In the study, published online recently in the journal Appetite, 466 Belgian students answered surveys about their childhood eating patterns and their current social behaviors. Results showed that students were significantly more likely to report current altruistic behaviors if they'd eaten home-cooked meals growing up. These actions included holding open an elevator door for someone, giving a stranger directions, giving money and goods to charity, offering up a seat on public transportation, and helping someone move.
The study's authors suggest this is because those family dinners instilled an idea of fairness in the participants' childhoods, creating an environment in which giving to others was the norm. Although that might seem like a stretch, other studies have found similarly heartwarming effects of sharing meals (even among U.S. college students).
But, as Time notes, the point here is sharing the food, not just the company. And, the study looked at how actions in childhood (up to age 18) influenced behavior in young adulthood. Because the students' average age was 20, this "adulthood" spanned about two years and can only be seen as a correlation. Even if there is a causal relationship, it might be a while before there are any noticeable changes in your roommates' behavior after you cook them an amazing, family-style dinner. Still, it's worth a try — and could be especially useful when it comes time to move out.