Samuel Langhorne Clemens / Mark Twain: Are his diverse signatures typical of a person with a famous pseudonym or indicative of multiple personality?

Here is a link to twenty of his handwritten letters:

http://twain.lib.virginia.edu/sc_as_mt/yrstruly.html

He signed his name in seventeen ways:

 1. Marcus

 2. Mark

 3. Mark Twain

 4. Mark Twain / (SL. Clemens)

 5. Mark Twain / Samuel Langhorne Clemens

 6. Sam

 7. Clemens

 8. SLC

 9. S. L. Clemens

10. Saml. L. C.

11. Saml. L. Clemens

12. Saml. L. Clemens (“Mark Twain”)

13. Saml. L. Clemens (alias) Mark Twain

14. S. L. Clemens Mark Twain

15. Samuel

16. Samuel L. Clemens

17. Y

In multiple personality, handwriting and signatures might vary from one personality to another. Two personalities might use different spellings of the same name. I don’t see anything definitive in the above, but perhaps you are a graphologist or have known famous people with pseudonyms, and are in a better position to judge.