THEY ARE AS FOLLOWS: (1) THE ENVIRONMENTAL HYPOTHESIS STATES THAT POLITICAL VIOLENCE IS LIKELY TO OCCUR UNDER CONDITIONS OF MIDDLE-LEVEL SOCIAL MODERNIZATION AND FRAGMENTED POLITICAL CULTURE; (2) THE INSTITUTIONALIZATION HYPOTHESIS STATES THAT POLITICAL VIOLENCE IS LIKELY TO OCCUR WHEN THE DIFFERENTIATION AND DURABILITY OF POLITICAL STRUCTURES ARE LOW; AND (3) THE FINAL HYPOTHESIS STATES THAT VIOLENCE BREEDS VIOLENCE AND GOVERNMENTAL INSTABILITY. OF THE COUNTRIES SELECTED FOR THIS PRELIMINARY ANALYSIS, 14 ARE ANGLO-SAXON AND WESTERN EUROPEAN, 12 ARE MIDDLE EASTERN AND NORTH AFRICAN, 11 ARE BLACK AFRICAN, 9 ARE LATIN OR CENTRAL AMERICAN, 10 ARE EAST ASIAN, AND 6 ARE EUROPEAN COMMUNIST. COUNTRIES THAT HAVE PARLIAMENTARY OR PRESIDENTIAL REPUBLICAN FORMS OF GOVERNMENT TOTAL 29. THE REMAINING 34 ARE RATHER EVENLY DIVIDED AMONG COLONIAL, MILITARY, 'PERSONALISMO,' RULING MONARCHICAL, SINGLE-PARTY (NONCOMMUNIST) EXECUTIVES, AND COMMUNIST. THE DATA ARE MAINLY FROM CIRCA 1965 AND ARE COMPRISED OF 25 VARIABLES SELECTED AS 'CANDIDATE-INDICATORS'. THEY INCLUDE RIOT EVENTS, PROTEST DEMONSTRATION EVENTS, ARMED ATTACK EVENTS, INTERNAL SECURITY FORCES PER 10,000 WORKING-AGE POPULATION, IRREGULAR POWER TRANSFER EVENTS, AND MAJOR OR MINOR GOVERNMENTAL CHANGE EVENTS. FACTOR ANALYSES WERE USED TO DISCOVER WHICH VARIABLES WERE CLOSELY RELATED TO EACH OTHER. FINDINGS INDICATE THAT NONE OF THE MAIN ENVIRONMENTAL OR INSTITUTIONAL PHENOMENA TESTED EXERT SUBSTANTIAL INFLUENCE ON POLITICAL VIOLENCE AND INSTABILITY, ALTHOUGH SOME APPEAR TO CONTRIBUTE TO THE SETTING FOR THESE TWO CONDITIONS. A BRIEF ANALYSIS OF THE UNITED STATES CONCLUDES THAT, IN ABSOLUTE TERMS, THIS COUNTRY WAS ONE OF THE MOST POLITICALLY VIOLENT COUNTRIES IN THE WORLD BETWEEN 1945 AND 1965; IT HAS MAINTAINED THAT POSITION TO THE PRESENT TIME (1970). TABLES, REFERENCES, AND AN APPENDIX ARE INCLUDED. (PRG)