Allegations that members of the Sayreville High School football team subjected freshman players to anal penetration bear an eerie resemblance to dozens of cases around the country.

In Colorado, the hazing case involved a pencil. In Los Angeles, a broken flag pole. In Iowa, a jump-rope handle. In Missouri, a water bottle. In Vermont, pool cues.

In New York City, coaches were fired after accusations that three members of the track team assaulted younger teammates, with one reportedly saying, "You need a good fingering, you freshman.”

"More and more we're seeing this among male high-school athletes, where this is their mode of hazing: some kind of sexual assault that involves anal penetration," said Mary Madden, former co-director of National Collaborative for Hazing Research and Prevention at the University of Maine, Orono.

"We don't know if it's getting more severe, or whether it's just getting discovered more often," she said. A review by Bloomberg News counted over a dozen incidents of high school boys being sodomized with foreign objects by their teammates in 2013 alone.

In Iowa, high school wrestlers punished younger teammates for missing practice or failing to make their weight class by rectal penetration using the handle of a jump rope.

An Illinois soccer player alleged younger members of the team were pinned to the ground, their testicles grabbed, then sodomized with a finger. The Colorado case involved the team manager, who was sodomized with a pencil on the team bus after having been bound with duct tape.

"You do unto others what was done to you. So with each season, each perpetrator wants to add his or her mark," said Susan Lipkins, a psychologist who has written, a hazing prevention guide. "It becomes a little more sexual, a little more violent."

Both experts agreed hazing “traditions” typically get worse because of the one-upsmanship each grade brings to it.

In the cycle, where the freshman victim eventually becomes the senior perpetrator, the perpetrator’s motives are likely more complicated than simply seeking domination, Lipkins said.

Someone humiliated as a freshman hazing victim would’ve had to stifle his feelings of seething anger and helplessness for years, she said. In cases of sexual assault, the victim can feel as if he’s lost of piece of his identity.

“From a psychological point of view, when someone’s hazed, he loses a sense of himself, especially if it’s of a sexual nature,” she said.

Being “promoted” to the role of perpetrator can then be emotionally restorative, in a curious way. “He’s getting back that piece of himself that he lost,” she said, by now being the person in control of the hazing. He may then feel he can finally put his lingering sense of victimhood behind him.

There is no difference psychologically between the use of a finger or an object in the hazing penetration, Lipkins said.

“Rape is rape. Sodomy is sodomy,” she said. “I have a theory: The quickest way to humiliate a macho guy is to turn the victim into a “girl” by penetrating them. It’s an instant demasculization. It’s the quickest way to take away any power and make the victim the lowest man on the totem pole.”

Some episodes of more mild hazing have put law enforcement in the position of having to conclude no charges can be filed because no law has been broken, said Madden.

That’s hardly the case with anal penetration, however. It doesn’t matter if a state has specific laws against hazing, she said, because the act itself falls under criminal statutes.

Kathleen O'Brien may be reached at kobrien@njadvancemedia.com, or at (732) 902-4557. Follow her on Twitter @OBrienLedger. Find NJ.com on Facebook.