伴侶懷孕時，男性易出軌？

A new study found that men show shifts in behavior from mating-oriented to parent-oriented while their partners’ pregnancy develops. These changes are determined by changes in testosterone levels across pregnancy and hormonal linkage with their partner。
一項新的研究發(fā)現(xiàn)，在伴侶懷孕時，男性的行為會從交配導向型轉變?yōu)榧议L導向型。決定這一轉變的是伴侶懷孕期間男性睪丸素水平的變化，以及他們與伴侶之間的荷爾蒙聯(lián)動。

It’s almost hard to imagine that every caring dad was once a skirt-chasing ball of hormones — but it’s true. Somewhere along their transition to parenthood, biology puts a stop to men’s carefree days of sowing wild oats and turns their attention towards nurturing children. This is a very solid strategy from an evolutionary point of view, but we didn’t know exactly how it happened. 
難以想象每個慈愛的爸爸都曾是一團追逐女性的荷爾蒙——但這是真的。在轉變?yōu)槿烁傅倪^程中，生物機制使男性結束了逍遙自在、四處播種的日子，并將注意力轉到養(yǎng)育孩子上。從進化的角度來看，這是一個非?？煽康膽?zhàn)略，但我們并不確切知道它是如何發(fā)生的。

A new study found that the answer may be testosterone. While high levels of this androgenic steroid hormone have been associated with aggression and competitive behavior, lower levels promote nurturing behaviors, particularly those related to caring for offspring. 
一項新的研究發(fā)現(xiàn)，答案可能是睪丸素。盡管高水平的這種雄性類固醇激素與侵略性和競爭性行為有關，低水平時則促進養(yǎng)育性行為，特別是那些與照顧子女相關的行為。

Previous studies show that fathers who are in a relationship and are more involved with children’s care show lower testosterone levels that men who don’t have children. Lower levels of salivary testosterone have also been tied to higher self-reported levels of relationship satisfaction and commitment, a lower interest in sex outside of marriage and a lower chance of divorce. So it would seem that a father’s decrease in testosterone levels during the transition to parenthood leads him from exploring new mating opportunities towards investment into the current relationship and caring for offspring. 
之前的研究表明，處在一段親密關系中且更多地參與照看孩子的父親，其睪丸素水平低于沒有孩子的男性。與低水平的唾液睪酮相關的是較高水平的愛情滿意度和忠誠度，男性對婚外性的興趣較低，離婚的幾率也較低。因此，似乎在向人父轉變的過程中，父親的睪丸素水平下降，會使其停止尋求新的交配機會，投身于目前的關系及照顧后代。

Led by Darby Saxbe of the University of Southern California, the study followed 27 couples expecting their first child during pregnancy and first few months after birth. The parents’ testosterone levels were measured during this pregnancy, and participants rated their investment, commitment, and satisfaction with their partner a few months after their child’s birth. 
這項研究由南加州大學的Darby Saxbe帶領，他們追蹤了27對夫妻懷第一胎以及孩子出生后幾個月里的情況。他們測量了在懷孕期間家長們的睪丸素水平。孩子出生后的幾個月中，參與調(diào)查的夫妻還要對自身的投入度，忠誠度和對伴侶的滿意度進行打分。

The team found that fathers showed significant declines in testosterone while the pregnancy progressed, and a significant positive correlation with the mother’s testosterone levels. A better correlation between the mother’s and father’s testosterone levels during pregnancy was associated with higher levels of father involvement after the child’s birth — the degree of synchrony between the parents predicted the fathers’ investment, commitment, and satisfaction in the couple relationship. 
該研究小組發(fā)現(xiàn)，在伴侶懷孕期間，父親的睪丸素水平出現(xiàn)明顯的下降，并且與母親的睪丸素水平呈顯著的正相關。在懷孕期間母親和父親的睪丸素水平之間的相關性越好，孩子出生后父親的參與程度越高——父母之間的同步程度預示著父親的投入度、忠誠度和對夫妻關系的滿意度。