This is not always true. But I have the feeling that people of water signs and fire signs are more likely to conceal the truth to protect their self interests. For example, O.J. Simpson was more likely to have covered up to avoid punishment while Michael Jackson was more likely to have told the truth as he knew it when faced with accusations.
This is not because people of water signs and fire signs are less moral. Rather, it is because they are more afraid of being confronted and having to provide an explanation, which they do not have as much courage for as people of earth signs and air signs do. Avoiding confrontations does help them reach their goals faster. That is why they are more likely to succeed in business and politics which often require speedy executions.
Another reason for people of water signs and fire signs to cover up more may be that they are more into self-protection and less into altruism as compared to people of earth signs and air signs.
With that said, there are plenty of exceptions. Conclusions in horoscope are never absolute. For example, I have said that people of water signs tend to have more respect for the powerful. But there are people of water signs who dare to speak truth to power too. I just read an article on the Gates Arrest on time.com by Lawrence O’Donnell, who is a Scorpio, and I see that he did not look down on professor Gates or try to defend the police. Jim Garrison, Democratic District Attorney of Orleans Parish, Louisiana, who is also a Scorpio, is the most daring I have ever seen. He dared to tell the truth and were not afraid of the most powerful people in this country. I did not expect such personality traits in a Scorpio. To explain this, I will have to say that Lawrence O’Donnell and Jim Garrison saw that the Presidents of the United States deserved the most respect. But still, it is undeniable that those who were against the Presidents were the most powerful people in the United States.