https://unpa.me/en-US/community/beautytip/9089223
Actually, rather than saying this is wrong, I suspect many people do it out of habit, taking it for granted. If your hair is short, ranging from a bob to a cut, it might not matter as long as it isn't severely damaged. However, the longer your hair is, the more easily it tangles, especially when wet. Therefore, combing from top to bottom can cause damage—such as stretching or breakage—in the process of forcibly untangling the hair. Consequently, for those with long hair, the optimal method for maintaining good hair condition is to comb slowly from the ends to untangle it.