The houses are connected with the zodiac signs, Aries the first house, Taurus the second, Gemini the third, etc. In my opinion, the house that rules your first house, also known as the Ascendant, is the most important house in your chart, because from there, it houses the different placements of the signs, planets, and houses. To figure out what your 12th house is in, you must know your ascendant. So, to answer your question, yes, the house sign and a heavy star placement in that house is influential, but to the degree, the type, it is very hard to pinpoint. You could be very piscean, because of a strong 12th house, but depending on your 12th house placement in the sign and the cusp, it could vary. 12th house is hidden, in my opinion, it is the house of secrets, intuition, and self sacrifice. Pisces is a sign of self sacrifice, a great adventure.