egotistic
She was egoistically concerned only with her own preservation.
The author believes that we are biologically programmed to act egoistically.
It is egoistically rational for people to care about their own future rather than anyone else's.

SMART Vocabulary: related words and phrases

Showing arrogance and conceit
(as) proud as Luciferidiom
airs and gracesidiom
arrogant
arrogantly
as if you owned the placeidiom
egoistic
egomaniacal
egomaniacally
egotistic
egotistically
patronizingly
pomposity
pompous
pompously
popinjay
swollen head
swollen-headed
talk down to someone
think the (whole) world revolves around youidiom
throw your weight aroundidiom

You can also find related words, phrases, and synonyms in the topics:

Selfishness