1.Conditional clause: "It depends on the individual, as personality and upbringing significantly influence whether someone is selfish" uses a conditional clause to express the dependency of selfishness on personality and upbringing, adding complexity to the sentence.
2.Complex sentence structure: "Intelligent individuals, like anyone else, can exhibit both selfish and selfless behaviors" uses a complex sentence structure with a parenthetical phrase "like anyone else", enhancing the depth and richness of the expression.
3.Noun phrase as subject: "Selfishness is a multifaceted trait" uses a noun phrase as the subject, adding emphasis and clarity to the statement.
4.Prepositional phrase as adverbial: "as it involves a complex interplay of various factors" uses a prepositional phrase as an adverbial to explain the reason, adding complexity and depth to the sentence.