Here’s a finding that everyone basically already knows—men prefer dating younger women. Researchers from two universities looked at the dating profiles of 120,000 eHarmony users. They found one in five British men, or 20 percent, are in a relationship with a woman five years younger, citing looks and health as key factors for choosing younger women. However, men who are fathers were found to be more open to dating women their own age, as their priorities and core values change. The data also found that on average, women prefer dating men at least 18 months older, citing emotional maturity and a desire for a committed relationship. When the researchers looked at the UK population as a whole, they found the average age gap between a woman and her partner is 20 months. However, men who did not want children had no age gap with their female partners—the researchers say this could be due to the subconscious belief that women around age 25 have the highest fertility.