First of all, the smile from the heart will wrinkle the corners of the eyes, but the smile can't affect the muscles of the corners of the eyes. Even if it does, it is stiff and fleeting.
Secondly, fake smile can be maintained for a very long time, because it lacks the intrinsic motivation of real emotion, so it is difficult to know when it will end. Moreover, there are often inconsistencies between eyes and mouth, facial expressions and body movements.
Thirdly, for most expressions, the sudden beginning and end indicate that people are consciously using the expression.
Finally, when you smile, the expression of the two cheeks is often asymmetric. People who are used to using the right hand pick the left corner of the mouth higher, while people who are used to using the left hand pick the right corner of the mouth higher.
Several ways to recognize fake smile
The address etiquette in the foreign communication? - She Wai Jiao Wang Zhong De Cheng Hu Li Yi
Birthday toast of leaders - Ling Dao Sheng Ri Zhu Jiu Ci
Notes on drinking water at Chinese banquet - Zhong Can Yan Xi Yin Yong Jiu Shui Zhu Yi Shi Xiang
Identify the other person's psychology through verbal posture - Tou Guo Kou Shi Shi Bie Dui Fang Xin Li
Pass the Secretary pass by the rule of plea for help - Yong Ken Qiu Bang Zhu Fa Ze Tong Guo Mi Shu Guan
Build a bridge of friendly relationship between mother-in-law and daughter-in-law - Da Jian You Hao Po Xi Guan Xi De Qiao Liang
Using "heterosexual effect" to build network - Li Yong Yi Xing Xiao Ying Da Jian Ren Mo
Be good at getting close to others - Qiu Ren Ban Shi Yao Shan Yu Yu Ren Tao Jin Hu
Grace and power to subordinates, let subordinates work for you - En Wei Bing Shi Yu Xia Shu Rang Xia Shu Wei Ni Ban Shi
Remember what your boss says occasionally - Lao Ji Shang Si Ou Er Tu Lu De Hua
When persuading others, avoid official voice and official tone - Shuo Fu Ta Ren Shi Ji Guan Qiang Guan Diao
Clever use of fund conversion to save costs - Qiao Miao Li Yong Ji Jin Zhuan Huan Jie Sheng Cheng Ben