Verism seems to be very prevalent in Roman culture. First, I believe they had the technology to improve on the earlier culture’s art and they had the skill that was needed to make very detailed artwork. This would have made it easier for both the artisan and also the person they were trying to portray.
Secondly, I believe they looked at previous cultures and decided they wanted to be known for their art. It seem to have been very important to them. By making it real, so to speak, it was a representation of not only them but of their culture. When you are borrowing ideas from someone, you want to improve on them. They borrowed from the Greeks and to go them one better, they wanted their art to reflect not only their culture but their skill. This would have been the sincerest form of flattery to the individual portrayed.
We have done similar things in our culture, we’ve worked to improve designs in engineering, architecture, and technology. Someone may have done it before us but we want to make it our own and improve on it. It applies to art also. We want to do it better than anyone else. It is not only a sense of pride, but a sense of improving on an object. We take pride in ourselves and the work we do.