Competition among human females likely contributed to concealed ovulation

Humans are among the few species that lack overt physical indicators of female fertility. One explanation for concealed ovulation in human females is that hiding fertility from males helps females secure resources from males for raising children. A new model developed by a team of evolutionary scientists casts doubt on this idea, showing that females might have evolved to conceal ovulation from one another, not from males.

Jealous feelings can act as a tool to strengthen friendships

Jealousy can be important for maintaining friendships, which are crucial to physical and emotional health. A study conducted by scientists at Arizona State University, Oklahoma State University, and Hamilton College found feelings of jealousy were sensitive to the value of the friendship and motivated behaviors aimed at keeping friends.