People with more sexual partners or casual relationship histories are judged less favorably, with men receiving harsher evaluations than women for similar sexual behaviors, according to new research.

Do narcissists overestimate how much others like and admire them? New research explores narcissists' metaperceptions in social interactions.

A new study suggests that pregnant women are more likely to claim their fetus resembles the father, even during early ultrasounds when no real resemblance is visible. The behavior may be an evolved strategy to reduce paternity uncertainty and secure investment.