I was visiting a friend this weekend and he was showing me his job-hunting experience. It seemed that 90% of applications were asking all of the same voluntary personal questions - what's your gender, what's your ethnicity, are you disabled, are you Hispanic, what's your sexual orientation, etc.

He said he puts "choose not to disclose" or the closest option to that for every choice. He figured his answers could only hurt him, because he doesn't fit into any 'diverse' categories.

I was wondering, do the answers to these questions matter at all in terms of the candidate's chances of success? And moreover, why is any of this asked in the first place? I haven't applied for work formally in a long time, so this all came as a shock to see.