Timothy,
In the IPIU forums, we are all alike - we have a desire to help people. I think, or rather, feel that those who do not have the common desire to help do not stay with us for long.
To get back to the topic, I remember a talk from Major General Hatch, USMC. The general was, at the time, the DCS-Log (Deputy Chief of Staff for Logistics) for the Marine Corps; among his duties was personnel. General Hatch mentioned that the USMC was not taking recruits who had not completed high school; a GED did not count at the time. The reason was that the Marines had more than enough potential recruits that they could be picky. The general's assertion was that a high school diploma meant that the individual had whatever it took to stay with something even if they did not like it. The diploma - the sticking it out for four years in a high school - was a credential in itself. It was not an indicator of intelligence, but of determination, which is highly prized by the USMC.
While education is always important in and of itself, lack of a formal education is not an indication of ignorance or stupidity or laziness or any other negative human quality. Some jobs need more education and training (the two are vastly different) that cannot be substituted by experience. Experience counts for a great deal in investigation. In New Jersey, it takes five years of experience to apply for a PI license.
Putting education aside, which is what I believe the original question for this thread. Attitude is very important. PI work can be dull and boring - and very eshausting if you do surveillance.
We believe that PI firms read the posts in the IPIU forums to see what people are really like. To that end, we (individually) need to project positive attitudes and maybe some 'perkiness'. Being able to write well is also important in here, just as it is in the real world. See Kanda Force's threads on writing - she give great advice.
Training will compensate for lack of aHS diploma or GED if you have the right attitude.