I have to agree with Doe on this one, they more than anything want to be acknowledge, at least in my contact with them and once you have done that they tend to move on and do their own thing.

Here are the 3 types of Shadow people.  

Types

Category 1
This category falls into drugs use, seizures, and other mental issues. This category covers a very vast description and is known to have descriptions that may or may not match what others describe in category 2 and 3. Category 1 actually may not be considered shadow people at all due to the non consistancy in the descriptions.


Category 2
This category falls more into the ghost and spirit category. The descriptions in this category are as follows: non human shaped shadows or masses of human shaped shadow people in one place, insect shadows, animal shadow people, and women shadow people. These are mostly see thru shadows. Category 2 shadow people tend to be drawn more to a location than a person. It is common for this category to actually try and not become seen. Light may affect this group.


Category 3
This category does not fall into the ghost or Spirit category. This category has only 2 types of shadow people, One tall shadow man and several small hooded "twin" style shadow people. These are usually seen non see thru however they may be see thru. This category is more drawn to a person rather than a place, this category may actually be drawn to a certain spirit or ghost as well as humans. This category tends to not care about being seen. Light has no effect on this group.

Very interesting information on shadow people.  Is there a book or resource for this information to learn more?