You can judge that when your interview is being conducted. I once encountered a really ill-mannered person once. He was talking to me as if I owe something to him. Having said that, a person could be judged when you meet them for the first time.
There is a possibility you are going to find out from how the person treated you when you are being interviewed but there is also a chance that the business owner might not even be among the ones who are interviewing those who are about to be employed to work for the business.