I like the generational epic part of DF, and generally try to nurture my dwarf families. Considering ways to preserve thin bloodlines, I looked at the relationships and marriage sections of the wiki and searched these forums but didn't find much that clarified dwarf matchmaker preference. So I decided to do a little experiment with my population. I'm curious whether what I found matches with the conventional wisdom around these parts.
I started with 102 single dwarfs. I assigned 70 of them in equal numbers of male/female to restricted socialization burrows, while the other 32 were left free to take care of daily fortress business with the already involved/married/widowed members of the population.
My "open" burrow covered the center of my dining hall and portions of my food/drink stockpiles. Participants here were free to mingle with the rest of the population as they passed through, and to travel off-burrow for something if they were so moved.
The other burrows covered 5X5 rooms with engraved walls, furnished with a table and chair (designated dining room), food and drink stockpiles, a bed, and a few statues. When the designated population of that burrow had gathered in it, I locked the door and designated a statue garden covering the room to bolster happy thoughts.
I kept them burrowed for one year, checking in regularly on the relationships screens of the participants. At the end of this time, all dwarfs in each burrow were mutual friends and nearly all had developed lovers or married. At the start of the next year, I had 28 single dwarfs. Many participants in the "open" burrow became involved with general population members who came to idle in the dining hall. (Open burrow members also formed several general population friendships, especially with children, as I expected.)
In my population, the absolute limiting factor was relative age. No dwarfs formed romantic relationships with anyone more than 10 years older or younger than they were. With suitable age matches, and plenty of time for repeat socialization, they paired off.
Of those who formed relationships, dwarves from the same "professional caste" (as defined by color) paired off more often. By this I mean "grey" metalsmiths, "blue" craftsdwarfs, "brown" agriculturists etc. Although I did have three "yellow" carpenter/bowyer<->"blue" woodcrafter pairs that my mind wants to connect as "wood-based professions," I expect that was coincidence. The in-caste relationships were just more frequent though; plenty of mixed-profession relationships formed.
As I expected, dwarfs with highly social personality traits made friends with their burrow companions faster than others, and generally entered romantic liaisons faster. Outside of paying attention to that trend, I didn't try to track whether specific personality traits were more often to lead to lover relationships, but in general dwarfs got involved and married with others with disparate personalities.
The progression from lover to married happened at wildly different and to me unpredictable intervals after the relationships formed. While I've had dwarfs be lovers for years in normal fortress life, the enforced repeat-socialization environment effectively accelerated this. Most of my former dwarf bachelor(ette)s were married at the end of the test period.
I had one couple who were both fairly antisocial and self-conscious who had formed friendships with everyone else in their burrow, but were only long-term acquaintances to each other. One was an armorer, the other a glassmaker. On a whim I activated armoring/glassmaking on both, and they married before I got around to checking their burrow members' relationships again. I think this was coincidence.
By contrast, I had one pair assigned to a burrow containing only each other. Both were highly social, making friends quickly, enjoying the company of others, admire tradition, great sense for social relationships (and music). They worshiped the same gods. They were both clothiers who also did weaving, dyeing, and spinning as side jobs (and were proficient planters, although this was not enabled). They were separated by 12 years of age. They became friends almost immediately, but never partnered.
A few dwarfs not in the experiment also became lovers. My favorite of these was a pairing between a speardwarf and my chief medical dwarf. The speardwarf went down to the caverns to retrieve a xcloakx and had a run-in with a jabberer. He put it down readily enough, but incurred a severe beard injury (broken tissue, heavy damage, infection). After the incident, he went to the hospital to Rest Injury. The CMD diagnosed him, washed his beard with Giant Cave Spider soap (for the silkiness?), sutured his beard with forgotten beast hair thread. They were passing acquaintances when he went to the hospital, and got married as soon as he got out of bed, throwing a wedding reception at the well in the center of the hospital. In the midst of my locking dwarves up to get them to "date," I found that a wonderful spontaneous event from the RNG and a fitting dwarf romance. They were the only man and woman in their 90s in the fort. (Poor Vabok's beard enjoyed a partial recovery, and cleared the infection. I imagine the mangled hairs are rather sporting with the FB hair suture/braid/graft/whatever-it-is.)
At the end of it all, the 28 single dwarfs include some with no eligible mates in the population. I've got two women, aged 34 and 48, and several men (2 in their 70s, 1 in his 80s, 1 in his 100s and 1 in his 110s). The other unattached dwarfs are young up-and-comers in their teens, although 2/3 are women. I stuck two of the teens with different professions and different personality traits, who were not yet friends, in a burrow by themselves after the experiment year, and they became lovers within a month.
TL;DR - from what I found in my fort, two dwarfs of different sex within 10 years of age to each other, given circumstances that foster repeated socialization, are likely to become lovers. More social dwarfs, and those of similar professions, seem to pair off more quickly, but only age and social exposure seemed to limit relationship formation.
Does this match others' experiences?