I'm suggesting that people are impressed by large ones - on a subconscious level - thinking that the longer the cock, the deeper it will penetrate, the closer it will be to the egg when the man spews his load. My key words there: It was thought.
Of course, we know by science that size doesn't matter at all in procreation.
"In school mine was the smallest penis in the gym class shower. At 19 and living away from home for the first time my eyes were opened. My roommate was working the graveyard shift and his cousin was staying for a few days. One thing led to another and we had a great time together. The cousin had this beautiful big cock hanging between his legs and of course I was envious of it. The surprise for me came when he comes up with "How do you get all that in your shorts?" My erection was longer and thicker than his was. Later, through the years, I've had this happen several times at chance secret meetings. Now at this later stage of my life, my husband who has been out his entire life tells me he has only once encountered a cock larger than mine."
Many studies over the past 20 years (my gosh! how time flies!), have found there are two types of cock when it comes to size: The Showers - those that are impressive when soft, yet don't increase much in size at all when hard. The Growers - those that are small when flaccid, and expand to above average dimensions when fully erect.
The thing is, we obsess over the size of our cocks. We compare ours to others we see. We look at the other dudes in the locker rooms and showers at the gym.
We'll look at other guys when they're taking a piss out in the open
Or when we're in a big group
We'll even try to take a peek at guys taking a leak in men's rooms.
All you straight dudes out there - it's okay, you can admit it! We all look when we've got the opportunity to check out the competition. It's normal psychological behavior. Honest.
What's the actual psychology of it? For the long and short of it (lol) I'll have to do some more research.
But we do look, we do compare, we do care. For some reason, size matters.