Job flexibility is the key to keeping workers happy, productive and loyal to the company, a new study shows.

Researchers at Wake Forest University School of Medicine in Winston-Salem, North Carolina, found that workers who enjoyed more work flexibility were also less likely to say health problems affected their performance at work.

"For managers, the results suggest that implementing flexible work arrangements can contribute to the bottom-line," said Joseph Grzywacz, a professor of family medicine at the university.

Workplace flexibility refers to the ability of employees to modify where, when and how long work their work is performed.

Telecommuting, flexitime and job sharing were the main types of flexibility cited in the study published in the Psychologist-Manager journal.

The researchers studied a health survey completed by 3,193 employees of a large multinational pharmaceutical company. They used the information to determine how increases or decreases in perceived flexibility from one year to the next were associated with a variety of factors.

Decreases in flexibility over the year were associated with reduced job commitment, but had little impact on absence, they said.

Offering a variety of alternative work arrangements and training managers and supervisors to be supportive of workers' personal lives may help in creating a culture of flexibility, researchers added.

别再寻找和你互补的爱人了，我们需要和自己相似的爱人，因为相似的相貌意味着我们有相似的个性。

新的研究显示，和某人在一起时间越长，我们和他的长相就越相似。

研究人员选取160对夫妻的单人照片，分别给11名的男性和11名女性看，让他们判断这些夫妻的年龄、魅力点和性格特征。但是在此之前，他们并不知道谁和谁是一对。

22名参与者把他们认为相貌和性格相似的人摆在一起，而他们也恰恰就是真正的夫妻。而且，在一起生活时间越长的夫妻，相似性就越明显。

研究人员认为共同的经历造成了他们的相似性。

英国利物浦研究人员托尼·利特尔说：相貌和性格之间有关系这一想法听起来有点怪异，但却是有生物学依据的。

他说：“睾丸激素直接影响男性化的脸型形成，也影响人的行为。脸可以反映我们的情绪，长时间重复一个表情也会改变我们的脸。”

例如，一个人总是笑就会产生笑纹，别人就能看出这个人生活挺幸福的。

此项研究显示，人们利用面部特征来判断某人的特点，对于每张脸，人们判断的依据也有所不同。但是眼睛和微笑绝对是判断的最重要依据。

利特尔说：“笑容是社交中十分重要的友好表示，眼睛也是精力是否集中的最有力证明。”

利特尔说：整个面部也很重要。例如，由宽下巴和上扬的眉峰等组成的男性化面部特征会让人觉得不友好、不愿意合作。