Found this while researching for Monday's decal course...from
http://www.sff.net/people/Saswann/text/wb.htm Aliens aren't human beings
Star Trek to the contrary, a good SF alien is not a neurotic human in makeup. An alien should be different, and different in a way that is consistent with its planetary environment, its evolutionary history, the culture it comes from, and its own personality. Each of those developmental factors feeds into the next in a descending hierarchy that results in the being's behavior, and each should be consistent to the prior. Even subtle differences in the evolutionary history (assuming all things being equal) will lead to wholesale changes in the culture an intelligent species develops. It is probable that we cannot truly write from an alien point of view, but we can develop our alternate people in a logical consistent manner. If you want to write an alien that is different in some specific manner from us, then work to find an evolutionary reason for its difference (why it would aid the species' survival, or the survival of its evolutionary progenitors) and create a homeworld where such developments make sense.