Colleges and universities have gone to great lengths to combat sexual assault, oftentimes with the prodding of state mandates. Despite "yes means yes" laws and school policies on affirmative consent, students don't usually go along with these mandates in their consensual sexual encounters, according to Inside Higher Ed.

"The idea of affirmative consent has resulted in progressive advancement of college policies," said Jason Laker, a professor in San Jose State University’s department of counselor education. "But just because you make it clearer what we expect in terms of consent from a legal or policy standpoint, that doesn’t change the fact that people are limited in their ability to meet those expectations."

Laker and Erica Boas, at Santa Clara University interviewed heterosexual freshman at a university in the Bay Area. Many in their first round of interviews had trouble recalling the build-up to a sexual encounter, but were more likely to say something like, "It just happened." According to Laker this response was heard "hundreds of times in our first round of interviews."

"Part of it was them being teenagers, but it was also because of mindlessness," he said. "Human beings can get on autopilot, with one thing just leading to another, whether it’s sex or the commute to your office. With sex, there’s all these taboos and stigmas and politics and complexities around the topic, as well. It can make it difficult to recall what happened."

Once students were able to recall the process, they still didn't indicate that they had asked each other for consent. Instead, there were more non-verbal cues. For one couple, there was a setup involved where he would nuzzle her neck if he wanted to have sex and if she did too, she would turn towards him, or if not, away. To another couple, consent was the boyfriend tugging on his girlfriend's sweatpants and her removing them. The examples aren't that uncommon in real-world sexual scenarios.

"In these cases, there’s an asking and answering, but not an enthusiastic yes," Laker said. "These are often the real vocabularies of consent."

Only one of the 15 students reported asking "Would you like to have sex?" Students also said they were intoxicated, often on purpose, so that the encounter would be more comfortable.

The responses might not be considered "enthusiastic" under California's "yes means yes" law from 2014, which also requires ongoing consent throughout any sexual encounter.