Abstract Scores on 24 syntality dimensions for 100 modern nations have recently been made available by Cattell and Woliver (1979). For 18 of these countries population samples were measured on the 16 P.F. (translated). Significant differences appeared among countries on various personality factors. Correlations were then worked out between the personality factors (16 primaries and 2 secondaries, exvia and anxiety) and the syntality factors. A greater than chance expectation were significant at the p <.01 and p <.05 level for the best replicated syntality dimensions. Actually the theoretical model, S = f (R.P) would not call for any simple relation between syntality, S and population traits, P, but in this case the 18 countries are similar “developed” countries in structure, R, to permit expectation of S relations to P. The relations found, which are discussed in detail for the 8 syntality factors based on firmest evidence, make excellent psychological sense. Mainly, deviations on two or three different personality factors can be seen as sustaining the group behavior evidenced in a syntality dimension; but throughout most instances a two-way causal action seems the best explanation. A much briefer listing is given of the remaining syntality connections (most of which are only at the statistical level of indications), to suggest hypotheses for further more intensive investigation. Some discussion is given to (a) effects of methodological limitations in the present study and (b) refinement of the concepts involved, particularly of cultural pressure, vigorous adapted development, intelligent affluence and political-cultural alertness.