What is the secret of friendship

 　　How long does it take for a person to form a friendship with another person? How many friends can a person make in a lifetime? Are friends the "right hand" to promote health? From the perspective of evolutionary psychology, scientists explain why human beings make friends and the unknown secrets of friendship.

　　"Only the most intelligent creatures have the conditions to make friends, and humans are the best of them." Robin Dunbar, an evolutionary psychologist at the University of Oxford in the United Kingdom, said.

　　 Now, scientists have interpreted why humans make friends from the perspective of evolutionary psychology, as well as the unknown secrets of friendship.

　　Two chemical substances promote friendship

　　 "For humans, friends are by no means an optional accessory." Lauren Brandt, an expert on friendship and social behavior at Duke University in the United States, said that from a scientific point of view, friendship activities It is related to the release of various neurotransmitters and biochemical substances that can make people feel happy. Among them, oxytocin and endorphins have the greatest effect.

　　 Jie Wei, PhD in neurobiology from Southern Medical University, explained that oxytocin is a neuropeptide that is secreted in large quantities during breastfeeding, which relaxes people and promotes the establishment of a loving bond between mother and child. In addition, it reduces anxiety and lowers blood pressure and heart rate. Over the course of evolution, this effect has been extended to include relationships such as friendships, Brandt said. Research has shown that oxytocin is released during physical contact with a friend, such as hugging, stroking and massaging, and the resulting euphoria encourages people to keep making friends. Even without physical contact, oxytocin can guide people to make pro-social decisions, promote trust, and encourage people to do good. Endorphins are neurotransmitters that make people feel happy. Dunbar did an experiment in which subjects were asked to row alone or in groups of two, and measured endorphin levels before and after rowing. It was found that people who rowed with a partner released more endorphins than those who rowed alone. These two chemical substances bring together strangers who have never met each other before, forming a wonderful network of relationships.

　　 So, how long does it take for a person to form a friendship with another person? Dunbar found through research that it takes 34 hours to form a friendship with a new acquaintance.

　　

　　Making friends benefits both body and mind

　　 Friends are "right-hand assistants" in promoting health. Fu Chunsheng, member of the Mental Health Consultation Center of the Institute of Psychology, Chinese Academy of Sciences, said that making friends has at least five benefits.

　　 People who are less likely to get sick and lack friends or have chronically poor relationships tend to have elevated levels of the stress hormone cortisol, a chronic state of stress that can be detrimental to health. This also explains why lonely people have a higher risk of cardiovascular disease and are more susceptible to infections. But if you are with friends, the cortisol in your body decreases, and you are less likely to get sick.

　　 Sleep more soundly A study by the University of Chicago in the United States found that the more lonely people are, the more times they suffer from insomnia. A Swedish study also showed that people who lack friends often suppress and hide their feelings, are more likely to suffer from insomnia, and may induce depression.

　　 Better memory, a study by Harvard University in the United States found that compared with the elderly who socialize frequently, the memory decline rate of the elderly with less social interaction is twice as fast. Studies have also found that socializing can improve age-related memory loss and allow the brain to reach its full potential.

　　 Smarter A study by Michigan State University in the United States found that making friends can make people smarter, because making friends requires dealing with strangers to exercise cognitive abilities. For example, if we want to extract topics of interest to different people, such as sports, entertainment, life, and fashion, from the brain "database", the cerebral cortex will always be in a state of excitement.

　　 Longevity A study by Flinders University in Australia found that the elderly who kept in touch with more than 5 close friends had a 22% reduction in mortality and an average life extension of 7 years. Fu Chunsheng said that sharing difficulties can halve sorrow, and sharing joy can double happiness. This may be because friends can help people relieve stress and solve difficulties, so that people can gain motivation in life.

　　Laughter, singing and dancing, and language are the "three treasures"

　　 of making friends. Regarding friendship, everyone may have a lot of doubts. For example, why are some people more relatable? A study in the United States pointed out that some people are naturally popular, which is determined by genes. However, it doesn't matter if you don't have the "friendship gene", because people are more willing to be friends with people who have similarities with them. There is a saying that "the appearance after the age of 35 is determined by oneself", so by constantly learning to be peaceful and self-cultivating in work and life, everyone may become a good-looking person.

　　 In addition, some researchers conducted an experiment in which they asked subjects to sleep in cotton T-shirts for two consecutive nights, avoiding all irritating smells to collect body odor, and then made them complete a series of social tests by randomly pairing them. interactive game.

　　The results of the experiment showed that the partners who felt most comfortable in the pairing game and being with each other had a higher similarity in body odor. The researchers therefore believe that body odor similarity plays a role in forming friendships, as people tend to communicate more positively with strangers who share a similar body odor.

　　 How many friends can a person make in a lifetime? Dunbar once proposed the famous "Dunbar Number", that is, affected by the evolution of the brain, the human cognitive ability allows an individual to have a maximum of 150 true friends (contacted at least once a year). But most people's private social circle does not exceed 150 people, about half of whom are family members.

　　 Dunbar also points out that friendships that aren't blood relatives can easily fade. If you don't get along with friends for a year, the friendship will fade by about 1/3. He believes that the quality of friendship is determined by the amount of time invested, and even group living mammals such as apes, which are lower than humans, establish and maintain friendship through social grooming. Human beings are smarter, mainly through laughter, singing and dancing, and language to connect emotions and expand social circles.

　　 In addition, experts remind that in order to obtain and consolidate friendship, we need to start from three aspects: one is to be sincere. When making friends, you must "emphasize friendship and despise interests", and you must not play tricks or tricks. Friends should be equal, not just make friends with "useful people" or divide friends into "grades"; the second is to manage well. Friendships take business and take time and effort to maintain. Meet on weekends to drink tea, chat about recent situations, and give small gifts during festivals, etc., will keep friendship fresh; the third is to praise more. In life, when someone smiles at you, you should also smile at him. Giving each other a smiling face and a compliment will help to bring people closer.