Two factors that cause egocentrism are "the personal fable" and "imaginary audience".

Personal Fable https://en.wikipedia.org/wiki/Personal_fable

Thinking of himself or herself as the center of attention, the adolescent comes to believe that it is because he or she is special and unique. Feelings of invulnerability are also common.

Imaginary Audience https://en.wikipedia.org/wiki/Imaginary_audience

A state where an individual imagines and believes that multitudes of people are enthusiastically listening to or watching him or her.

Here's an interesting journal article these two states http://file.scirp.org/pdf/PSYCH20120600004_86330162.pdf

Females tend to exhibit more imaginary audience ideation than males, as has been shown in a quite large number of investigations.