RÉSUMÉ
National or Caste group characteristics typify psycho-social characteristics of that group. These typifying psycho-social characteristics, whether of individuals or of families or of small or big groups, have tremendous predictive value in determining interventional outcomes. Systematic studies to discern distinguishing features of population subgroups vis-à-vis domicile, socio economic status (SES), gender etc. practically non-existent. . Psycho-social characteristics determine behavioural expressions in day to day living. In a separate large scale study entitled “A Study of the Impact of Behavioural Interventions on Illness Breeding Behaviors” funded by World Bank through Uttar Pradesh Health System Development Project; Lucknow, 1134 families drawn on stratified random basis from rural and urban areas of Barabanki, Mujaffarnagar and Gorakhpur districts of Uttar Pradesh (Northern India) were studied along various psycho-social characteristics to study the differences, if any, between the population subgroups. The data revealed significant differences between the population sub-groups along several psychosocial characteristics. The findings are discussed.