Why we let users exclude potential matches

For a long time, the convention in matchmaking software has been to ask only what you want, never what you do not want. The positive form is more polite, the thinking goes, and the negative form invites bigotry. So you’ll see “preferences” instead of “requirements,” “ideal match” instead of “deal-breakers,” and a universe of euphemism around the very real fact that adults choosing a life partner have boundaries.

We disagree with this convention. Strongly enough to do something about it.

Five categories where excludes are the right primitive

PotentialSpouse lets you express excludes in five categories where the negative form is genuinely more honest than the positive one:

1. Genetic markers — most importantly the haemoglobin markers (AA, AS, SS, AC, SC). If you are AS, the medically relevant question is not “what genotype do you prefer in a partner” — it is “I cannot marry someone who is also AS or SS, because our children have a one-in-four chance of sickle cell.” That is an exclude, not a preference.

2. Decision authority — for instance, “head-of-household husband.” If a man’s marriage model is unilateral decision authority, and yours is collaborative, this is incompatible. Asking “do you want collaborative decision-making” is not enough; he might also want collaborative decisions and still expect to be the tiebreaker. The exclude form removes the ambiguity.

3. Gender role expectation — “submissive wife,” “stay-home dad.” Same shape of problem. Two people can both want a loving marriage and still have incompatible role expectations.

4. Relationship style — monogamy versus polyamory. Excluding polyamorous matches when you are strictly monogamous is not a judgment; it is a useful filter for both sides. The polyamorous user does not want to spend an hour in a chat that ends in incompatibility either.

5. Work pattern — “no night shift,” “no extensive travel.” If your life requires evenings together, that is a real constraint, and “looking for a partner who is home in the evenings” misses the case where the candidate’s profile says they are home but their tags include night shift work.

Notice what these have in common: in each case, the matching question is medical, structural, or schedule-bound, not aesthetic. None of them are “I do not want to date short people.” We do not provide an exclude for height, body type, age, or income, on purpose.

How the exclude actually works

The matching SQL applies excludes in both directions. Your exclude list filters out candidates whose my_* tags include anything you have flagged. And any candidate’s exclude list filters out you, if your my_* tags include anything they have flagged. This is symmetric, and it has to be. A matchmaker that let one party silently sneak past the other party’s exclude would be doing the wrong thing.

The matching engine treats excludes as a WHERE clause:

Show me candidates where my excludes do not intersect with their attributes, AND their excludes do not intersect with mine.

This is the same chain that runs on every wall load and on every profile mutation. The cost is a single additional array overlap per excludable category — about three microseconds at the scale we expect to operate at for the next several years.

The thing this is not

PotentialSpouse is not a tool for prejudice. We deliberately did not add an exclude for race, religion, or nationality. There are people who would want those, and they are welcome to use a different product. Our take is that someone who needs to filter on those dimensions before reading a single sentence about a human being is not the user we are building for.

The five exclude categories above are different. They are constraints that two well-meaning, generous people can have, and that no amount of conversation will dissolve. The most respectful thing the platform can do is surface them early, name them honestly, and route both parties past each other instead of into a relationship that ends in heartbreak.

A small story

A friend who tested an early build of this told me, “I am AS. I know I am AS. Every man I have dated for the last four years has been AS. I never thought to ask, because I never thought it was my place to lead with that.”

The exclude form gave her the language to lead with it. The next person she dated was AA. They are getting married this autumn.

That is the case for negative preferences.