Fred's level of intelligence differs depending on the series that he's in. In the Original series he has above-average intelligence and often contributes useful information to help solve the Mystery, while in the Pup Named Scooby Doo series he was shown to be rather below average, offering useless information and often accusing the first person they suspected as the culprit.
Fred has been shown to have a love interest in his fellow group member, Daphne Blake. This is commonly seen throughout his choice to split up the group, sending Shaggy and Scooby off in one direction ( sometimes sending Velma with them ) while he pairs himself with Daphene. Their relationship has never been concrete during any part of the groups history, though there remains heavy speculation among the fans.
In Scooby-Doo! Mystery Incorporated!, Fred Jones is the illegitimate son of Mayor Frederick Jones Sr. He is also the leader of a group known as Mystery Incorporated, a group of teenage detectives and their dog named Scooby Doo. Fred is also a skilled trapper, often creating complex Rube Goldberg contraptions out of every day items to catch crooks and trouble makers. More often than not these traps are sprung by Shaggy and Scooby Doo, the groups goofballs.
Fred is a Caucasian male with Blond hair and and Athletic Build. In the original series, it is implied that he is touring around the country during the summer break between high school and college, although this is later forgotten. The original plan was that he was heading for Woodstock, but that idea never made it into the actual series.
Fred traditionally wears a collared blue dress shirt underneath a white sweater, orange ascot, blue jeans, and brown shoes. Fred has gone through several changes throughout his history, though his color scheme of blue & white stays the same. Essentially Fred fills the role of the "preppie" in the group along with Daphne.
Fred is an athletic male who displays leadership abilities and considerable charm. He's been the leader of Mystery Incorporated since its creation. Fred also has a decent display of driving skill, being the driver of the Mystery Machine during all of the groups travels and adventures, and he has also shown the ability to drive boats. Fred is also skilled engineer who can create effective traps out of nearly anything.
Fred shows high levels of strength, being able to tear off the head of a zombie during the Night on Zombie Island film. Along with his strength levels he seems to have increased levels of speed and stamina, constantly able to run for extended periods of time at above average speeds, probably because he has so much experience running for his life on his many adventures.