The typical Niceguy can often be described in one word - nondescript. This is a primal genetic trait which formed from a desire to be left alone or unrecognized unless social interaction was desired. Niceguys do not like to be annoyed, and will do everything within their power to avoid annoying things and/or people. Thus, Niceguys often become disillusioned in large crowds, and have been known to suffer severe mental stress when confronted with long lines of check writing idiots at the grocery store checkout counter. This non-tolerance is often misidentified by people as aloofness, or vanity, which is of course incorrect.
Niceguys generally have a good sense of humor. They enjoy telling and hearing a good joke.
Niceguys usually share characteristics with the average serial killer (i.e. they are quiet, do well in school, and keep to themselves). This coincidental parallel should not be misconstrued as criminal tendency.
Niceguys do nice things. While this may seem obvious, there is a little known genetic flaw in the female species, which has created a non-responsive ring of rods and cones around the optic nerve which prevents the brain from processing these nice acts and connecting them to the Niceguy. This Niceguy Blindspot as it is sometimes called, was nearly responsible for the extinction of the Niceguy species until females began using their peripheral vision to recognize Niceguys.
Niceguys often seem dense or oblivious to those around them. They often miss subtle body language, or vocal cues. When interacting with a Niceguy it is imperative that you make your intentions known in a clear and concise manner.
Niceguys prefer to be au natural. In other words, they usually do not wear cologne, flashy jewelry, expensive clothing, and they most definitely would never use that fake orange tanning lotion.
Niceguys are often easily distracted by broken things. Much like moths drawn to a flame, Niceguys are repair addicts. Whether a refrigerator, a flat tire, a broken heart, or a plugged up garbage disposal, a Niceguy will leap to the rescue. This desire to help can often cause problems when the Niceguy is not an expert in a given field. For example, a Niceguy would most likely attempt open-heart surgery, if he felt that there was no one more qualified than he, even though he may be an accountant.
Niceguys have a deep distrust of anyone selling anything. A Niceguy would feel cheated if he were sold a $1 lottery ticket for $1.50 even though it's worth $10,000,000. This irrational distrust of salespeople is a phenomenon which has yet to be explained by modern science. There are several theories on the topic, but since they are all very speculative, they will not be presented here.
While this list of characteristics is a good baseline for Niceguy behavior, it should in no way be considered a complete Niceguy profile. Each Niceguy is unique, and while many traits are held in common, a true analysis cannot be made based on printed data alone. The 'science' or Niceguy identification is often an art. Use of the above data as a shopping list for a Niceguy can lead to disastrous results. A JerkGuy will often mimic these characteristics in a desperate attempt to propagate his species, which inevitably leads to trouble.
If you are interested in identifying Niceguys for scientific purposes, there are several subtle clues that can tip you off to the true identity of a seemingly ordinary male specimen: