Age- and gender-related differences in number of suicides: Siberian example as an illustration of the universal pattern and impact of socio-economic factors

Olga Gritsenko, Ksenya Ocheretnaya

Psychology Faculty of Novosibirsk State University, and Research Institute for Molecular Biology and Biophysics, Novosibirsk, Russia

Despite differences between industrial countries in culture and national prosperity, the demographic features of suicide in these countries seem to be very similar. In particular, the pattern of suicide is universal in that 1) suicide rate is low before 10, 2) the rate rapidly increase in males after 15, and 3) the rate in women is low compared to that in men (see, i.e., Linden & Breed, 1976, Figures on pp. 92, 93). This does not mean that the suicide pattern might not be modified to some extent by several socio-economic factors. However, both universal features and modifications of the suicide pattern would be easily explained in evolutionary psychology perspective. This study is designed to analyze the age- and gender differences in the number of suicides in Novosibirsk.

When we discussed this project with Frank Salter and Arcady Putilov, Frank Salter pointed at the increased rate of suicide in old men in the United States. This might be, in particular, explained by their unwillingness to bother the younger relatives and understanding their uselessness for the society and family. Indeed, the numerous problems of old men related to bad mental and somatic health, need for permanent care, etc. could make problematic their ability to increase further their inclusive fitness. Instead, due to the considerable need for help and investments in their health and support, they more likely could decrease their inclusive fitness. Arcady Putilov suggested that number of suicides among old Siberian men would be low due to demographic specificity of Russian population. Life span expectation for a Russian man is very short compared to that of Russian woman (the latter unlike former has almost the same life expectation as people of western countries). Russian men from the group of suicide risk would die earlier, i.e. due to alcohol intoxication and related diseases and accidents. By contrast, Russian old women would be more prone to commit suicide due to the same reason as American old men. In fact, the problems of the Russian women and their relatives were multiplied by considerable drop in family income in the last decade.

To test this suggestion we compared number of suicides in males and females of different age groups. In total, we analyzed 1023 cases for 2001 in Novosibirsk Region (Appendix). The general demographic features of the suicides in Novosibirsk were similar to that in western countries. However, the predominance of men in suicide statistics was clear only till the age of 75. Thereafter, the difference between genders disappeared. This means the considerable decrease in the number of suicides among men and stabilization of the level of suicides in women of the oldest age groups. Thus, the data confirm the suggestion of universality of most general features of suicide pattern and modifying effect of country-specific social factors on suicide statistics in the particular age group of Siberian people. More detailed analysis of suicide statistics, i.e. in relation to such factors as marital status, employment, social support, family income, etc. is necessary for further clarifying and understanding the reasons for differences between the patterns observed in Siberia and other regions of the world.