it was found that high-power subjects also tended to assume other people had the same information that they had (the "telepathic boss" problem - the boss assumes that everybody knows what he knows and want). They were also less accurate than low-power subjects at judging emotional expressions. There were also anticorrelations between reports of general feelings of being in power in one's life and tendency to take other's perspective. Overall high-power people seem to anchor too heavily on their own vantage point and this impairs their ability to consider what others see, think and feel.
In general power bias would make the empowered people tend to think they have more support from others in their views than they have. Altruists in power would be even less concerned with individual variations in goals and values - i.e. they would tend to become more egalitarian and paternalist. Egoists in power would become more concerned about the ambitions of others, i.e. paranoid.