In "Alien", is there any reason given as to why Ripley goes back to retrieve Jones the cat before launching the self-destruct sequence?

There are lots of folks out there offering up opinions, however, within the movie itself, I do not believe there was a definitive reason given.

Here are a couple of guesses:

1. Ripley shows emotion in the original, feminising her, she goes back for Jonsey the cat for example.

2. Remember at the end of the movie "Alien", Ripley is about to escape being ripped apart by an alien monster when she realizes that she has to go back for her freaking cat? That is the "Ripley Decision" - it takes place whenever a main character decides to risk their lives for a pet.

http://www.bellaonline.com/articles/art60828.asp

http://deltorofilms.blogspot.com/2008/02/save-cat-or-die-horrible-death.html