DENVER - If professor Robert Cialdini is right, the University of Colorado campus will be flooded with more students wearing black and gold than usual on Monday, following the Buffs' 24-3 victory over Colorado State University during Saturday's Rocky Mountain Showdown.
Cialdini, a professor of psychology at Arizona State University, conducted research at seven major universities that concluded college students are "significantly more likely" to wear school-themed apparel following their school's victory in a weekend football game.
"The larger the victory, the more they did this," Cialdini said. "It wasn't the hard-fought, close games - it was the clear stomping of the opponent that made people want to be identified with the team."
To the thousands of CU fans who packed into Denver's Invesco Field on Saturday, the victory over the rival Rams certainly qualified as a stomping.
"I love to see CU win before my last year" at CU, said senior Brian Barenberg.
Barenberg said the game was "sweet vindication" for the Buffs' loss on their home turf during last year's showdown, when CSU fans danced on Folsom Field.
The Denver stadium served as neutral ground for this year's game, largely separating CU and CSU fans at opposite corners of the field.
Still, the fans traded verbal jabs from afar. When one side broke into its school fight song, the other was sure to follow. Other taunts included profanity-laced chants and the occasional vuvuzela - the deafening plastic trumpets that became famous at this year's World Cup.
The CU student section - which included students wearing face paint, body art, outlandish wigs and an ocean of gold shirts - exploded into high gear following the Buffs first touchdown in the first quarter.
"It means everything," Blake Dickenson, an 18-year-old CU freshman, said of the 18-yard score. "It sets the stage for the game."
On the CSU side, freshman Keegan Deignan said he was enjoying the atmosphere of his first football game as a college student.
"It's noisy, it's rowdy and it's awesome," he said. "We're way more rowdy then they are."
But as the game went on, and the Buffs score increased to a 17-0 lead at halftime, the CSU fans became noticeably more quiet.
By the end of the game, what had been an ocean of green and gold had mostly evaporated, and the CU student section broke out into song as people filed out of the stadium.
"It's quite the environment," said Megan Rieder, a 21-year-old senior at CU. "I love it. It's so much fun."
Some students complained about the heavy security presence at the game, which included ticket checks at the front gates and several other times en route to the respective student sections.
But according to Denver police, the crowd was well behaved. Most of the problems stemmed from alcohol, officials said.
Police arrested 80 people - all for alcohol-related charges, said Lt. Matt Murray. An additional 11 people were ticketed for alcohol-related reasons and released, he said.
One person was arrested on suspicion of driving under the influence of alcohol.
Police took 44 people to an alcohol detox center, and 21 people were ejected from the stadium, Murray said.
There were no reports of fights at the game, he said.
"There were no significant law-enforcement issues," Murray said. "We consider this a successful event. When you get (60,000) people, especially in a college rivalry game, this is pretty good."
Malinda Miller-Huey, a spokeswoman for CU, said the early start time of the game and the large, neutral venue helped reduce potential problems.
"It really looked fairly well behaved, even more well behaved than two years ago," when the game was last played at Invesco, she said.
For many fans, the fun began hours before the noon kickoff, as the parking lot at Invesco became a blur of black, gold and green.
Many fans from both schools converged outside the NFL stadium before 9 a.m.
Tim Wadsworth, a 34-year-old lifelong CU fan from Littleton, began grilling quesadillas and heating up salsa.
The self-described "hard-core" football fanatic was predicting a landslide victory for the Buffs, who are now 60-20-2 against the Rams.
"To me, it's not really a rivalry because they haven't beat us that many times," he said.
Elsewhere in the sea of color-clad bodies were "beer pong" tables and bean-bag toss games.
The crowd was under the watchful eye of Denver police, who roamed the grounds checking IDs and issuing tickets for underage drinking.
Aside from some relatively friendly trash talking, the crowds remained calm throughout the morning.
"We look forward to it a lot," said CSU alumna Becky Rae. "It's fun to come out and watch two rival Colorado schools kick each other's" - ahem - butts.
Keith Arment, a 21-year-old CU alumnus, and Brooke Anderson, a 21-year-old CSU senior, have been dating for six months. They said Saturday was the first time their school loyalties came between them, something they chose to settle with a simple bet.
"If CU wins by 21, then she's a CU fan for life," Arment said with a grin.
One thing the couple agreed on was the choice of Invesco as a venue for the game.
"Invesco is so much better" than the school stadiums, said Anderson. "Except (last year) when we got to go to Boulder and danced on Folsom Field."
Many tailgaters agreed on the benefits of the much larger stadium.
"It's a lot better because there is more room," said CU junior Casey Craddock, who was in the process of grilling food for about 150 of his fellow CU students Saturday. "Frankly, there is less hostility too. It's easier to control when there is more room."
Besides being a rivalry game, Craddock was looking forward to Saturday's showdown to wash away last year's disappointment for the Buffs.
"This is way important," he said. "It's the season opener. It gets the season off to fresh start. It's the most important game of the year."
Camera Staff Writer Joe Rubino contributed to this report.