Maintaining a strong social bond takes time and effort. That's according to evolutionary psychologists who studied the social lives of our closest primate relatives. 

 

维持牢固的社会联系需要时间和精力。这是进化心理学家们在研究了我们的灵长类近亲的社交生活后得出的结论。

 

Whether you're a monkey or a human, the strength of a bond is directly linked to the amount of time you spend together, and a friendship can deteriorate beyond repair in just three months.

 

This, scientists say, is likely to be bad news for what they call our more marginal friendships. Without the reinforcement of a shared workplace or a chat at the school gates, some less valued relationships could be irreparably damaged by lockdown.

 

Many people have swapped face-to-face contact for video chats, but the researchers say that this and social distancing has left us deprived of human touch.

 

Just like the grooming that chimpanzees spend hours doing, a welcome squeeze on the arm or a cuddle from a friend causes our brains to release pleasure-boosting chemicals. That helps explain why many of us might feel we're fighting a pretty fundamental need for a hug.