Why do women cry? Because they feel sad, obviously。

But that might not be the only reason, according to a new study. It suggests that women's tears contain chemicals that send men a powerful if unspoken message:

Sex? Now? Fugeddaboudit。

Scientists at Israel's Weizmann Insitute had men sniff the tears of women who had cried while watching sad movies. As the men sniffed, they watched images of the women on a computer screen。

What happened? The tears didn't make the men sad. They didn't make them more empathetic. But they did make the women's faces less sexually appealing to the men。

And when the researchers tested the men's blood, they found that the "chemosignals" in women's tears triggered a steep decline in testosterone, a hormone that is related to sexual arousal。

What does it all mean? The findings seem to raise more questions than they answered。

"What is the chemical involved?" study scientist Noam Sobel, a professor of neurobiology at the institute, asked in a written statement. "Do different kinds of emotional situations send different tear-encoded signals?"

Sobel doesn't think women are the only ones whose tears send signals。

"We don't think there is something special about women's tears," he said. "We definitely predict chemical signals in men's tears and children's tears too."

The study was published in the journal "Science."

一項新的研究表明，女人的眼淚會降低男人的性欲望。

以色列魏茲曼研究所的科學家們發(fā)現，女人的眼淚中含有一種“化學信號”，它是降低男同胞性欲的罪魁禍首。

Noam Sobel教授在“BBC服務世界”電臺上說，這種信號能夠減少睪丸激素和減低大腦對性的興奮。

他的研究小組現在正計劃研究男人的眼淚對女人和男人的作用。

睪丸激素

研究人員收集了女性自愿者在看悲傷電影時的淌下的眼淚。

將眼淚和鹽分的溶液放在墊子上，讓男性志愿者用鼻子聞吸，當然，他們并不知道自己聞的是眼淚還是鹽分，并且讓他們邊聞邊看一些女性的面部照片，并對之做評價。然后，再做一次相同的實驗，不過讓第一次聞眼淚的男同胞聞吸鹽分溶液，讓第一次聞鹽分的男同胞聞吸眼淚溶液。

研究人員發(fā)現，女性照片對聞吸眼淚者的性吸引力比聞吸鹽分溶液者要小。

在聞吸了眼淚溶液的男性志愿者的唾液中，睪丸激素-一種能激發(fā)性興奮的荷爾蒙激素-平均降低了13%，但是聞吸了鹽分溶液的卻不變。

并且通過測量，聞吸眼淚者的皮膚溫度、心率、呼吸也下降了。

另外，通過核磁共振成像，在聞吸眼淚者的大腦中，性感知部位活躍程度降低。

研究人員稱，眼淚是無味的，男性志愿者并不能區(qū)別他們聞的是眼淚還是鹽分。

“這項研究證實了一種觀點：人類自身的化學信號--即便是那些我們還沒有搞清楚的--影響這其他人的行為”，Sobel教授在《科學快訊》的在線雜志上如是評論到。

另外，他還說，這項研究的結果引發(fā)了很多問題，比如發(fā)出這種信號的化學物是什么。