I would hypothesize that the correlation is that a pseudonym increases your sense of invincibility. If you already think there will be no ramifications of frie

I would hypothesize that the correlation is that a pseudonym increases your sense of invincibility. If you already think there will be no ramifications of friends/people knowing your opinion, then a pseudonym doesn't give you much incremental benefit. If, however, the potential ramifications are great, a pseudonym does a lot to distance the ramifications from you individually.