Why do girls smell their boyfriends?
The theory is that individuals are subconsciously attracted to the body odors of potential partners with dissimilar MHC genes. This preference is believed to be detected through scent, which serves as a cue for genetic compatibility. Several studies have supported the idea that MHC-related odors influence mate choice. They found certain scent compounds in female body odor increased during ovulation and can subtly influence how men feel. When these scents were added to armpit odor samples, men rated them as more pleasant and faces associated with the samples as more attractive.