The analysis of almost 500 unofficial names of the inhabitants of Olszowa and Palesnica (Tarnów district) showed how the studied population perceives the world. Their thinking is dichotomous and leads to the division of the world in two categories 'natives' (whose character is not ridiculed in nicknames) and 'strangers'. This dichotomy values 'natives' and deprecates 'strangers'. The group of 'strangers' is constituted not only by those who moved into the area or appeared in the community by getting married. Those who behave asocially or use a language considered as unnatural (speak in local dialect in official situation or try to get rid of a dialect in unofficial contacts) also fell into this category. In the unofficial nicknames the negative emotions are signalled not only by definitional and implied semantic content but also by expressive endings and affixes. The use of animal names in nicknames (which introduces 'homo' - 'animal' dichotomy) plays role in deprecation and dehumanisation of people as well.