For about three quarters of a century the Jeninites have procreated between themselves in their close-knit population. A similar situation in Gaza. In consequence, you had the genius offspring like the eldest Sinwar Sibling, that lead them to death and destruction. By excluding the politically and genetically the non-jihadis, they have destined themselves into very stunted future. In example, for each opponent they through off the roofs, there was a future weakening of the society.