The figurative use of `皮毛` is deeply connected to the cultural value of 谦虚 (qiānxū) - humility. In both academic and professional settings in China, it is common to downplay one's own expertise. Describing your knowledge of a complex subject as `皮毛` is a sign of intellectual humility and respect for the depth of the field. This contrasts with some Western, particularly American, cultural norms where individuals are often encouraged to “sell themselves” and present their skills with confidence. A Westerner might say, “I have a basic understanding of coding.” A Chinese speaker in a similar situation might say, “我对编程只懂一点皮毛” (Wǒ duì biānchéng zhǐ dǒng yīdiǎn pímáo) - “I only know a little bit of the 'fur and skin' of programming.” By using `皮毛`, the speaker acknowledges that there is a vast amount of knowledge they have yet to master. It signals an awareness of one's own limitations and shows respect for true experts in the field. Therefore, while it can be used to criticize others, it is most frequently used as a tool for polite and humble self-assessment.
`皮毛` is a versatile noun used in a variety of contexts to describe the quality of knowledge.