Astrology compatibility keeps in mind many different factors, but the baseline you usually start with is compatibility with your Sun sign. This often means you're told that you'll be most compatible with the other signs of the same element as your Sun sign. But sometimes, that isn't the case for you, and you may find you often can't stand others of that sign. So what can explain this astrological incompatibility?
Basics of Compatibility: The Elements
Using elemental compatibility is a bedrock of astrological compatibility. Zodiac signs of the same element have the same base energy, and this gives them a very natural, easy understanding between them. The fire signs are energetic, the earth signs are practical, the air signs are intellectual, and the water signs are emotional, and generally speaking, signs of the same element just get each other.
In case you're unfamiliar with the elements and signs, they are:
Fire - Aries, Leo, Sagittarius
Earth - Taurus, Virgo, Capricorn
Air - Gemini, Libra, Aquarius
Water - Cancer, Scorpio, Pisces
But it's more than just Sun sign!
First, you need to understand that compatibility is more than just based on what's compatible with your Sun sign - WAY more! You have to assess all of the planets and houses (and asteroids and other positions) in your natal chart to get a full picture.
Often, we're most compatible with those we have a Moon connection (since the Moon is our emotional self), a Jupiter connection (creates genuine like between you), a Venus connection (who rules relationships), and a 7th house connection (also rules relationships). If these points in your natal chart are in a different sign from your Sun (usually the case), and a different element from your sign, then you're probably going to be more compatible with different signs from your Sun.
So what about when you actually can't stand a certain Zodiac sign?
Normally, you do tend to get along, at least on a base level, with the Zodiac signs of the same element as your Sun sign, even if they're not the most compatible to your Moon, Jupiter, Venus, or 7th house. But sometimes that isn't the case, and you may find that whenever you encounter someone of a certain sign, they get under your skin.
(I want to note that I am NOT talking about when one person hurts you and you use that as an excuse to hate on everyone of that sign - that's YOUR problem, not an astrology problem)
There are a few points in your natal chart that, if you connect with someone of that sign, you maybe can't take them. First is going to be your Saturn sign, and this is because Saturn is a restrictive planet. You may feel very restricted around these people, limited, judged. Saturn always has to be considered carefully when gauging compatibility because it can help with long-lasting relationships, but if it's too strong, it can kill it before it ever starts.
Another one may be your Pluto sign. Pluto rules power struggles and control issues, so we can see that play out when someone connects to your natal Pluto. You just butt heads and fight-fight-fight, and it's rarely light at all. At the same time, Pluto can generate major heat and passion between you, so it can be difficult to walk away from, which ends up making it more unhealthy. Pluto connections often need to be balanced with lighter connections, otherwise it can go very, very bad.
A third would be your Chiron sign. Chiron is ruler of wounds, so a Chiron connection can actually create more wounds in your life, and you may find there's a lot of mutual hurt between you. Chiron connections can help with healing though, but this usually is only the case when you've already been doing that separately and you come together in a better place. If you're both still a mess when you come together, you'll usually make it worse for each other.
A surprising one would be your North Node sign. This is surprising because your North Node is a positive position showing your potential and what you should grow into in this life for ultimate life fulfillment. But, it's unfamiliar and uncomfortable because we haven't learned it yet, so often, when you encounter someone who connects with your North Node, it's an uncomfortable connection. Once you learn your North Node and manifest it properly in your life, that can change, and you can find your North Node connections help you grow even more. But until then, it's total discomfort!
So, these are just a few instances where you may feel incompatible with a certain sign. Good luck in your relationships!
Suggested Reading: The articles in the Love Astrology Series for Mars, Jupiter, Saturn, Uranus, Neptune, Pluto, the 12th house, Chiron, eclipses, retrogrades, the Asteroids of Your Name, and the Lunar Nodes