最新研究：睪丸激素與自閉癥沒有直接關系

一項重大的新研究，推翻了之前有爭議的自閉癥假說

A compelling new study has found no link between testosterone in men and reduced cognitive empathy, a trait that is characteristically impaired in autism spectrum disorders.

一項引人注目的新研究發(fā)現(xiàn)，男性體內(nèi)的睪酮與認知同理能力下降之間沒有聯(lián)系，而認知同理心在自閉癥譜系障礙中是典型的受損特征。

Ever since the very first clinical account of autism, almost eighty years ago, far more male children and adults have been placed on the spectrum than females. In all that time, no has been able to figure out why.

自從近80年前首次對自閉癥進行臨床研究以來，越來越多的男性兒童和成人被納入自閉癥研究范圍。一直以來，沒有人能找出原因。

Today, one of the most popular and commonly cited hypotheses is also one of the most controversial. First proposed by psychologist Simon Baron-Cohen, the 'extreme male brain' (EMB) hypothesis suggests high levels of prenatal hormones in the womb can lead to hyper-masculine traits later on, such as a reduced ability to read emotions in others.

如今，最流行和最常被引用的假設之一也是最具爭議的假設之一。“極端男性大腦”(EMB)假說最早由心理學家西蒙•巴倫-科恩提出，該假說認為，子宮內(nèi)的高水平產(chǎn)前激素會導致日后的男性特征過于男性化，比如解讀他人情緒的能力下降。

Evidence for this theory is highly disputed on many different levels. Because it's too dangerous to manipulate prenatal testosterone in human subjects, most previous studies on the role of testosterone have relied on correlations only.

這一理論的證據(jù)在許多不同層面上都有很大爭議。因為在人類受試者中控制產(chǎn)前睪酮太危險了，以前大多數(shù)關于睪酮作用的研究都只依賴于相關性。

Researchers have, for example, tested testosterone in adults and used digit ratios as a proxy for prenatal testosterone levels.

例如，研究人員對成年人進行了睪酮測試，并用手指比例作為產(chǎn)前睪酮水平的指標。

What's more, much of this research is small and inconsistently replicated. A study co-authored by Baron-Cohen in 2011, for instance, was only conducted among 16 young women. It found that when testosterone was administered to these participants, it reduced their performance on a test of reading others' emotions, called Reading the Mind in the Eyes Test (RMET).

更重要的是，這項研究的大部分都是小規(guī)模的，重復性不一致。例如，2011年由科恩男爵(baron cohen)合著的一項研究，只在16名年輕女性中進行。研究發(fā)現(xiàn)，當這些參與者服用睪酮時，他們在一項名為“眼睛讀心術”(RMET)的測試中的表現(xiàn)會下降。

The study also found a link between the ratio of the second and fourth finger, known as the 2D:4D ratio, and a woman's sensitivity to testosterone - an idea that has turned up mixed results and is highly controversial as proxy for the prenatal environment.

這項研究還發(fā)現(xiàn)，第二和第四指的比例(稱為2d:4d比例)與女性對睪丸激素的敏感度之間存在聯(lián)系——這一觀點出現(xiàn)了各種各樣的結(jié)果，作為產(chǎn)前環(huán)境的代表，備受爭議。

"People referred to that original study as if it was a solid stepping stone," Amos Nadler, a neuro-economist at the University of Toronto, told Science magazine.

多倫多大學(University of Toronto)神經(jīng)經(jīng)濟學家納德勒(Amos Nadler)在接受《科學》雜志采訪時說：“人們把這項最初的研究稱為堅實的墊腳石。”

"Pardon my French, but nobody was calling bullshit."

“請原諒我的法語，但沒人說胡話。”

Delving deeper, Nadler and his colleagues conducted two randomised controlled studies with samples that were 15 and 25 times greater than the original 2011 study. They also decided to focus only on males, as males are roughly four times more likely to be diagnosed with autism.

深入研究，納德勒和他的同事進行了兩項隨機對照研究，樣本數(shù)量分別是2011年原始研究的15倍和25倍。他們還決定只關注男性，因為男性被診斷患有自閉癥的可能性大約是女性的四倍。

Conducting one of the largest studies to date, the researchers administered testosterone or a placebo to 643 male participants. To avoid giving people the same test twice - a pitfall of previous research - the researchers split participants into two groups.

研究人員進行了迄今為止規(guī)模最大的研究之一，對643名男性參與者使用睪丸激素或安慰劑。為了避免讓人們進行兩次相同的測試——這是之前研究的一個陷阱——研究人員將參與者分成兩組。

The first group, composed of 243 volunteers, had their testosterone levels measured for a baseline and then completed the first half of a cognitive empathy test, the same one that was used in the 2011 study. This group was then given a single dose of testosterone gel or a placebo on the shoulder and finished the rest of the test.

第一組由243名志愿者組成，測試他們的睪酮水平作為基線，然后完成認知移情測試的前半部分，與2011年研究中使用的相同。然后在肩膀上注射單劑量的睪丸酮凝膠或安慰劑，完成其余的測試。

The second group, composed of 400 people, undertook the same routine but this time with a nasal gel. The fingers of each participant in each group were also measured.

第二組，由400人組成，進行同樣的程序，但這次使用的是鼻凝膠。還測量了每組參與者的手指。

"Our research shows that there is not a causal relationship between testosterone levels and the capacity to understand others' thoughts and feelings, which is a hallmark impairment of autism spectrum disorders," Nadler told ScienceAlert.

納德勒在接受《科學警報》采訪時說：“我們的研究表明，睪丸激素水平與理解他人想法和感受的能力之間沒有因果關系，這是自閉癥譜系障礙的一個標志性損害。”

The behavioural economist says the new results cast serious doubt on previous studies, suggesting that past conclusions were "underpowered and therefore unreliable". As such, he says they make poor evidence for the extreme male brain theory, and he suggests that the role of testosterone in cognitive empathy is much more complex than we often think.

這位行為經(jīng)濟學家表示，新的研究結(jié)果對之前的研究提出了嚴重質(zhì)疑，表明過去的結(jié)論“力度不足，因此不可靠”。因此，他說，他們?yōu)闃O端的男性大腦理論提供了很差的證據(jù)，他認為睪丸激素在認知同理心中的作用比我們通常認為的要復雜得多。

"We found that there is no evidence to support this effect of testosterone, but that doesn't rule out any possible effects," says Gideon Nave, a marketing researcher at the University of Pennsylvania.

賓夕法尼亞大學的市場研究員吉迪恩·納維說：“我們發(fā)現(xiàn)沒有證據(jù)支持睪酮的這種作用，但這并不排除任何可能的影響。”

"From what we know, though, it seems that if testosterone does have an influence, the effect is complex, not linear. Reality is typically not that simple."

“不過，據(jù)我們所知，似乎如果睪丸激素確實有影響，這種影響是復雜的，而不是線性的?，F(xiàn)實通常不是那么簡單。”

The new findings are supported by other recent studies that have found no relationship between prenatal testosterone exposure and autistic traits.

這一新發(fā)現(xiàn)得到了最近其他研究的支持，這些研究發(fā)現(xiàn)產(chǎn)前睪酮暴露與自閉癥特征之間沒有關系。