Synastry vs. Davison: A Relationship Astrology Technique Comparison
Description of Techniques
Synastry is the comparison of two or more natal charts, and how placements between two people manifest in their interactions and lives. The biwheel drawing makes it easy to see aspects formed between charts, and whether or not you use synastry, the concept of chart overlays is a foundation of all astrology. Synastry is a great next step to study after natal astrology, as other people’s placements can act as permanent transits to your chart, provoking or exciting you, and often both!
Composite charts are another form of comparing natal charts. The Composite chart was created by John Townley, who popularized the method in his 1973 book The Composite Chart. The idea is that you calculate the midpoints of each person’s placements to generate a hypothetical chart that characterizes the relationship. More attention is paid to the ascendant, the sign placement of the chart ruler. and stelliums in houses and or signs to describe the themes of relationships. However, you cannot over-interpret the chart since it is largely based on midpoints. Transits can be applied to this chart to assess how the astroweather is affecting a relationship.
In the early 1970s, Ronald Davison developed and outlined a different form of composite chart that would become known as the Davison Relationship Chart. Unlike the midpoint composite popularized by John Townley, the birth date, birth time, and birthplace are averaged to generate a chart that exists in time and space. Many of the same principles for interpreting midpoint composite charts apply, but it can be read like a natal chart. Experimentation suggests that timing techniques beyond transits can actually be applied to this chart, describing the seasons of a particular relationship.
Mo’s Preference: Davison
I am a big composite fan, and more specifically a fan of the Davison Relationship Chart. People understand their connections to other people through their experience of the relationship, and I think both forms of composite charts are helpful for achieving these goals. A big selling point for me with Davison charts is that you can identify the midpoint of a relationship in the ephemeris. Since the chart generated is not just the midpoint of individual placements, you can have retrogrades show up in the chart. If you are connected to someone born in a different part of a key planetary cycle, you may find that a retrograde planet or a cazimi plays a central part of your relationship. You may also find repetitions of that planetary cycle (eclipse, retrograde, cazimi, etc.) are transits that strongly impact the relationship! Overlays are key, and despite having an averaged date/time/location, sometimes the energy of one person dominates more in these charts, rather than being a perfect average. This provides valuable interpretive nuance, regardless of the nature of the relationship!
Anna’s Preference: Synastry
Synastry always gets a bad reputation as a sort of lesser form of astrology for a few reasons. Relationship astrology is sensitive and extremely complex, as well as personal. It’s easy to think you’ve got it wrong because there are so many astrological and emotional variables. I honed my astrological skills through dissecting my own relationships and those of others, vascilating between the roles of observer and participant. As I study and read astrological texts from both the ancient and modern world, I’m always pleased to see synastry woven into descriptions of nativities and other delineations. While I also use Composite and Davison charts for relationship readings, because they were crafted in the 20th century, there isn’t as much of a richness of historical analysis, and much of that analysis comes from synastry as well.
As astrologers understand more about the ways that the stars manifest in overarching societal experiences, mapping out the sparks in your romantic connections may seem petty in comparison. But amidst all of the turmoil and crisis of humanity, it matters who you come home to, and a synastry biwheel can show that so simply and poetically. I think there is something to be said for the basic and vital aspects such as Venus trine Moon, which expresses such care and understanding between individuals.
Finally, synastry is not just for romance! Rivalries, friendships, families, career, social media accounts, and pets are all relationships that can be examined through synastry.
About the Authors:
Anna DunLany is a traditionally influenced modern astrologer who specializes in natal and relationship readings. She started studying astrology in her teens, reading every book and internet forum she could find, then formally studied with Samuel Reynolds, and opened her professional practice in 2022. With her background in non-profit fundraising and volunteer management, Anna is focused on how AYA can best support astrologers educationally and financially, while connecting with one another in meaningful ways.
A deep love of history, creative writing, and her Gemini MC led Anna to combine her academic and esoteric interests and write her newsletter, Overly Personal Astrology, where she writes personal essays and astrological analysis of herself and historical figures. She lives in Atlanta, Georgia.
Mo is an American astrologer currently based in Toronto, Canada. She has been a practicing astrologer since 2018. She specializes in Hellenistic and Medieval astrology, focusing heavily on Solar Revolutions, Profections, and related timing techniques. She is passionate about teaching people about the various applications of the smaller subdivisions of the zodiac.