I'm a history student and this was one of the questions we got asked this year in our 'History of Violence' module. This probably isn't the answer you wanted to receive but to be honest it's difficult to say, because it depends how you look at it. For example, there was a lot more a risk of being murdered as you went about your daily life then, just because we didn't have as many safety measures then as we do now (street lamps, cameras etc.), and it goes without saying that punishment was a lot more violent in the Middle Ages and you were punished severely for minor things. But if you look at the last century alone for example, we've had two world wars, genocide and have had the threat of nuclear war. In my opinion at least, while people in the Middle Ages faced a lot of violent behaviour, it wasn't able to be carried out on the same scale as it is today. If you take an average bomb from an aircraft as an example, it's capable of doing a lot more destruction from quite a large distance away than say close quarters combat with swords. It's also capable of killing more people in a shorter amount of time.

While it is quite controversial and I don't necessarily agree with his theories, Steven Pinker wrote a book called 'The Better Angels of our Nature'. http://en.wikipedia.org/wiki/The_Better_Angels_of_Our_Nature Basically, he argues that over time we have gotten less violent. But looking at the Middle Ages specifically, he says they WERE violent because of religious intolerance, the government was divided between barons, knights etc. so there was a lot of fighting to regain power, and he also mentions how a lot of entertainment in the Middle Ages had an element of torture - such as jousting or animal baiting. But he describes the Middle Ages as fairly civilised and thinks they were less violent than humans prior to the Middle Ages.

Finally, it sort of depends on what you consider 'violence'. Do you consider it physical violence such as murder alone? Or is persecution and prejudice violent behaviour too? Does violent behaviour include slaughter of animals, or just against humans?

I hope I managed to at least attempt to answer your question. Like most things in history there's different ways of looking at a topic and no definite answer!