territory (such as by discouraging immigration or encouraging flight) Subjugation of a particular population (such as lynching of African Americans) Spread or dominance of a particular religion – religious terrorism Ending perceived government oppression Responding to a violent act (for example, tit-for-tat attacks in the Israeli–Palestinian conflict, in The Troubles in Northern Ireland, or Timothy McVeigh's revenge for the Waco siege and Ruby Ridge incident) Causes for right-wing terrorism have included white nationalism, ethnonationalism, fascism, anti-socialism, the anti-abortion movement, and tax resistance. Sometimes terrorists on the same side fight for different reasons. For example, in the Chechen–Russian conflict secular Chechens using terrorist tactics fighting for national independence are allied with radical Islamist terrorists who have arrived from other countries. Personal and social factors Various personal and social factors may influence the personal choice of whether to join a terrorist group or attempt an act of terror, including: Identity, including affiliation with a particular culture, ethnicity, or religion Previous exposure to violence Financial reward (for example, the Palestinian Authority Martyrs Fund) Mental health disorder Social isolation Perception that the cause responds to a profound injustice or indignity A report conducted by Paul Gill, John Horgan and Paige Deckert found that for "lone wolf" terrorists: 43% were motivated by religious beliefs 32% had pre-existing mental health disorders, while many more are found to have mental health problems upon arrest At least 37% lived alone at the time of their event planning and/or execution, a further 26% lived with others, and no data were available for the remaining cases 40% were unemployed at the time of their arrest or terrorist event 19% subjectively experienced being disrespected by others 14% percent experienced being the victim of verbal or physical assault Ariel Merari, a psychologist who has studied the psychological profiles of suicide terrorists since 1983 through media reports that contained biographical details, interviews with the suicides' families, and interviews with jailed would-be suicide attackers, concluded that they were unlikely to be psychologically abnormal. In comparison to economic theories of criminal behaviour, Scott Atran found that suicide terrorists exhibit none of the socially dysfunctional attributes—such as fatherless, friendless, jobless situations—or suicidal symptoms. By which he means, they do not kill themselves simply out of hopelessness or a sense of 'having nothing to lose'. Abrahm suggests that terrorist organizations do not select terrorism for its political effectiveness. Individual terrorists tend to be motivated more by a