A pronoun that ends in self or selves is either a reflexive or an intensive pronoun.
Notice: that if you drop the reflexive pronoun, the sentence no longer makes sense. (Ben Carson dedicated to becoming a doctor.)
An intensive pronoun emphasizes a noun or another pronoun within the same sentence. Intensive pronouns are not necessary to the meaning of the sentence.
- You yourself have overcome many hardships.
- Dr. Carson himself has survived great poverty.
Avoid the use of hisself and theirselves, which are grammatically incorrect. Use himself and themselves instead.