Why did Enron's culture encourage fierce competition, not only among employees from rival firms, but also among Enron employees themselves?

The changes that Enron and more recent corporate scandals have brought about in public expectations for corporate management and their accounting firms to establish, follow, and enforce a professional business code of ethical standards.  Your thoughts!

What caused the Sarbanes-Oxley Act to come into existence, and evaluate the attitudes and behaviors that created the failure of Enron