CP Snow said that there are two cultures which divide Western culture: science versus humanities. While the division in Snow's book was between those who see science as objective versus culturally embedded, often people speak of the norms associated with the cultures: the scientific culture values pragmatism and objectivity, while the humanistic culture is more idealistic and romantic so doesn't privilege pragmatism above ideals. In what I am sure is an oversimplification and misapplication of precise philosophical terms: scientific culture is utilitarian and consequentialist; humanistic culture is deontological. The two cultures may differ in their use of language (even setting jargon aside) and decision-making process. All dichotomies are false, but some are useful, and I'll explore this one.
As some readers have noticed, I am definitely on the scientific side. (Of course, the trend towards interdisciplinary and quantitative work has suffused the academy, so there are now scientific folk even in the humanities, so this doesn't imply anything about my field.) Conversation has a certain ratio of sociability to information, and sometimes you just have to set aside the information and be happy to be talking. People who value conversation primarily for information exchange will email their conversation partner afterwards (sometimes even if they didn't like them!) if they find out a new fact; people who value conversation primarily as sociability wouldn't see the need unless they wanted an excuse to talk with the person afterwards. Valuing conversation as information exchange may not be intrinsically characteristic of the scientific culture, but the stress on information and facts does go along with it. Until 2 years ago, I thought conversation was primarily about information exchange. That sounds really funny, like I'm autistic; I'm actually pretty sociable, at least among geeks.
Humanists can value what they don't understand, while scientists want to know why something is useful before they value it.
From the outside, it can look pretty weird. My roommate and her boyfriend both attended a tech school, though one of them is no longer in a scientific field. They spend hours upon hours in intimate conversations on topics such as how thermostats work or their offices' computer systems, all while gazing lovingly into the other's eyes. They discuss people sometimes and they play with mutual friends' children together, but quite a lot of the time, they discuss these factual, concrete topics as if they were the most romantic in the world.
I've dated across the two cultures, and I know of many successful marriages across the cultures, but I think there is additional comfort with someone from the same side, and it's not about shared interest.
Lately I've been seeing a sociable science-type in a canonically geeky field. After the passive-aggressive guy who was a canonical humanist, it's such a relief to be with someone from the same side of the cultural gap. Many of the other people where I think there's serious potential are also on the same side of the cultural gap. I say that the reason for the comfort is culture rather than shared interest because --- unlike with my roommate --- science or math rarely comes up. I don't go to science museums, program computers, or talk about calculus in my spare time; it's kind of nice to be with someone where I suppose we could do these things, but it almost never happens. There's simply comfort in the shared culture; despite being what a commenter called overly-analytical, I can't even start to be more specific about why.