Ed Hagen is a professor of anthropology at Washington State University Vancouver. During our conversation, Ed talks about the evolutionary reasons for two of humanity's most common mental illnesses: anxiety and depression. He also talks about psychic pain, the correlation between grip strength and depression, hypervigilance and anxiety, differences in suicide rates between men and women, and suicide attempts being an "honest signal of need."

Ed has noted that depression is commonly "intertwined with social conflict" and is a legitimate indication of a threat to one's biological fitness. Millions suffer every day from a poor or an intolerable psychological state. Ed's work and his original ideas are a potential corrective to the common view that psychological ill-health is due primarily to a "chemical imbalance." He encourages us to look deeper, to take a more comprehensive look, and to use an evolutionary lens to begin to try to both understand and help alleviate unnecessary suffering.