A normal IQ is essensial for sustain in the world wherein there are many impediments in nature, environment and in every culture and country. It is the story with the animals, as they too possess the same to sustain themselves with food and protection from the enemies. But man is blessed with "Dhi" the superior IQ, the wisdom which distinguishes man from the beast.
The controller of this "Dhi or the superior IQ or wisdom and the IQ levels is the planet Jupiter or Brihaspati.
The strength of Jupiter lies IN REGULATING the Mind (Moon) in the right direction. This is why in the Kalachakra, the time cycle, Jupiter is placed opposite to the Moon. No, wonder, on Amavasyas and Purnimas, the dark Moon and the full Moon nights, when the mind gets hyper-exited; only Jupiter has the capacity t be able tocontrol such such Minds. Thus on full Moon nights, when the Moon (Mind) is highly activated, Satya-Narayan (Jupiter) vrata is done.
All the knowledge is always within us, the Guru only uncovers the veil of ignorance covering our telants and knowledge. As it is, we have the same spark of Atma, the part of Super soul, the God, the source and originator of all knowledge. The guru enables the access to the source putting an end to our wanderings, sufferings and puts us on the road to increasing wisdom. This is why Maharshis could know many things through the practice of meditating and through their developed intuition. The omnipresence and omnipotent characteristics of knowledge (True knowledge- the Vedas) can only be described by the ethereal Jupiter. Jupiter has the extra-ordinary powers to tap all form of knowledge, comprehensible or incomprehensible.
Among he supporters of Jupiter, Moon is the most important as he is who exalts the Jupiter creating powerful Gajakesari Yoga, the yoga of knowledge, achievement, success and fulfillment. Thus, Moon helps in the manifestation of Jupiter and represents the Mind or consciousness. A strong Mind can only be productive, when it is under the proper guidance of supreme intellect signified by Jupiter.
Sun is the generator of all the universal energy as it is the natural significator of the Soul, the Atma. Atma contains all knowledge through Supersoul, and it requires only a good Mind and Dhi to access it. This is the source of light, which the Moon, Mind reflects. Thus an exalted and strong Sun without the malefic influences is prerequisite for a native to be an expert in multiple disciplines. As Sunlight contains all colours of light, the ray of light, which a native accesses from Sun, is dependent on the influences on the Sun. This is why the Sun represents the knowledge of Gita, which is a philosophy, which encompasses all form of knowledge and hence has all the colours.
Mars signifies the ability to break down a complex problem into smaller parts and analyze each of them to have a comprehensive understanding of the whole problem and then energetically act to get the solution. As compared to Jupiter, Mars doesn't use intuition, instead the use of logical reasoning, will to solve and strength to act in solving problem.
Mercury is the planet of intellectual skills and signifies the ability to use Language in effective communication While Jupiter signifies knowledge and wisdom, Mercury signifies formal education, i.e., application of intelligence, persuation and negotiation in solving practical problems.
Venus is a great tapasvi, the great austerities, and he rules the desire, which motivate us to learn to achieve. Thus whenever Venus is associated with Saturn (hard work and patience) and Ketu (knowledge of fine details, Mokshakaraka, for salvation), the native becomes a Tapasvi (someone who undertakes severe austerity and penances to attain siddhi). As opposed to Jupiter, who rules para vidya (meta-physics, knowledge which is used irrespective of whether we are born or not), Venus rules apara vidya (knowledge which is used in this mortal world). Thus Venus signifies practical strategies, which help in solving real life problems and achieving desired goals.
Saturn debilitates Jupiter and hence signifies loss of Memory or deviations from objectives among other significations. Saturn is a bitter enemy of his own father, the Atmakaraka, Sun and hence any studies done during Saturn Kala, will prove to be worthless. The saturn's influence on the Lagna or the 5th house, will result in making the person forgetting things and missing 1 or 2 academic years.
Rahu eclipses and debilitates Sun and also, is a bitter enemy of the Jupiter. Rahu has the strength to hide the effulgence of Sun to extreme darkness. Thus in Rahu-Kala it is impossible to gain knowledge and decision making, (due to the enmity towards "dhi" karaka Jupiter).