People trust others with dilating pupils and withhold trust from others with constricting pupils; moreover,peoples' own pupils mimic changes in their partners' pupils.

This statement is true. Research has shown that people tend to trust others with dilated pupils, which can be a sign of attraction, excitement, or interest. Conversely, people are more likely to withhold trust from others with constricted pupils, which can be a sign of anxiety or disinterest. Additionally, people's own pupils tend to mimic changes in their partner's pupils, which is believed to foster feelings of connection and empathy.