One of the things you can tell in the natal chart is how a person learns. While there are few absolute indicators of high intelligence, it is easy to delineate how a person learns.
If we consider the classic examples of high intelligence, what we are actually seeing are indicators of how well a person communicates his or her intelligence in a way that is easily perceivable to other people. Having the air signs prominent, especially Gemini or Aquarius, certainly gives one the natural capability to learn well and quickly as they love dealing with information. A strongly placed Mercury and even Uranus can also indicate that a person may be of high intelligence. However, this doesn‘t necessarily mean that a person communicates this well to other people. Albert Einstein, for example, was never lauded as a genius until he published his theory of relativity. A look at his chart shows no classic indicators of high intelligence. In fact, with Saturn conjunct Mercury, it may seem certain that he will be a slow learner who may not retain much.
Or that learning slowly and deliberately is a key here. He has one planet, Jupiter, in an Air sign and the north node as well, opposing Uranus. This is someone who can think slowly, deliberately, and conscientiously without communicating it verbally and entertain wild, expansive thoughts. He may have learned quickly, but allowed it to sink more deeply.
How do you learn? One indication is where Mercury is in relation to the Sun, whether behind it or ahead of it in the chart. People with Mercury ahead of the Sun tend to learn slowly but in a more shallow way; they have to continually use what they learn in order to really master it. People with Mercury behind the sun tend to learn more slowly but more deeply, and over time, come to naturally master the material learned. This does not bode well for young students, but once one has the freedom to study at his or her own pace, blossoms. Can you guess which one is more likely to get good grades in primary school?
What house and sign is Mercury in? This is not only what you like to learn by subject, but how you approach learning. Mercury in Scorpio likes to probe. Mercury in Leo likes to show off how much it know. Mercury in Aquarius likes to make radical ideas Mercury in the 6th house likes to organize information. Mercury in the 7th house likes to share information with someone. Mercury in the 3rd house likes to share information with everyone else, and Mercury in the 10th house seeks out information and feedback from superiors and authorities.
The next thing to look at is the sun itself. What sign is it in. This is the information you like to take in, because it how you like to place yourself in the world. Someone with a Taurus sun likes practical information that can be used in the immediate future. A person with an Aries sun likes information that leads to action and fulfillment of ambition. A person with a Pisces sun tends to like to absorb all of the information around him or her and to distill it to oneness.
The next thing to look at is the rising sign. It is a lot like the sun sign in how it deals with information, but differs in the way it gets information. The rising sign is how information comes to you. Whereas the sun seeks out information, the rising sign indicates how information is presented to you. Gemini Rising folks can handle a lot of information at once, Virgo risings are adept at filtering out extraneous information and describing the details, and Libra rising folks can find the balance in the information given. Pisces folks are often overwhelmed by information and need to let it all absorb and then will suddenly get it, completely. Of course, the rising sign is personal, so the perception of the information is personal: whereas Gemini Rising is fine with a ton of information at once and sees it coming in a continuous line, in that same experience, Pisces rising will see this as a confusing mess. This is because Gemini can easily string together bits of information, but Pisces needs to know that there exists a whole that the pieces will fit into, universally. Sagittarius rising needs to know that information serves a higher purpose or they simply won‘t give it a second glance — there is always more information out there to learn.
Where it Mercury in relation to the Ascendant? Are they both in the same element, such that they are trine? Then, the mind is able to manipulate the information received more easily. What if they are square? Here, there may be more of a struggle to integrate information. An opposition, on the other hand, is quite interesting, as the native may be compelled to seek out another party to tell them what to think, or may be compelled to regurgitate what is received in a totally different manner.
Can you share what you have learned with ease? This is usually shown with Mercury in a natural house (3rd usually, but also 6th, as these folks tend to demonstrate their knowledge well). Look at the house where Mercury is to determine how you demonstrate what you know. 12th house Mercury speaks in secret or goes straight to the heart of the matter. 9th house waxes philosophical. 10th house is a bit bossy. 11th house prefers humor. 2nd house communicates deliberately and with economy. 8th house tends to speak in code and only lets it flow when really comfortable. 7th house tries to get you to agree or tell you what you want to hear. 5th house tends to find ways to make it fun. 1st house lets it flow like an aria of diarrhea. Whatever that means. 4th house tends to be nurturing, nearly patronizing, when they speak.
Keep in mind that no condition of Mercury negates another but enhances, exacerbates, or augments it. The key to chart synthesis (which will take practice, so worry not) is to take all the pieces as valid and put them together in a cohesive manner. A person who has Jupiter conjunct Mercury in 12th house Capricorn is not a living, breathing paradox, not entirely, that is. If we put it together we might come up with someone who prefers humorous (Jupiter) communication (Mercury) and likes to do it a lot (conjunct) but tends to do it sparingly, in a deadpan manner (Capricorn), in a way that is unseen right away. Hm…what could this be? Let us search our minds for what kinds of people communicate in this way. Perhaps this person is the perfect straight-man in a comedy duo, and with that Aquarius rising they probably have and the Leo descendant (the partner is the attention-getting clown), it is entirely possible that this person could aspire to be a comedian just like that. Teller from Penn & Teller comes to mind, as Teller never speaks but sets up all of the gags.
Now, do not forget the Sun here, as Mercury is only within 60 degrees max of the Sun. Since all of the signs and the houses tend to flow into each other, the sun will be within a similar flow to Mercury. If this comedy straight-man has the Sun in Aquarius in the 1st house, he or she might be the one trying to steal the show (or acting like it, at least), but really lending his or her talent to the friend (Aquarius) who is the star (Leo). If he has the sun in Capricorn, perhaps he is more somber, like the straight-man ventriloquist who always ends up the butt of the dummy‘s jokes (which makes sense with 12th house Mercury, as he or she speaks in secret), or prone to unintentionally comical attempts at putting on airs (like Hardy from Laurel & Hardy). If the sun is in Sagittarius, this person may communicate in a more self-righteous or philosophical way, like W.C. Fields. Ever notice how his persona seems to want to be this lofty, philosophizing straight man but can‘t quite pull it off because it lacks so much awareness (12th house-type mind) and hilarity ensues?
In a culture in which learning is often considered to be a linear experience in which one goes from A to B and then to C, it is entirely possible that there are many people out there who simply flounder at this conventional, not creative approach and don‘t quite make the grades they want or do and hate every moment of it. Learning is actually a subjective experience, and one asset of using your chart to figure out how you learn is also learning how to augment whatever material you must learn so that it fits your learning style.
For example, I can‘t deal with a flood of information that comes from no where and seems to belong to nowhere (Pisces Rising). Math outside of science, economics, or the discipline that it is the language of makes little sense to me. I must discuss it broadly (9th house Sun) and philosophize on the abstractions (Sun in Sagittarius). However, I have a hard time repeating succinctly and accurately what I want to say and write much better than I speak (Mercury retrograde). However, I have a tendency to be blunt and probing (8th house Mercury) and say things that seem to come from left field or seem contrarian (conjunct Uranus). I need to know the darker implications of not doing the recommended thing (Mercury in Scorpio). I cannot understand the small thing I must learn without knowing how and why it fits into the big thing and what the possibilities are, and how far the limits stretch. However, I do well with noticing and applying practical application of details (Mars and Jupiter conjunct in 6th house Virgo). For me, less formal instruction (Mercury retrograde), more doing (Mars in Virgo), and more experimenting (Mercury conjunct Uranus) on my own time, in the quiet, where I can read and be lost in my own mind (Mercury behind the Sun) is how I learn, and then one day, I just suddenly get it (Pisces Rising) and when I am ready, I feel the compulsion to share it with others (9th house Sun again). Not exactly easy, but I thrived in college and I have found that, for the most part, it is helping with law school, even if my classmates think that I‘m odd (recently, in Torts, I was the only person who knew why haystacks spontaneously catch fire sometimes. Oh, the things you learn dabbling in animal husbandry).
However, I do have a class that is being taught in a more conventional manner – Civil Procedure – and I am only now getting the hang of it because I have to take the time to re-teach the material to myself. While I understand that a lot of students are more comfortable with doing less case briefs and doing more conventional things like multiple-choice quizzes, this is where I get lost. Multiple choice tests are very confining – I hated the LSAT – confuse me. I also hate that in this class, unless the question is strictly about the material we have just covered, it is not welcome, which is a bummer for me, since I need to see the dimensions of something by testing the limits. So, I stopped asking questions and look up whatever I want to know on my own time. I jump through the hoops I need to jump through then learn civil procedure in my own way. It takes more time, but I may finally get the hang of it by finals.