The astronomy of this body links it to both Pluto and Chiron. All three have extremely eccentric orbits that cause them to cross the orbits of major planets. In fact, prior to the discovery of the Centaurs, Dr. Brian Marsden of the Smithsonian Astrophysical Observatory has even suggested we set up a special new category for these three bodies which would set them apart from both planets and minor planets. We could call it Orbit Crossers.
Hidalgo signifies a need to prove that one is just as good as one's parents were, and also just as good (or better) than one's siblings. There is a great deal of pride in this body as to where one came from, and that part of oneself that one has inherited from one's parents. It represents a strong need to defend oneself, to prove to others that one is in the right, to stand up for one's principles. Dr. Lehman even goes as far as to say that Hidalgo represents Self-Assertion. There is also an urge to take risks, perhaps because there is the feeling that if one loses one does not lose much.
In fact, Hidalgo can lead one to act, knowing full well that one is defying possible consequences. An afflicted Hidalgo usually has much resentment, stemming from whatever house it occupies, and from what is ruled by the afflicted planet.
The above article talked much about Hidalgo's strange orbit, giving it a stay in Gemini so briefly (usually only around 1-1/2 months), that less than 1% of the earth's population has that position. Since that article, we have noted that Hidalgo in Gemini gives greater impatience than the average person, especially when trying to accomplish something, a strong feeling of being much different than others, and a powerful need to communicate all the time. As Hidalgo transits through the signs approaching Gemini, events in the house it passes through definitely tend to speed up or become more demanding of one's attention. This culminates in a peak of activity in the house containing Gemini. Perhaps this is why natives with Gemini sun-signs are so highly nervous and active, because they feel Hidalgo's transits more strongly than other Sun signs.Check out this body in synastry. If Hidalgo in your chart contacts a planet in the chart of another, you can be sure that your own rights and your assertiveness are an issue in the relationship. The most difficult aspect for Hidalgo I have seen in synastry is in conjunction or hard aspect to another person's Neptune. Here, the Hidalgo person can not seem to assert himself well, or for very long, because the Neptune person is always disrupting his attempts, weakening his efforts, and in general dissipating his actions in this direction.
(Check out a relationship where the woman accuses the husband of not being assertive enough, and you'll often find that he can't be, due to her reaction when he tries. This is a typical Hidalgo/Neptune interaction.)
One of the most intriguing verifications of Hidalgo's influence comes from studying the interactions between brothers and sisters in large families. It seems to describe quite explicitly the interrelations and inter-strife between each member and his siblings.