Sales of Kleenex will probably take a dip now that This Is Us will be off the air for a few months after its Season 2 finale. Where will viewers turn to get their weekly cry fix now?

NBC's Rise - which will take over This Is Us' time slot (Tuesdays, 9/8c) starting next week - is a likely contender, given that it comes from Jason Katims, the man behind beloved sobfest Parenthood and Friday Night Lights, which produced its share of sniff-inducing moments. But perhaps the bigger question is, why do people flock to shows that turn them into blubbering messes on their couch week in and week out? The reasons are more complicated than you might think.

One answer might seem fairly obvious: Viewers are drawn to television shows that make us emotionally invested in the characters, and most of the time we derive pleasure from that emotional investment. But especially on heavy dramas, things aren't always hunky dory for the characters, and viewers' emotional investment works both ways.

"In order to successfully be a tearjerker, a show has to be successful in making you care about the characters," says Dr. Jennifer Barnes, an assistant professor of psychology and professional writing at the University of Oklahoma who has researched the connections viewers feel with fictional characters. "We suffer when they suffer, but we also get great joy when they find joy. These shows, if they only delivered sadness all the time probably would not be as successful as they are. They're delivering a mix of emotions. And part of their ability to make us so sad is that they can also make us so happy."

Turns out writer and producer, Katims has been subconsciously working toward this balance the whole time: His goal isn't to make the audience weep every week, but to deepen the connections that they feel for those characters. And if that results in the occasional tear being shed, then so be it.

"Is it that people enjoy actually being moved to tears, or do they enjoy actually seeing a story that makes them feel and seeing characters that they feel like they could connect to?" Katims wonders. "That's what makes you emotional, I think, when you watch something, is you feel like you personally connect to it. That feels like the kind of stories I gravitate to, both as a viewer and a storyteller...Shows that sort of tap into your emotional life, there's something just naturally appealing to [them]. To me, it means that you feel connected to the experience and you're not watching it from a distance."

But isn't it kind of weird to feel such deep connections to people who aren't even real? Not really, according to Barnes. There's a psychological term for the connections we form with fictional characters and celebrities: parasocial relationships, meaning relationships that are in essence imaginary because they only go in one direction.

"You might feel like you know the Big Three on This Is Us really, really well, but they don't actually know you at all because they're fictional and they can't know you," Barnes explains. "Especially if you're watching the show week after week, these are people who can be a part of your life for an extended period of time, and you might actually feel like they're friends. So of course you're sad when something horrible happens to one of them - or, heaven forbid one of them dies and you lose a friend."

In fact, frequently, it can feel like we know fictional characters better than we do the people in real-world lives. This is mostly intentional on the part of writers, and the choices they make about what to show the audience about the characters they create.

"Part of the point of fiction is, it gives you this insight into other people's lives that you would never get in reality. In fiction, you get to see who people are when they turn away from everyone else in their world," Barnes notes. "Oftentimes, [a character] will have this hidden vulnerability, or they'll have a secret, or they'll not want other people to see them cry, for instance. No one in their world knows these secrets or gets to see them cry or gets to see them without any of their armor or masks on - but we as the viewers do, because we as the viewers are there with them when they are crying in the shower, or when they turn away from everyone else and we see something on their face that they didn't let anyone else see. Fiction is oftentimes built for us to get into the minds of other people, and then you grow to know them so well. Arguably, we know them... better than anyone except for our very closest friends in the real world."

Some studies have even shown that participants reported feeling more grief over a fictional character's death than the (hypothetical) death of a real-world acquaintance.

Merely the unconscious act of forming these parasocial relationships, regardless of the impacts they have on our emotional states, has psychological benefits for people. Research shows that having fictional "friends" can actually boost self-esteem in individuals who aren't getting what they need from real relationships. In another study, people also demonstrated better cognitive performance in a room where photos of their favorite celebrities and fictional characters were hung.

Our ability to form these connections in the first place is rooted in a philosophical concept known as alief. First proposed by Tamar Gendler, a professor of cognitive science and philosophy at Yale, the notion suggests that "aliefs" are a psychological phenomenon by which a person holds attitudes or feelings that often go against what they intellectually know to be true.

Barnes ties the idea to our reactions to fictional events thusly: "You might believe fictional characters are fictional, but you can alieve and kind of feel like they're real. If someone asked you, 'Is that person real?' You would say, 'No, I know they're not real. ... But I totally feel like they are.' And so, it could be that because of this alief, gut-level impulse we have that fictional characters are real - even though we know they're not - that our closeness is driving this [attachment]."

On an even deeper level, the pleasure derived from crying at a TV show is also related to humans' meta-emotions, or feelings about our feelings. Our feelings towards fictional characters are oftentimes much less complicated than our feelings towards people in our actual lives, in part because the direct impact fictional developments have on us is minimal.

"In the real world... sometimes you feel sad about feeling sad, or guilty about feeling sad. For example, you feel sad when your best friend gets engaged, and you feel guilty that you feel sad because you should be happy for that person," Barnes explains. "But, in fiction... we might actually appreciate that we're sad, because feeling it in this fictional context might make us sort of appreciate this full spectrum of human emotion that we're capable of. Even though we feel a very real sadness in response to tragedy, it's not a sadness that's going to have a lot of consequences for our real-world lives. In some ways, we're getting to feel this full spectrum of human emotion without having to actually bear the weight of the real-world tragedy that would normally accompany sitting around and sobbing. ... You can go about your day-to-day life without your life having changed in the way that a real-world tragedy would have changed it."

With This Is Us in particular, Barnes believes there's another element of human psychology behind the show's popularity - and it's one that doesn't involve getting a somewhat masochistic thrill out of weeping, but rather a sense of belonging. The same can be said for Rise, whose ratings are thus far untested, since it just premiered last week (and with a This Is Us lead-in to boot). Rise isn't a tearjerker on the same level as This Is Us, but as with other family dramas (and Katmis shows), it offers viewers a glimpse into a somewhat insular group(s) — in this case, the drama department of a high school in a struggling small town, not to mention the families of many of the main characters.

"Humans have this universal need called the need to belong. We need connections with other people, but we also need to feel like we belong in some kind of group," Barnes says. "If you look at the title of This Is Us, there's an 'Us.' There's a group there to belong to. In this case, it's a family. I think the show does a really good job at inviting viewers in to being a part of this family, in part because you get to see their background. You get to see how these people became who they are today. You're with them for multiple generations, and there is this closeness that the different family members share. ... Although people are very attracted to This Is Us because it is such a tearjerker, I also think a large part of the pleasure is, they just get to be a part of that family and see those people overcome challenges and see them grow and rise and fall."