No, they don't do that either. To mention one data point, there's a founder in the current batch who has three small children and is a solo founder. I don't think YC cares about that sort of thing, other than that the group partners (the people who work most closely with founders) would do what they could to support them if they were getting overwhelmed.
When YC rejects an application it's because they don't think that startup (or that product/founder combination, let's say) is likely to become a big business. That's the theory, at least. Of course it's not going to be perfect in practice, but YC's success depends on getting it right, so there's a strong incentive not to just naively repeat the known, large-scale biases people tend to talk about (you mention age and marital status, one can add race, gender, class, education, national origin, and others).
Also, YC is pretty diligent about studying its failures—companies that applied to YC, were rejected, and went on to become successful—and if there were any obvious patterns in there, you can bet they'd be all over it. I'm not claiming that's sufficient to disprove bias but it must count for something.
When YC rejects an application it's because they don't think that startup (or that product/founder combination, let's say) is likely to become a big business. That's the theory, at least. Of course it's not going to be perfect in practice, but YC's success depends on getting it right, so there's a strong incentive not to just naively repeat the known, large-scale biases people tend to talk about (you mention age and marital status, one can add race, gender, class, education, national origin, and others).
Also, YC is pretty diligent about studying its failures—companies that applied to YC, were rejected, and went on to become successful—and if there were any obvious patterns in there, you can bet they'd be all over it. I'm not claiming that's sufficient to disprove bias but it must count for something.