What Is Synastry?

An astrological compatibility analysis

In Western astrology, there is a technique called “synastry”. It is done by laying a person’s chart on top of another’s to study their interactions. In this complex web of interpersonal dynamics, a very important thing to look at is how the key factors in a person’s chart are activated by the other person. These factors may initially draw the two people together very quickly, but as time goes by, the same factors could become sources of conflicts. The charts of former US President Bill Clinton and his wife Hillary will serve as an example below:


Bill carries a Sun-Moon square in his chart, suggesting what is meaningful for him conflicts with what feels secure. To fulfil his life purpose, he may find it necessary to leave his comfort zone and support network, resulting in much uncertainly and anxiety in him. But if he continues to stay in the comfort zone, life will seem stagnant and meaningless. So how does Hillary’s chart interact with his Sun-Moon square?

The synastry grid below shows Hillary’s Saturn in Leo conjoins Bill’s Sun, hence squaring his Moon too. To him, she is very pragmatic, reliable, loyal and good at planning. In difficult times, she can give him staunch support. But she is also like a hard taskmaster for him, demanding compliance and deference. As she is critical of anything he is not done well, it is hard for him to relax and feel safe with her. So while Hillary’s Saturn provides him with concrete support, she has also heightened his already-present anxiety.

The Clintons' synastry

Bill’s Moon is in Taurus in the 8th house, indicating physical sexual contact is a main source of security for him. The synastry grid shows, however, sex is a very difficult area for the couple because Hillary has got a number of planets making hard planets to his Moon. Those from her Mars and Pluto (and Saturn as mentioned) are especially tough, for they all show Bill finds it hard to relax and be himself when with her, as there is a regular fear that he may somehow upset her.


What about Hillary? She is actually very sensitive to his moods (his Moon falls on her Descendant). If he seems awkward and tries to distance himself from her, she can sense that immediately and tempers flare up. This is because Bill’s Sun-Moon square also sets off an important configuration in Hillary’s chart, i.e. the square between the Scorpion stellium (Chiron, Venus and Mercury) and another one in Leo (Mars, Pluto and Saturn). This means in her eyes, he is often selfish, arrogant, ungrateful and has little regard for her feelings. His presence could easily trigger an inherent, buried rage in her and she feels she cannot get his attention unless she is angry. This is how a vicious cycle ensues: The angrier she is, the less safe he feels, the more distant he becomes, etc. And his extra-marital affairs certainly haven’t helped things either.


Synastry also shows the area(s) in which two people affect each other most deeply.


Figure A shows Bill’s chart in the inner circle, with Hillary’s on the outer. Figure B shows the reverse. Most of his planets fall in her 9th and 11th houses, indicating areas in which Hillary is most influenced by her husband: Foreign relations, travels and cultures, religion, philosophy, etc are all 9th house domains. The 11th house is the “house of friends” and also of social and political issues. For Bill, Hillary’s planets pack his 2nd and 11th houses (too), suggesting she exercises the greatest impact on his finances (2nd house), social circle and politics (11th).

The Clintons' synastry

No surprise for a power couple that both have deeply influenced each other’s politics, as indicated by the mutual 11th house emphasis by each other’s planets. They seem more like friends and comrades-in-arms, rather than lovers.


For Bill, nevertheless, there is clearly one area in life that without Hillary, he probably would not have made it or made it this far – Money! His 2nd house is empty by birth, suggesting this is not something he is naturally drawn to. But a shared life with Hillary who has got as many as four planets occupying this house of his makes money (and materialistic stability in general) an important concern for him in life. For example, because of Hillary’s encouragement and insecurity about finances (her Chiron, Venus and Mercury stellium in Scorpio plus Jupiter in Sagittarius in his 2nd house), he might find it necessary to develop his talents to bring in more money, perhaps particularly so at the beginning of their marriage. This is a very good example of how a long-term, intimate relationship with someone else literally changes the course of our lives.


The chief function of synastry is to help people understand where they can most easily get along, where conflicts may arise and most importantly, what inherent tendencies each partner activates in the other, that may result in a chain reaction and even a vicious cycle of relating. With awareness, both parties can choose alternative responses and stop the cycle.

Do you want to learn more? For chart-reading on synastry or even learning to read synastry yourself, check these out!:

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