Decades ago, the San Diego Chargers hired a psychologist to examine the "mental" makeup of the team to see if there was something management could do in that regard to get the team winning again. The psychologist (or was it a psychiatrist) made some surprising discoveries and was allowed by the team to review his findings in a film review they made.
He picked the Offensive and the Defensive Backs as comparative examples. He went into the locker room with the filming crew and showed the two groups' lockers while they were on the practice field. The offensive linemen's lockers were to a man, neat, clothing hung up and toiletries well organized on the top shelves. The shoes were paired up and centered in the bottom of their lockers. He went on to say that of all the players complaints about practice, only the offensive linemen complained that practices were too short and wanted to stay out on the field longer.
Then he took the film crew over to the defensive back's lockers. Again, to a man, the defensive backs lockers were a mess. Clothing unhung and just thrown into the lockers. The stuff on the top shelf was often just lying on its side or sometimes there was nothing there. The psychologist then pointed out that all the players had an assigned parking area but one of the defensive backs parked two blocks away, just out of spite.
He went on to point out the Offensive linemen's mindset was that of a "group" and the simultaneous movements immediately after the snap a coordinated movement, like a military maneuver or dancers in a ballet. He then pointed out that the mindset of the defensive backs was that of an assassin. Individuality, stealth, boldness and cunning.
This was a presentation I saw in the 1950's or 1960's, or possibly the 1970's. Some of the details are blurred, but I've never forgotten it's impact on me because I thought the teams all had a common mind set. Of course, I learned to play football when you always played offense and defense.
I just loved it, both running with the ball and tackling guys.