Dads Still Have That Prehistoric Biological Push
“The nurse showed him how to change a diaper in the hospital, and it was his first time ever. He had never held a newborn, never changed a diaper, but from the moment he became a dad, he just naturally did it—swaddling, everything.” — New Mom
So why did this tough, survival of the fittest champ settle down and make huge sacrifices for his family? Brain research has given us answers: Turns out, Cave Dad was fine-tuning his biology to further support fatherhood. He then passed on to his sons, and all descendent dads thereafter, something very special: the paternal drive to protect and care for their family and the instincts to do it well.
Even before his baby’s arrival, Dad’s body starts producing “fatherhood” chemicals that trigger vital changes, including a sharpened awareness of danger, especially in the last month of pregnancy. His brain has more to do once the baby is born, so it installs a “performance chip” for a massive boost. It also cues Dad and Baby brains to link up and grow in a pattern that continually strengthens their relationship: bonding at its finest!
READ! Dad’s Secret Superpowers
"I'm a heavy sleeper, and my wife used to say you could drive a bus through our bedroom and I wouldn't wake up, but when our daughter was born it was like—snap—you’re up. It's some sort of genetic programming."
— New Dad

Cortisol
Driving to the doctor, you may spot some aggressiveness from Dad if another car inches too close to yours. Or he might start pondering which off-road vehicle is best if the zombie apocalypse starts. Cortisol keeps Dad alert and tuned-in to his baby’s cries and ensures he’s on the job.
Prolactin
Prolactin sparks Dad’s instinctual drive to care for his child. It launches during pregnancy and strengthens after childbirth through hands-on baby care. Prolactin is considered a stress hormone since it's released in response to threats.
Testosterone
At birth, testosterone drops down for about six weeks, which helps Dad ease up and develop paternal patience. Testosterone also supercharges Dad’s reflex to protect his child and surges when he hears a screaming baby: Daddy to the Rescue!
READ! Dad Bods & Dad Brains
“With dads, the more interaction they get with the baby the stronger their bond becomes."
- New Mom
"Honestly, do as much as you can to help. It's the best thing in the world because the bond I have with him now is incredible. Absolutely incredible."
- New Dad