In astrology zodiac signs have given title according to their natural karakattwa which are given below :
Zodiac signs are divided into four Varna(caste) which are Brahman, Kshatriya, Vashya and Shudra.
Cancer, Pisces and Scorpio are a part of the Brahmana Varna.
Aries, Leo and Sagittarius are a part of the Kshatriya Varna.
Taurus, Virgo and Capricorn are a part of the Vaishya Varna.
Gemini, Libra and Aquarius are a part of the Shudra Varna.
Now let’s say if moon is in Taurus, Virgo, Capricorn makes a person materialistic, stable, money oriented, business minded, Status oriented, Critical, perfectionist which indicates Vaishya Varna.
If Moon is in Aries,Leo or Sagittarius person will like independent, warrior, creative,aggressive,energetic,fighter, enthusiastic, dutiful which indicates Kshatriya Varna.
If Moon in Gemini, Libra or Aquarius person will be confused, dual minded, intelligent, knowledgeable, inquisitive, helpful, serving others, social reformer, social which indicates Shudra varna.
If Moon is in Pisces, Scorpio or Cancer person will be highly imaginative, always live in the past, helping nature, serving others, scholar which indicates Brahmin Varna.
I have taken the moon because Moon is the planet which represents emotions our internal feelings, what we feel inside.
Note- The Varna Vichar more often is used in Horoscope match making these days.