The presence of Mercury in the 4th house makes the native’s mind focus on his home and his family. This placement creates a person who is very interested in researching the traditions; both of his family and of his nation, religion and culture. His childhood years are based on communication, while also usually gives working from home.
The fourth house is ruling the less dominant parent (usually the mother), and Mercury makes her have a strong Gemini/Virgo emphasis in her natal chart. This makes her rather talkative and her behavior encourages the child to talk from a very early age. Both she and the father are well-educated and offer to the youngster a very comfortable atmosphere for developing his intellect. They usually have a library at home and the child has direct access to many books and information. There are possibilities that at least one of the parents is a teacher, or elsehow involved in a profession that transfers knowledge and information. The parents dedicate a lot of time in educating him, and make learning something he starts to love.
The native’s home becomes a good environment for reading and studying. When he grows up he understands how much he owes to his parents and will probably create the same type of surroundings for his offsprings too. The tradition of discussions during lunch time is something that is passed from generation to another, in such types of families. Also, the parents use a lot of other kinesthetic stimulants for the child’s education, such as puzzles, table games, riddles and other.
As the fourth house is ruling one’s residence, the fast motion of Mercury might bring frequent moving to other houses, while at some periods the native might even live in hotels or at friends. There are possibilities of this happening for professional reasons, or even that his job sends him to other towns for special projects that he is involved. Another possibility that this natal placement brings, is working from home (or at least doing a part of the job at the native’s residence). Such people will frequently create an office in their house; the room will be full of books, quiet and perfect for intellectual work.
The individual with such a placement will adore digging the roots and the traditions. He might be interested in researching the genealogical tree of his family, the traditions of his country and the writings of religions. There is a strong attraction towards history, archeology, geography and ethnology, while if Mercury is strongly connected to the 9th house the native will late in life get involved with publishing about these subjects. This type of intellectual work is one of the native’s preferred amusements: Sitting in his office, drinking his beverage and dedicating his time to knowledge up to the late hours can be even better than a Friday night out.
As the fourth house rules property and real estates, the native may follow professions connected with asset management or real estate finances, while also could be running the financial part of a family business (not necessary his own). This has a lot of possibilities to happen when the 10th house cusp is located in Gemini or Virgo.
With Mercury in the 4th house (and the Sun also probably somewhere near), the native is firmly attached to the culture he grew up in, having big difficulties to adapt to other cultures, religions and ways of life. He will prefer to never leave his birthplace or country, and even if he is forced to do so his mind will be constantly focused on his home. Nostalgia and even depression will be the obvious effects; sooner or later he will find the way to go back to where he feels he belongs. When Mercury is adversely afflicted, the native can be really closed to new ideas; this can lead even to traditionalism and fanaticism. Whatever is new can be viewed as a threat to the order he has in his mind, and he does not really support the modern way of life.
Overall, this Mercury placement is a very good one; the only things one should be careful while having it is becoming overly fanatic about the things he knows (or believes he knows). He should try to be a little bit more flexible about his beliefs and understand that the other people have their own roots too- and most probably they are quite different than his.