C

A little social support from your best buds goes a long way, whether you’re a human or a chimpanzee (黑猩猩). A new study that followed a chimpanzee community in the forests of Uganda has found that quality time with close companions significantly decreased stress hormone levels in the primates — whether they were resting, grooming or facing off against rival groups.

The findings, described this week in the journal Nature Communications, shed light on the physiological effects of close companionship in chimpanzees — and could have implications for human health too.

Researchers have long known that stress can worsen health and raise the risk of early death in humans as well as other social mammals.

“It can have effects on immune function, cardio function, fertility, cognition, and even your mood,” said study coauthor Kevin Langergraber, a primatologist at Arizona State University.

Maintaining close social bonds can help these animals (humans included) reduce some of that stress, potentially minimizing some health risks. But scientists have yet to pin down the exact physiological mechanisms at work.

“Social bonds make yosurvive and produce better — but how do they do that?” Langergraber said.

To find out, the international team of researchers studied members of the Sonso chimpanzee community in Uganda’s Budongo Forest, a group consisting of 15 males, 35 females and 28 juveniles and infants during the study period from February 2008 to July 2010.

Like humans, chimpanzees tend to have besties — bond partners with whom they appear to feel close. The researchers wanted to see whether interactions with these bond partners led to lower stress levels during particularly stressful situations, such as when fighting rival groups, or whether time spent with friends helped lower stress levels more generally, throughout the day.

The scientists observed the chimps perform three types of activities: resting, grooming or quarrelling with other groups of chimps. The researchers kept track of whether the chimps were doing any of these three things with their bond partners or with other chimps in their group.

A team of up to six observers watched the chimps and followed them around to collect urine (尿液) samples. The samples, collected from nine adult male and eight adult female chimps, were tested to see how much of the stress hormone cortisol they contained.

The scientists found that chimpanzees’ levels of urinary cortisol were 23% lower, on average, during the activities when they were with their bond partner. This was especially true for stressful activities, such as the intergroup rivalries, where any chimp on the front line might face physical harm or even death.

The findings in chimpanzees, some of our closest living relatives, could shed light on the role such close social relationships play in human health too, he said. Such friendships may be just as important during good times as bad — though more research needs to be done before any conclusions can be drawn.

“This has interest for a lot of people in a medical context as well,” Langergraber said.

61. The scientists carried out a research into chimpanzee community in Uganda ______.

A. to seek evidence of benefits of social bonds from physiological angle

B. to uncover whether social bonds make humans survive

C. to study how chimps perform three types of activities

D. to train chimps to maintain close social bonds with each other

62. What does the underlined word “they” in Paragraph 10 refer to?

A. Observers. B. Chimpanzees.

C. Urine samples. D. Bond partners.

63. The chimps’ levels of urinary cortisol decrease most when ______.

A. they are with other chimps in their group

B. they face the intergroup rivalries with friends

C. they perform three different types of activities

D. they spend time with friends throughout the day

64. What’s the author’s purpose in writing the passage?

A. To point out stress is harmful to all social mammals.

B. To illustrate how chimps control their stress level.

C. To urge scientists to do more research into chimpanzees.

D. To inform us friendships benefit both chimps and humans.

D

Dad and I loved baseball and hated sleep. One midsummer dawn when I was nine, we drove to the local park with our baseballs, gloves, and Yankees caps.

“If yothought night baseball was a thrill, just wait,” Dad told me. “Morning air carries the ball like you’ve never seen.”

He was right. Our fastballs charged faster and landed more lightly. The echoes of our catches popped as the sun rose over the dew-sprinkled fields.

The park was all ours for about two hours. Then a young mother pushed her stroller toward us. When she neared, Dad politely leaned over the stroller, waved, and gave the baby his best smile.

The mother stared at him for a second, and then rushed away.

Dad covered his mouth with his hand and walked to the car. “Let’s go, bud,” he said. “I’m not feeling well.”

A month earlier, Bell’s palsy (贝尔氏神经麻痹) had struck Dad, paralyzing the right side of his face. It left him slurring words and with a droopy eyelid. He could hardly drink from a cup without spilling onto his shirt. And his smile,which once eased the pain of playground cuts and burst forth at the mention of Mick Jagger, Woody Allen, or his very own Yankees, was gone.