactions become. Social groups, and society itself, rely ultimately on these receptors. But for evolution to be able to act, there must be individual variation between mice, and between men. And this has interesting implications.
那么看起來，能形成穩(wěn)固社會聯(lián)結(jié)的動物之所以愿意建立彼此間的伙伴關(guān)系，可能是由它們的抗利尿激素和催產(chǎn)素受體在大腦中的位置所決定。生物進化作用于以上受體在大腦的分布，而產(chǎn)生了社會性或非社會性不同版本的田鼠。位于獎賞機制有關(guān)區(qū)域的受體越多，對個體而言, 社會互動就更具有回報性。動物的社會性團體，乃至整個社會本身都最終依賴于這些受體。但要使進化真能發(fā)生效力，在鼠之鼠之間以及人與人之間，一定存在個體變異。這一論述還有引人入勝的推論。
Last year, Steven Phelps, who works at Emory with Dr Young, found great diversity in the distribution of vasopressin receptors between individual prairie voles. He suggests that this variation contributes to individual differences in social behaviour—in other words, some voles will be more faithful than others. Meanwhile, Dr Young says that he and his colleagues have found a lot of variation in the vasopressin-receptor gene in humans. “We may be able to do things like look at their gene sequence, look at their promoter sequence, to genotype people and correlate that with their fidelity,” he muses.
在Emory大學(xué)與Young博士一同工作的Steven Phelps去年發(fā)現(xiàn)，草原田鼠各個體間抗利尿激素受體的腦內(nèi)分布，存在著很大的差異。他提出，正是這一變異導(dǎo)致了社會行為的個體差異，換句話說，一些田鼠將會比另一些更加忠誠。同時，Young博士說他和同事已經(jīng)發(fā)現(xiàn)人類抗利尿激素受體基因的許多變異。“我們或許能夠做些類似于察看人們的基因序列，察看他們的啟動序列等工作，在此基礎(chǔ)上對人們進行基因型分類, 并把分類結(jié)果與他們的忠誠度關(guān)聯(lián)起來”，Young博士作如是想。
It has already proved possible to tinker with this genetic inheritance, with startling results. Scientists can increase the expression of the relevant receptors in prairie voles, and thus strengthen the animals' ability to attach to partners. And in 1999, Dr Young led a team that took the prairie-vole receptor gene and inserted it into an ordinary （and therefore promiscuous） mouse. The transgenic mouse thus created was much more sociable to its mate.
事實已經(jīng)證明可能對這種基因遺傳進行修補，并產(chǎn)生了令人吃驚的結(jié)果?？茖W(xué)家能增加草原田鼠相關(guān)受體的表達，以加強動物對同伴的依附能力。而且在 1999 年，Young博士帶領(lǐng)了一只研究隊伍，他們將草原田鼠的受體基因插入到一只平常（因此成為雜亂的） 老鼠的體內(nèi)，由此產(chǎn)生的轉(zhuǎn)基因鼠對它的配偶表現(xiàn)得更為友善。
Love, love me do 愛我，真心地愛我
Scanning the brains of people in love is also helping to refine science's grasp of love's various forms. Helen Fisher, a researcher at Rutgers University, and the author of a new book on love*, suggests it comes in three flavours： lust, romantic love and long-term attachment. There is some overlap but, in essence, these are separate phenomena, with their own emotional and motivational systems, and accompanying chemicals. These systems have evolved to enable, respectively, mating, pair-bonding and parenting.
對戀愛中人們大腦的掃描，也有助于使科學(xué)對各種形式愛情的領(lǐng)會變得更為精確。Rutgers 大學(xué)的一位研究人員Helen Fisher，同時是一本關(guān)于愛情的新書作者，她提出，愛會以三種滋味出現(xiàn)：欲望，浪漫的戀愛和長期的附屬關(guān)系。三種滋味的愛情雖有一些重疊，但本質(zhì)上是截然不同的現(xiàn)象，并且具有各自的情緒和激發(fā)系統(tǒng)，以及相伴的體內(nèi)化學(xué)物質(zhì)。這些系統(tǒng)通過進化后以分別讓交配，伴侶聯(lián)接和養(yǎng)育子女成為可能。
Lust, of course, involves a craving for sex. Jim Pfaus, a psychologist at Concordia University, in Montreal, says the aftermath of lustful sex is similar to the state induced by taking opiates. A heady mix of chemical changes occurs, including increases in the levels of serotonin, oxytocin, vasopressin and endogenous opioids （the body's natural equivalent of heroin）. “This may serve many functions, to relax the body, induce pleasure and satiety, and perhaps induce bonding to the very features that one has just experienced all this with”, says Dr Pfaus.
首先當(dāng)然是欲望，包括對性的強烈渴求。蒙特利爾Concordia大學(xué)的一位心理學(xué)家，Jim Pfaus說道，貪欲的性行為其結(jié)果和使用鴉片引起的狀況頗相類似：一種令人興奮的混合化學(xué)變化，包括血液復(fù)合胺（5羥色氨），催產(chǎn)素，抗利尿激素和內(nèi)非肽（身體內(nèi)的海洛英的天然同等物） 的水平升高?！斑@可能提供許多功能，如放松身體，產(chǎn)生快樂和滿足感, 也可能導(dǎo)致把某些特征與剛才的全部經(jīng)歷聯(lián)結(jié)起來，”Pfaus博士補充道。
Then there is attraction, or the state of being in love （what is sometimes known as romantic or obsessive love）. This is a refinement of mere lust that allows people to home in on a particular mate. This state is characterised by feelings of exhilaration, and intrusive, obsessive thoughts about the object of one's affection. Some researchers suggest this mental state might share neurochemical characteristics with the manic phase of manic depression. Dr Fisher's work, however, suggests that the actual behavioural patterns of those in love—such as attempting to evoke reciprocal responses in one's loved one—resemble obsessive compulsive disorder （OCD）.
接下來便是兩性吸引，雙方處于相愛的狀態(tài) （就是我們所知的浪漫的、或強迫性的戀愛）。這是純粹的欲望的升華，它使人們總能回到某個特定配偶身邊。這種狀態(tài)的特征，是興奮感和對情感對象打擾式的和強迫性的思戀。一些研究員提到，這一心理狀態(tài)可能和狂躁狀態(tài)的躁郁癥有相同的神經(jīng)化學(xué)特征。Fisher博士的工作揭示了戀愛人群真實的行為模式，比如：試圖喚起被愛者的報答——類似于強迫性混亂癥（OCD）。
That raises the question of whether it is possible to “treat” this romantic state clinically, as can be done with OCD. The parents of any love-besotted teenager might want to know the answer to that. Dr Fisher suggests it might, indeed, be possible to inhibit feelings of romantic love, but only at its early stages. OCD is characterised by low levels of a chemical called serotonin. Drugs such as Prozac work by keeping serotonin hanging around in the brain for longer than normal, so they might stave off romantic feelings. （This also means that people taking anti-depressants may be jeopardising their ability to fall in love.） But once romantic love begins in earnest, it is one of the strongest drives on Earth. Dr Fisher says it seems to be more powerful than hunger. A little serotonin would be unlikely to stifle it.
這又產(chǎn)生一個問題，即是否可能和處理OCD一樣，用病理學(xué)方式來“處治”這種浪漫狀態(tài)。任何沉醉于愛情的青少年，他們的父母可能都想知道相應(yīng)的答案。Fisher博士提出，抑制浪漫愛情的可能性確實存在，但只能是在感情發(fā)展的最初階段。OCD的特征，是血液中一種叫血液復(fù)合胺（5羥色氨）的含量較低。如果Prozac等藥物讓血液中的復(fù)合氨在大腦中停留得比正常時間更久，這些藥品就可能阻止浪漫感覺的出現(xiàn)。（這也意味著服用抗抑郁藥物的人們可能正在危及他們彼此相愛能力。）真摯浪漫的愛情一旦開始，它就成為了地球上大的動力之一。Fisher博士說，這種欲望比食欲強大得多，一點兒血液中的復(fù)合氨不太可能扼殺心中如此強烈的情感。
Wonderful though it is, romantic love is unstable—not a good basis for child-rearing. But the final stage of love, long-term attachment, allows parents to co-operate in raising children. This state, says Dr Fisher, is characterised by feelings of calm, security, social comfort and emotional union.
盡管浪漫的愛情如此奇妙，但它卻并不穩(wěn)定——這絕非養(yǎng)兒育女的良好基礎(chǔ)。而愛情的最后階段，即長期的附屬關(guān)系，卻使父母在養(yǎng)育孩子方面得以精誠合作——這種狀態(tài)，F(xiàn)isher博士認為，它的特征恰恰是平穩(wěn)感、安全感、社會性的慰籍以及情感的結(jié)合。
Because they are independent, these three systems can work simultaneously—with dangerous results. As Dr Fisher explains, “you can feel deep attachment for a long-term spouse, while you feel romantic love for someone else, while you feel the sex drive in situations unrelated to either partner.” This independence means it is possible to love more than one person at a time, a situation that leads to jealousy, adultery and divorce—though also to the possibilities of promiscuity and polygamy, with the likelihood of extra children, and thus a bigger stake in the genetic future, that those behaviours bring. As Dr Fisher observes, “We were not built to be happy but to reproduce.”
因為三個階段的系統(tǒng)彼此獨立，所以他們可能同時工作而導(dǎo)致危險的后果。如Fisher博士解釋的那樣，“你可能對長期配偶有深深的附屬感，同時你又因另一人而感受到浪漫的愛情，其間，你又由于第三位異性而產(chǎn)生性驅(qū)動力。”這種獨立性意味著你可能同時愛上多個異性而導(dǎo)致妒忌、私通和離婚——盡管也有可能是亂交、一夫多妻、和隨之而來的額外生育，即最終一個更大的預(yù)期基因賭注。正如Fisher博士所述，“我們不是為快樂卻是為了生殖而被創(chuàng)造的。”
The stages of love vary somewhat between the sexes. Lust, for example, is aroused more easily in men by visual stimuli than is the case for women. This is probably why visual pornography is more popular with men. And although both men and women express romantic love with the same intensity, and are attracted to partners who are dependable, kind, healthy, smart and educated, there are some notable differences in their choices. Men are more attracted to youth and beauty, while women are more attracted to money, education and position. When an older, ugly man is seen walking down the road arm-in-arm with a young and beautiful woman, most people assume the man is rich or powerful.
愛情的各階段在性別之間略有差別。例如，與女性相比，男性的欲望更容易被視覺刺激喚醒。這或許就是為什么視覺色情對男性而言更加流行。雖然男人和女人用同樣的強度表達浪漫的愛情，也同樣會被可靠、和藹、健康、聰明和有教養(yǎng)的伴侶所吸引，但不同性別在選擇配偶時還是有著一些顯著的不同。男性更易被年輕和美貌所吸引，而女性更多會青睞于金錢、教育和地位。當(dāng)人們看到蒼老而丑陋的男人手挽著年輕美麗的女子漫步道旁，大多數(shù)都會設(shè)想此公不是腰纏萬貫，便有大權(quán)在握。
These foolish things 這些愚蠢的玩意兒
Of course, love is about more than just genes. Cultural and social factors, and learning, play big roles. Who and how a person has loved in the past are important determinants of his （or her） capacity to fall in love at any given moment in the future. This is because animals—people included—learn from their sexual and social experiences. Arousal comes naturally. But long-term success in mating requires a change from being naive about this state to knowing the precise factors that lead from arousal to the rewards of sex, love and attachment. For some humans, this may involve flowers, chocolate and sweet words. But these things are learnt.
當(dāng)然，愛情不止與基因有關(guān)。文化社會因素和后天的學(xué)習(xí)在其中也扮演著重要的角色。一個人曾經(jīng)愛過誰？如何愛過？對他（她）將來任何時刻的相愛能力都是決定性的因素，因為動物（包括人類）能從他們的性和社會經(jīng)驗中進行學(xué)習(xí)。性喚醒可本能地產(chǎn)生，但長期而成功的配偶關(guān)系，卻需要一個對愛情各種精確因素從無知到熟悉的改變過程，這個過程包括由性喚醒而導(dǎo)致性行為、愛和附屬關(guān)系產(chǎn)生對大腦的獎賞。對于一些人來說，這可能包括鮮花、巧克力和甜言蜜語：這些都是可以學(xué)會的。
If humans become conditioned by their experiences, this may be the reason why some people tend to date the same “type” of partner over and over again. Researchers think humans develop a “l(fā)ove map” as they grow up—a blueprint that contains the many things that they have learnt are attractive. This inner scorecard is something that people use to rate the suitability of mates. Yet the idea that humans are actually born with a particular type of “soul mate” wired into their desires is wrong. Research on the choices of partner made by identical twins suggests that the development of love maps takes time, and has a strong random component.
人類常常會囿于自身的經(jīng)驗，因此某些人總喜歡一再地和相同“類型”伴侶約會。研究人員認為，隨著人們年齡的增長，他們會在大腦內(nèi)發(fā)展一個“愛情地圖”——一個包含許多人們已經(jīng)熟悉的、魅力事物的藍圖。這個內(nèi)部記分卡是人們用于評價配偶適合度的依據(jù)。認為特定類型的“精神伴侶”與欲望的內(nèi)在聯(lián)系是與生俱來，這種想法是錯誤的。對同卵雙胞胎擇偶的研究表明，愛情地圖的發(fā)展需要時間，而且有很強的隨機成份。
Work on rats is leading researchers such as Dr Pfaus to wonder whether the template of features found attractive by an individual is formed during a critical period of sexual-behaviour development. He says that even in animals that are not supposed to pair-bond, such as rats, these features may get fixed with the experience of sexual reward. Rats can be conditioned to prefer particular types of partner—for example by pairing sexual reward with some kind of cue, such as lemon-scented members of the opposite sex. This work may help the understanding of unusual sexual preferences. Human fetishes, for example, develop early, and are almost impossible to change. The fetishist connects objects such as feet, shoes, stuffed toys and even balloons, that have a visual association with childhood sexual experiences, to sexual gratification.
針對家鼠的研究工作使Pfaus博士等研究人員力圖查明：具有異性魅力的特征模板，是不是在性行為發(fā)展的關(guān)鍵時期形成的？他認為，即使在沒有伴侶連接習(xí)性的動物當(dāng)中——如家鼠——這些特征仍可能通過性獎賞的經(jīng)驗固定下來。家鼠能條件反射地偏愛特別類型的伴侶。舉例來說，性獎賞同時伴隨著某種提示條件，比如具有檸檬氣息的異性。這項工作也許有助于對異常的性偏愛的理解。例如，人類的戀物情結(jié)發(fā)展于早期，而且?guī)缀跏遣豢筛淖?。戀物癖者會把童年時期在視覺上和性經(jīng)驗關(guān)聯(lián)的物體與性滿足連接起來，諸如腳、鞋子、布玩具甚至氣球等。
So love, in all its glory, is just, it seems, a chemical state with genetic roots and environmental influences. But all this work leads to other questions. If scientists can make a more sociable mouse, might it be possible to create a more sociable human？ And what about a more loving one？ A few people even think that “paradise-engineering”, dedicated to abolishing the “biological substrates of human suffering”, is rather a good idea.
因此，關(guān)于愛的所有光彩之處，看上去只不過是具有遺傳基礎(chǔ)和受環(huán)境影響的一種化學(xué)狀態(tài)。與此相關(guān)，這兒涉及的一切還將導(dǎo)致更多其他的問題。如果科學(xué)家能制造一只社會性更強的老鼠，那么他們是否可能產(chǎn)生一個社會性更強的人呢？創(chuàng)造一個更惹人喜愛的人，其結(jié)果又將如何？一些人甚至認為致力于廢除“人類受難的生物學(xué)基體”的“天堂工程”，是一個非常不錯的主意。
As time goes by 時光流逝
Progress in predicting the outcome of relationships, and information about the genetic roots of fidelity, might also make proposing marriage more like a job application—with associated medical, genetic and psychological checks. If it were reliable enough, would insurers cover you for divorce？ And as brain scanners become cheaper and more widely available, they might go from being research tools to something that anyone could use to find out how well they were loved. Will the future bring answers to questions such as： Does your partner really love you？ Is your husband lusting after the au pair？
通過彼此關(guān)聯(lián)的醫(yī)學(xué)、遺傳基因和心理學(xué)的檢查，預(yù)測人際關(guān)系最終結(jié)果的研究進展和關(guān)于忠誠度的遺傳基礎(chǔ)信息，能使求婚變得更像工作申請。如果這個結(jié)論足夠可信，保險公司會為你的婚姻投保嗎？當(dāng)腦掃描儀變得更便宜更普及，它能由研究工具變成任何人都可以用于發(fā)現(xiàn)他們被愛到何種程度的手段嗎？未來會不會就如下問題為人類找到答案：你的伴侶是否真的愛你？ 你的丈夫是否正對來家打工的留學(xué)女生暗送秋波？
And then there are drugs. Despite Dr Fisher's reservations, might they also help people to fall in love, or perhaps fix broken relationships？ Probably not. Dr Pfaus says that drugs may enhance portions of the “l(fā)ove experience” but fall short of doing the whole job because of their specificity. And if a couple fall out of love, drugs are unlikely to help either. Dr Fisher does not believe that the brain could overlook distaste for someone—even if a couple in trouble could inject themselves with huge amounts of dopamine.
接下來當(dāng)然會有相應(yīng)的藥物。盡管Fisher博士對此有所保留。我們還是想問：藥物是否可能幫助人們墜入愛河，或者破鏡重圓？ 或許不能完全做到，但卻可能部分地提高“戀愛體驗”。對此另一位學(xué)者Pfaus博士如是說：藥物達不到整體提高的效果，因為藥畢竟是藥，這就是它的特殊性。如果一對夫婦不再相愛，藥物多半無能為力。Fisher博士不相信大腦可以忽略對某人的厭惡——即使對婚姻危機中的夫婦大量注射的多巴氨，也于事無補。
However, she does think that administering serotonin can help someone get over a bad love affair faster. She also suggests it is possible to trick the brain into feeling romantic love in a long-term relationship by doing novel things with your partner. Any arousing activity drives up the level of dopamine and can therefore trigger feelings of romance as a side effect. This is why holidays can rekindle passion. Romantics, of course, have always known that love is a special sort of chemistry. Scientists are now beginning to show how true this is.
然而，她確實認為調(diào)控血液復(fù)合胺（5羥色氨）水平能更快地幫助人走出戀愛的低谷。她同時建議和你的伴侶做一些新鮮事，這樣可能哄騙大腦在長期兩性關(guān)系中依然能感覺到愛情的甜美。任何喚醒活動都會提高多巴胺的水平而引發(fā)浪漫的感受。這就是為什么假日能重新點燃激情的原因所在。當(dāng)然，愛情浪漫主義者總是認為愛情是一種特殊的化學(xué)，而正是科學(xué)家們，現(xiàn)在開始展示出了這一看法是如何的千真萬確。