**6. Discussion**

Recent years have seen a rise in the political gender gap; women in Western European countries have gradually preferred more leftist parties [55]. In the United States, the share of women who identify with or lean toward the Democratic Party has increased. The last data from the Pew Research Center [56] show that among registered voters, 56% of women affiliate or favor the Democratic Party compared to 44% of men. Several authors have hypothesized that the difference between women and men on political attitudes and political party identification can be attributed to differences in SDO [5]. To investigate if the gender gap in politics goes deeper than traditional left-wing and right-wing division, we analyzed gender differences in SDO in activists of HE and HA political parties. According to the gender invariance hypothesis, all else been equal, men should still have significantly higher SDO than women. The predisposition of males to be temperamentally inclined to dominate will produce nonetheless residual gender differences even among males and females belonging to groups who uphold egalitarian group values.

To analyze the gender invariance hypothesis in a political context, we based our study on political activists. Political activists, in fact, not only identify with groups that hold specific hierarchy-enhancing or hierarchy-attenuating ideologies but actively participate, promoting their values and ideas within the group. Their active commitment in specific HE or HA groups should encourage in fact, even more, the internalization of legitimizing myths that may influence their levels of SDO. Our research was based on four samples of male and female activists belonging to hierarchy enhancing – right-wing – vs. hierarchy attenuating – left-wing - political groups. According with SIT and SDT, the SDO scores should be higher in right-wing groups than left-wing groups and highest in extreme rightwing groups and lowest in extreme left groups. However, according to SDT, even while absolute levels of SDO may vary across situations, men should still have significantly higher SDO than women. The SIT theory, on the contrary, would predict that groups on both sides of the political divide should attract males and females who, for the left, are strong egalitarian and do not favor the oppression of one group over another and, for the right males and females, who hold equally strong opposite views. Gender differences should be insignificant since egalitarian adult socialization

experiences should promote egalitarian attitudes in both men and women activists and vice versa.

On the whole, our results sustain more the validity of the soft than the strong version of the invariance hypothesis [25]. We observed general differences in SDO score across political groups (e.g., SDO score for right-wing were higher than leftwing); therefore, males of all the activists' groups showed a higher social dominance than females invariantly belonging to left- or right-wing political groups. The soft version implies indeed that SDO difference between men and women should be essentially constant across cultural and situational factors, everything else being equal. Our study confirmed that SDO differentiated men and women invariantly across cultural and situational factors such as political activism practiced both in moderate and extremist political groups. Male right-wing extremists had the highest SDO scores and female left-wing extremists the lowest. Still, the gender differences persisted in all groups, giving strong support for the temperamental differences in dominance predisposition.

Our data did show also that extreme right-wing women presented significantly higher scores of SDO than men belonging to left-wing parties. This result can be congruent with both SIT and SDT, which emphasizes the importance of group identification and the soft version of the SDO gender hypothesis that recognizes the influence of context.
