Now, I don&#x27;t know, but my impression is that the appearance of confidence (by which I mean the things <i>associated</i> with confidence, like being tall, speaking in a loud voice, being a guy, having a higher level of social competence, etc...)  have a lot to do with how much credit you get for doing a thing when it is obvious that credit is being shared.<p>I mean, that&#x27;s just my impression, not a study or anything... but it is something I observe, and it&#x27;s <i>weird</i> because my own bias is to assume that the less confident or less socially competent person did most of the work.