World An odorless chemical in babies causes women to be aggressive, but men not to be. Here’s why. November 22, 2021November 23, 2021 Jordan Mendoza, USA TODAY Comments Off on An odorless chemical in babies causes women to be aggressive, but men not to be. Here’s why. A chemical found on newborn babies' heads called hexadecanal, or HEX, triggers men to become less aggressive but women to become more aggressive.