[Raphmedia]

It's only one of the definitions. If anything, it's the common one instead of being the scientific one.

http://www.dictionary.com/browse/introvert says:

"introvert

noun

1. a shy person.

2. Psychology. a person characterized by concern primarily with his or her own thoughts and feelings (opposed to extrovert ). "

[reddit_clone]

No (2) doesn't sound right. It makes it sound synonymous to 'self centered', which I am sure most introverts are not.

[sp332]

Your "own thoughts" don't have to be about yourself. It just means you're paying less attention to what other people think or feel.

(edit: added "don't")