We analyzed a mechanism to alleviate aggressions on computer mediated communications. A title that supposedly reflects the user's behavior or status, such as calm, expert, optimist, or aggressive is displayed on the screen. Two types of title generation, title reflecting and not reflecting exact aggression level, are compared to the case without title using laboratory experiments, where participants select comments to be posted after reading the topics of discussion and other participants' comments. The results indicate that displaying a title that is unrelated to the aggressiveness of comments posted by the user is equivalent to displaying a title based on accurately calculated aggression level of comments. Therefore, simply displaying their titles to users is effective to reduce aggressiveness of their comments in pseudonym type computer mediated communications.