In the high-tech field startups routinely try to hire technical staff who aren't married and have no kids, because these people tend to have lives where they don't mind staying at work for much longer periods of time.

I've never heard of anybody whose been married being discriminated against as such. I think theres more discrimnation for couples or even single parents to be discrimnated against for having children. Some companies get funny when they have to fork out for childcare or for parents who take time off work if their kids are ill.

I will add a second whiskey tango foxtrot to this idea.

Usually more for men than women, in my experience, although I've heard it the other way round. I don't think this is the factor it used to be.