Scarlett Johansson is perfect for the role of Anastasia Steele, according to American Psycho author Bret Easton Ellis, who has reportedly raised a virtual hand on Twitter to write the screenplay adaptation of E.L James' erotic fiction, Fifty Shades of Grey.

The prospect of seeing the 27-year-old Johansson in a soft, vulnerable and sexy role may be at once exciting. But is she perfect as Ana? Here are the Top 5 reasons why Scarlett Johansson will do better without playing Anastasia Steele:

1. Youth - Johansson does not fit the imagery of a soon-to-graduate 22-year-old college girl. After seeing the Black Widow seriously kick some ass in Iron Man 2 and the Avengers, her playing the role of an "innocent" young woman would only be forced.

2. The Air of Mystery - In the 2003 film Lost in Translation, the much younger Johansson pulled off a neglected young wife's vibes. She expressed longing and depression to a certain extent, and she was convincing. But as good as she is as an actress, Johansson no longer has that air of mystery that is essential in playing Ana Steele. Johansson has got sexy, fierce and feisty all over her. She is not the clumsy, stuttering Ana Steele.

3. Build - Ana Steele sees herself as plain-looking and skinny. Johansson is goddess-like sexy, but she is far from skinny. Boys certainly chased after Ana, but she does not see herself as someone with the physical attributes to snatch a Christian Grey. A woman with the looks of Scarlett Johansson should not be cast as Ana Steele because then it becomes so obvious why Christian Grey would go crazy over her.

4. The Erotic Scenes - It would be better for Scarlett to seek roles that would keep her safe from another episode of scandalous photo leaks. It's not too long ago since the actress got the FBI involved when naked photos of her surfaced online.

5. The Meg Ryan 'In the Cut' Effect - It is better for newbies and fresh faces to play the role of Ana Steele. An established actress would only risk her career, and might even suffer what Meg Ryan went through after doing the 2003 film In the Cut. It took a while before she could bounce back from the role. The story may have looked in the book, but the film presentation did not quite tell a story that was worth a movie theater's ticket.

At the end of the day, Scarlett Johansson would do well in her career with or without Anastasia Steele under her belt. The Avengers star still has to get busy with Iron Man 3 and an Avengers sequel, so why bother?