How most inter-personal fights start

I've been thinking about inter-personal relationships and fights for a while now, and have observed over the last few years a number of large and small fights between colleagues, friends and family. What I've noticed is that many of these fights follow a very predictable pattern. It goes like this.

Step 0: Person A and Person B are going along quite happily as friends, family or colleagues.

Step 1: Person A does something without really thinking that offends Person B. Person B may have had a right to be offended, or may not, it doesn't make much difference. Person A had no intent to do malice or harm, and does not even realize that Person B was offended. Person B however is horribly offended and cannot believe that Person A just attacked him for no good reason at all.

Step 2: Person B responds angrily to Person A and tells him just what he thinks of him. How dare Person A do such a thing!

Step 3: Person A is now horribly offended. From his perspective he did nothing wrong, and suddenly Person B is now accusing him of all sorts of hateful things. Person A responds badly to Person B and raises the anger level higher.

Step 4: Person B is now really steaming. Not only did Person A start this whole fight,but when B pointed this out to him, Person A not only didn't apologize, but was rude again! Unbelievable. Now Person B really gives it to Person A, as he deserves.

Step 5: Now Person A is really steaming. Not only did Person B completely attack him out of the blue once before for no good reason, he is now attacking him again rather than apologizing. Unbelievable! Person A really gives it to Person B, as he deserves.

Step 6-100 repeat.