Arguments can be both rational and irrational but they are quite necessary for various reasons. In every relationship there should be some space for an argument. People argue mainly when they have a difference in opinion and want their point to be taken seriously. Arguments can clarify your doubts and disillusions. It is always better to express your original opinions instead of just agreeing with what others have to say. People also argue when they face an intellectual hindrance. If there is something you do not believe or if questions arise in your mind regarding a matter you may start an argument with someone who is a staunch believer of the same matter.
When it comes to couples, they argue about a lot of different things. Two people, who live together, under the same roof, need to compromise on many points. Every time we compromise we tend to feel dissatisfied. Such dissatisfaction makes us prone to argue with our partners over small issues. It is actually good to vent out our pent up emotions through arguments. Some couples do not talk it out and let the emotions get stored in the form of frustration and anger. This can lead to emotional detachment and break ups.
Couples and family members argue over a ton of different things. The sharing of chores and family responsibilities are always a reason for argument. The right way of bringing up kids is often the reason of argument between parents. Money is another great argument starter. Couples argue over expenses and mortgages. People also argue about social matters like religion and politics. Another very common topic for argument is sex. Couple fight over sexual matters when one is eager to be intimate yet the other partner does not respond with matching gusto.