Two samples (Russian, n = 155 and Chechen, n = 184) were used to study the differences in the temperament scales using the "Eysenck Personality Questionnaire" and the peculiarities of the central nervous system functioning using the computerized chronoreflexometry method. Ethnic and gender differences are identified between Russian and Chechen nationals. Chechen men are less extroverted than Russian men. Ethnic differences in extraversion and introversion are less pronounced among women. The level of neurotism in Chechen men, as well as in women, was lower for choleric men and higher for phlegmatic men compared to Russians. Changes in personality properties correlate with changes in the properties of the CNS in the number of preemptive response, differentiation errors, time, and level of formation and stability of sensorimotor responses, which can be considered as markers of a certain type of temperament.