"If it weren't for his cock, he'd be a hobo riding the trains around the country," Steve says. "It's opened doors for him. Rich women put him up at their apartments. We have friends who have more money than him and are more successful than him, but they all say, 'I want to come back as this guy.' Secretly, we all want to be him."

Does it really come down to this? Millions of years of evolution culminating in a highly advanced society whose members are adept at evaluating worth on the basis of intelligence, compassion, creativity—or even money—and it turns out our core psychology is still governed by the length of our reproductive organs?

"Are you kidding me?" says Josh (who's 33 now and has started over as a physical therapist). "That's basically my philosophy on life! Whenever it gets bad, I'm like, 'Hey, I got the one good thing!' My ex-girlfriend called it BDS—Big Dick Syndrome. It was hard to even have an argument, because I'd just be like, 'Whatever.' It's an ego thing. Because when it comes down to men, I mean, really, what else is there?"

This is obviously not a popular notion among sex therapists, who tend to be of the opinion that "it's what you do with it that counts." But such reassurances are all but inaudible amid the phallocentric babble that permeates our post—Sex and the City dating landscape.

"Size matters only if you let it matter," says psychologist and advice columnist Dr. Joyce Brothers. The thing is, a lot of us are letting it matter—and not just within the confines of the bedroom but as the unspoken arbiter of our confidence. It turns out we've been doing this for a very long time. According to a 2006 report by the British Journal of Urology International, there is evidence that "prehistoric cave dwellers attributed the symbolic values of strength and power to penile size, as well as those of virility and fertility." And some anthropological-minded observers confirm what none of us likely want to hear—that Josh isn't lost in some fun-house mirror-land of his own personal delusion. He's enjoying the satisfaction that comes from living in a world that has made him its king.

"It's part and parcel of the whole thing about male size and power," says Dr. David D. Gilmore, cultural anthropologist and author of Manhood in the Making: Cultural Concepts of Masculinity. "I mean, look— the big man is attractive to other men and to women. He's admired. Big, strong men stand out, and the penis is a symbol of bigness, of strength, of mastery." In ancient Greece, Gilmore says, a big penis was actually considered vulgar—irrelevant, even detrimental, to the proportional athletic ideal. But it's not uncommon for Mediterranean mothers to kiss their babies' penises and say, "Grow, grow, grow!" And if size weren't the very fulcrum of even the most sophisticated and accomplished male egos, why would F. Scott Fitzgerald ask Hemingway to take a look at his apparently not-so-great Gatsby in the bathroom of the Brasserie l'Escorailles? For that matter, how did a guy like Milton Berle score with Marilyn Monroe?

The answer is unsettling. The title, the diploma, the Raymond Weil. The Danish lingerie model. What are these compared with the ultimate eugenic advantage? Penis size is the final word—the argument ender, the longest straw.

Figures vary, but the generally accepted average length for an erect penis is somewhere between 5 and 5.9 inches. A 2002 study conducted by the International Journal of Impotence Research found that most men seeking penile-lengthening procedures actually have normal-size penises. And, according to the British Journal of Urology International report, while 85 percent of women polled said they were just fine with their partner's size, only 55 percent of the men were satisfied with their own measurements.

Trying to draw a quantifiable link between penis size and the male psyche is a complicated endeavor, which is why scientific research is scant. But Trojan, manufacturer of Magnum-brand condoms, has been filling in the gaps—conducting studies to determine the psychology of its ostensibly more gifted clientele. "They claim to be very spontaneous and very assertive," says Trojan's vice president of marketing, Jim Daniels.

But Daniels divulges a potentially devastating secret: The Magnum isn't any larger than Trojan's other condoms. Its comfortable fit is due to an innovative "baseball bat" shape. The length and circumference are identical to those of other lines. Only the XL variety is larger—by 30 percent—and that's only required by about 6 percent of the male population. "You've got the image of the package—it's premium; it's gold foil," Daniels says. "And what guy doesn't want to think that he can handle a Magnum condom? There's a certain machismo involved."

Sound familiar? It should. Because human behavior will always be subject to the same social dynamics that played out at elementary-school—and penis size is no exception. Short men have Napoleon complexes. Coworkers still ridicule each other about their shirts. And successful young businessmen aren't above shoving it in your face—sometimes literally. Take G.C., for instance, a 31-year-old New Yorker who works in finance who taunted his pals one night after a few too many drinks by pressing his 8 1/4-inch member against the window outside a house party in the Hamptons—and knocking on the glass to get the partygoers' attention.

"Everybody got a kick out of it," he says. "There were guys and girls around. They were just like, 'Dude, put the fucking hammer away.'" Apart from occasional drunken exhibitionism, G.C. says he makes it a rule never to mention his good fortune in conversation. But he also suspects it's spurred him to act in ways that the less gifted might not contemplate—like the time a girl brought him home only to find out she didn't have large enough condoms. When G.C. went out to get some, he stopped off for a cheeseburger before he got back to business (and no, he didn't get one for her).

"Nothing really bothers me," G.C. says, "because everything kind of comes back to that. No matter what happens, I got a major fucking plus in my pants—know what I mean? It's the one constant factor."

In the far-right margin of the size curve, though—where only animelike proportions reside—being well endowed can be much more than a mere "constant factor." It can be an all-out magical power. Jonah Falcon, 37, a cable-television host in New York who's gained worldwide recognition for his 13 1/2-inch length, attributes losing his virginity at the age of 10 (with a woman eight years his senior) to nothing more complicated than his size. He has also observed something far more miraculous: So great is man's obsession with size, such are the power and mysticism radiated by a superlative specimen, that some are willing to compromise their sexuality just to get close to it.

"I've seen straight guys that turn gay around me," says Falcon, who is bisexual.

Falcon offers this reassurance to the 99.999999 percent of men who may be intimidated by his terrestrial presence: This gift has not been a panacea. Some insecurities don't just disappear with the wave of a magical 13 1/2-inch wand. His bounty has not, for instance, made Falcon feel any better about his weight. "I'm endomorphic, so I have to work out all the time," he says. "I can't always take off my pants, you know. Sometimes I just want to feel good about taking off my shirt." It's nice to know there's still some truth to the one about life's not being fair.

If it were fair, you would be getting more ass than Ron Jeremy.