When adult siblings are continually at one another's throats, the conflicts have often been set up, either openly or covertly, by the behavior of one or both of the parents over an extended period of time - usually dating back to the siblings' childhood. Such parental behaviors are particularly effective for this purpose if started when the children were very young and have been continued, with minor variations, throughout their lives. There are a number of relatively straightforward techniques for parents to accomplish this goal. Here are a few common ones; there are undoubtedly a whole lot more.1. The parent gossips and complains about each sibling behind that sibling's back to the all the rest of the other siblings.2. The parents make constant negative comparisons of one sibling with another. For example, they might repeatedly scream, "Why can't you be more like your brother?!?"3. The parent consistantly focuses only on those siblings who are creating repetitive, ongoing problems for themselves - and for everyone else in the family - and pays no or minimal attention to the siblings who are doing well and who are functioning independently.4. Parents may leave the bulk of their estate to one or two siblings after they pass away, and much less - or even a pittance - to the rest. This is especially effective if they give almost all the money to the biggest screw up, or to the ones that did not come over and help take care of them when they were sick or indisposed in some way.The picture at the top of the post are musician Frank Zappa's wife Gail and his two sons, Ahmet and Dweezil. Although there is no way to be certain from news stories orTwitter wars, a recent public feud in the family might possibly be an example of what I'm talking about. According the the Los Angeles Times: "Frank Zappa’s rich musical and cultural legacy, and which children have a right to profit off it, have recently become the subject of a public and contentious family battle. The children of Frank and Gail Zappa – Moon Unit, Dweezil, Ahmet and Diva – were left unequal shares of the Zappa Family Trust, which owns the rights to a massive trove of music and other creative output by the songwriter, filmmaker and producer — more than 60 albums were released during Zappa’s lifetime and 40 posthumously. Thanks to a decision by their mother, who died in 2015, Ahmet, 42, and his younger sister, Diva, 36, share control of the trust — to the dismay and anger of their two older siblings, Dweezil, 46, and Moon, 48, who received smaller portions."