egoistical

1. I have always been aware that I am by nature self-absorbed and egoistical;
   一直以来，我也意识到我会自然而然地以自我为中心。
2. Under some conditions, altruistic individuals are more apt to evolve than those egoistical individuals.
   在某些情况下，利他的个体比利己的个体更有利于自身的进化。
3. Ethical egoistical behaviors have a clear direct effect on brand equity attenuation and cast an indirect effect on brand renaissance difficulty;
   利己主义营销行为对品牌衰减影响显著，并对品牌重生难度产生间接影响；

adj

1. limited to or caring only about yourself and your own needs

   Synonym:    egoisticegocentricself-centeredself-centred