In some cases, estate disputes start because of sibling rivalry. The way that kids have related to each other all their lives can continue even into adulthood. This can make them compete with one another or resent each other. Those feelings come back up when they do not agree with a will or estate plan.
Plus, their parents have now passed away, leaving a leadership void. While Mom and Dad may have been good at handling their kids and their different personalities when they were alive, the children may not know how to do that on their own.
One reason for sibling rivalry is just that kids have different temperaments. Their dispositions, moods and personalities are all unique.
A second child may always assume that the firstborn is the favorite, for example, and that child may become insecure and aggravated by this, even if it's not true. The firstborn, meanwhile, could become arrogant -- just making things worse.
When those two read the estate plan, if the bequests are unequal and the firstborn gets more, the second child takes this as a sure sign that they were right all along: That child was the parents' favorite. They feel slighted and angry, and they lash out. All of those years of conflict as kids suddenly come rushing back, even if they are now in their 60s and should be done with such things.
This is just one way of many that an estate dispute can take place. Those who find themselves involved need to know what steps to take and what rights they have.