There are several ways of lying. You can simple not give any info, you can lie as a habit and you can twist the facts. Here are a few ideas about Mercury's aspects and the effects, with examples.
To start with slow answers, I know persons who speak the truth very very slowly, mostly because of a desire to be as accurate as can be. They are not lying, then. Most of them are specialized educated persons who are aware of the impact of what they say or of the responsibility that they have as an official spokesman. That is why they are careful and that is why they like to limit themselves to established facts only. It is the Mercury-Saturn-effect with a lot of 'uh's' between the words:) Of course, Mercury-Saturn CAN be an aspect that reflects lying. Saturn happens (...) to be the symbol of time...and of restrictions. You just don't tell it all, sometimes because it is not official, or allowed or decent.
Statistics often don't work the 'other way around' and sometimes tests in artificial situations are not similar to the effects in the real world. Sometimes slow answers are true. A certain percentage is just thinking before speaking: the Mercury-Saturn effect. In fact, some of those Mercury-Saturn-speakers deliberately hesitate to make the other aware of the importance of the answer!:)
Read more about Mercury-Saturn on this blog Astropost!
Science and Mercury-Saturn
Mercury-Saturn, just thinking...
Moon-Mercury lies are the lies you tell because they are being expected in your group. You simply adept your story to the public. The Moon-Mercury lies are the every day, common lies. The way you behave shows that you are lying when you have a Moon-Mercury (= emotions-brains) conflict in your chart. Sometimes it is very obvious. Then you shake your head saying yes, for example.
Only in serious case there might be a habit (Moon) of lying (Mercury). For example, Joran van der Sloot is known for his incredible changing stories and if he was born in the morning, his Moon is opposition Jupiter and inconjunct Mercury. Or what about the case of Josef Frizl? This man has Moon square Mercury (and Mercury at Aries Point).
Mercury-Mars is speaking too fast and too soon, sometimes it lead to stutter and sharp words in discussion. People who work with words often have this aspect in their natal chart: words are being used Mercury-Mars is about information used as a weapon: and of course you only select the sharpest and fastest ones.
Example of Mercury-Mars and Mercury-Uranus aspect:
Chart of Samuel Huntington
Mercury-Jupiter's effect is that the message is exaggerated in order to convince the other. Big mouths, big words and sometimes great ideas are born with Mercury-Jupiter contacts in the sky. The other side is that the receivers of information tend to notice that too many words are being use to convince them. The vocabulary is large, always. Take for example Barack Obama, who is a great speacher. He has Mercury opposition Jupiter(1).
Read also about Joran van der Sloot's Mercury-Jupiter
Mercury-Uranus' effect is 'hectic' as the combination means 'information on impulse' (re: Mars-Uranus for acting on impulse) and provocative information (just a little different from what the others think). Uranus is the planet of change and Mercury of info, so lies of the Mercury-Uranus-kind are quick lies and often communication techniques like changing subject when it comes to telling the truth or at worst by twisting words and facts to end up with a completely different story.
Prominent Mercury's and Uranus are in the charts of David Cern`, artist and Hitler.
In the scientific test mentioned above, fantasy was used and the symbol of fantasy is Neptune. Neptune is also the symbol of what is 'unlimited'. And fake. Mercury-Neptune hides facts (remains silent), invents facts or simply misunderstands the information and is confused. Lying with a Mercury-Neptune is easy and is done by giving misty information or by 'pretending' facts.
Sometimes people with a prominent Mercury-Neptune combination in their charts become the victim of false information or others simply don't believe what they are saying because it sounds like if the person is inventing it (thinking too long, known for having a fantasy etc....). When you have to invent stories because you are an author, this aspect can be a blessing, but in real life it is not easy. For an example, see the charts of Gerard and Guillaume Depardieu. BTW, Brad Pitt (actor) has Mercury sextile Neptune, tightly.
More about Mercury-Neptune on this blog Astropost:
about the Friedman case.
Mercury-Pluto's effect is that in order to impress the audience facts are being manipulated (for the stronger effect), a sort of communication strategy that makes the receiver of the message feel uneasy. Often the information is 'inside' information, by an expert or a politician. In few cases this aspect reflects the possibility of the power of words and knowledge (dangerous information). Example?
The author of James Bond..., Ian Fleming, who was the personal assistent of the Director of Naval Intelligence of the Royal Navy in World War II. He was telling 'strong stories' with inside information.
COMBINATIONS OF ASPECTS WITH MERCURY
Combinations of aspects or midpoint combinations with Mercury alter the interpretation or give us more insight. Take for example the late Dutch prince Bernhard with Mercury conjunct Pluto and inconjunct Uranus for very strong and controversial (political) opinions. This combination also reflected his traffic accidents. Sometimes he just wanted to be too fast.
MERCURY AT WORK
About Mercury and the profession, see my site Astromarkt...
(1) Barack Obama's Mercury is related to more objects in the chart, by major and minor aspects: a septile with Mars, opposition with Jupiter, half semi square with Uranus. This combination can be interpreted as the combination of an inventive (Jupiter-Uranus) debater (Mercury-Mars).