24 August 2026
The Scientist Who Scans Fathers' Brains: Parenthood Shrinks Your Brain, And Drops Testosterone 25%!
The Diary Of A CEO with Steven Bartlett
About
What actually happens to your brain, and how fast or slow do you age when you become a parent? Dr. Darby Saxbe reveals the surprising science of the "parental brain" and how fatherhood physically reshapes a man's mind, why dads lose grey matter, what really happens to testosterone, and why the "dad bod" might be nature's design.
Dr. Darby Saxbe is a professor of psychology and a leading researcher on the neuroscience of parenthood. She is the founder and director of the NEST (Neuroendocrinology of Social Ties) Lab at the University of Southern California, where her pioneering work studies how the transition to parenthood changes the brains, hormones and relationships of both mothers and fathers. Her research has reshaped how scientists understand fatherhood, men's mental health, and what it really takes to raise a child.
Chapters
00:00:00 Intro
00:02:13 Role Of Fathers In Parenting
00:06:10 What Happens To The Brain When You Become A Father?
00:09:09 Why Testosterone Drops When Men Become Fathers
00:11:22 Should Men Be Worried About Lower Testosterone?
00:15:39 What Fatherhood Can Change In A Man’s Personality
00:19:00 The Upsides And Downsides Of Parenting
00:21:30 What Happens When We Make Parents Fight?
00:23:48 Why The Birth Experience Can Shape Your Relationship
00:27:25 Are People Waiting For The Perfect Time To Have Kids?
00:30:44 Why Fewer People May Be Choosing Parenthood
00:35:12 Ads
00:37:34 Do Parents Actually Have Healthier Brains?
00:45:02 What Does Daycare Really Mean For Children?
00:47:17 Why Mothers Become The Default Parent
00:49:10 Maternal Gatekeeping And Weaponized Incompetence
00:52:04 What Really Happens To Relationships After A Baby
00:54:27 Why Fathers Can Experience Postpartum Depression
00:56:45 Can Your Personality Predict Whether You’ll Divorce?
01:00:51 Why Women’s Ovulation May Be Harder To Detect
01:03:06 How Can You Increase Your Chances Of Conceiving?
01:04:03 What Every New Father Needs To Know
01:04:51 Ads
01:05:51 How Should Parents Divide Baby Care?
01:07:54 What Couples Should Do Before Having Kids
01:13:26 How To Protect Your Relationship After Having Children
01:15:24 Is The Dad Bod More Attractive?
01:18:36 What Does Your Childhood Teach You About Parenting?
01:20:30 How Divorce Can Affect Children
01:20:47 Are Humans Really Meant To Be Monogamous?
01:22:09 What Are The Biggest Concerns About Modern Parenthood?
01:23:54 What Systemic Change Could Transform Parenting?
She explains:
◼ Why a father's brain physically shrinks when you become a dad
◼ Why testosterone drops in new fathers
◼ Why the "dad bod" may signal a more attentive hands-on father
◼ Why men experience postpartum depression
◼ Why raising a child was never meant to be done by two people alone
Follow Dr. Darby Saxbe:
X: https://x.com/darbysaxbe
NEST Lab: https://www.nestlab.ca
Her research: https://dornsife.usc.edu/nestlab/
Her book ‘Dad Brain: The New Science of Fatherhood and How It Shapes Men's Lives: https://a.co/d/03Qhspxt
Join her US based ‘Daddy Stroller Social Club’: https://daddystrollersocialclub.com
The Diary Of A CEO:
◼ Join DOAC circle here - https://doaccircle.com/
◼ Shop The Diary Of A CEO collection: https://thediary.com/collections/shop (https://link.thediaryofaceo.com/5IB1H6E)
◼ Get email updates - https://link.thediaryofaceo.com/5IB1H6E
◼ Follow Steven - https://link.thediaryofaceo.com/AGU9QP4
Sponsors:
Shopify - https://shopify.com/bartlett
Linkedin Talent Solutions - http://linkedin.com/DOAC
Pipedrive - https://pipedrive.com/CEO
Dr. Darby Saxbe is a professor of psychology and a leading researcher on the neuroscience of parenthood. She is the founder and director of the NEST (Neuroendocrinology of Social Ties) Lab at the University of Southern California, where her pioneering work studies how the transition to parenthood changes the brains, hormones and relationships of both mothers and fathers. Her research has reshaped how scientists understand fatherhood, men's mental health, and what it really takes to raise a child.
Chapters
00:00:00 Intro
00:02:13 Role Of Fathers In Parenting
00:06:10 What Happens To The Brain When You Become A Father?
00:09:09 Why Testosterone Drops When Men Become Fathers
00:11:22 Should Men Be Worried About Lower Testosterone?
00:15:39 What Fatherhood Can Change In A Man’s Personality
00:19:00 The Upsides And Downsides Of Parenting
00:21:30 What Happens When We Make Parents Fight?
00:23:48 Why The Birth Experience Can Shape Your Relationship
00:27:25 Are People Waiting For The Perfect Time To Have Kids?
00:30:44 Why Fewer People May Be Choosing Parenthood
00:35:12 Ads
00:37:34 Do Parents Actually Have Healthier Brains?
00:45:02 What Does Daycare Really Mean For Children?
00:47:17 Why Mothers Become The Default Parent
00:49:10 Maternal Gatekeeping And Weaponized Incompetence
00:52:04 What Really Happens To Relationships After A Baby
00:54:27 Why Fathers Can Experience Postpartum Depression
00:56:45 Can Your Personality Predict Whether You’ll Divorce?
01:00:51 Why Women’s Ovulation May Be Harder To Detect
01:03:06 How Can You Increase Your Chances Of Conceiving?
01:04:03 What Every New Father Needs To Know
01:04:51 Ads
01:05:51 How Should Parents Divide Baby Care?
01:07:54 What Couples Should Do Before Having Kids
01:13:26 How To Protect Your Relationship After Having Children
01:15:24 Is The Dad Bod More Attractive?
01:18:36 What Does Your Childhood Teach You About Parenting?
01:20:30 How Divorce Can Affect Children
01:20:47 Are Humans Really Meant To Be Monogamous?
01:22:09 What Are The Biggest Concerns About Modern Parenthood?
01:23:54 What Systemic Change Could Transform Parenting?
She explains:
◼ Why a father's brain physically shrinks when you become a dad
◼ Why testosterone drops in new fathers
◼ Why the "dad bod" may signal a more attentive hands-on father
◼ Why men experience postpartum depression
◼ Why raising a child was never meant to be done by two people alone
Follow Dr. Darby Saxbe:
X: https://x.com/darbysaxbe
NEST Lab: https://www.nestlab.ca
Her research: https://dornsife.usc.edu/nestlab/
Her book ‘Dad Brain: The New Science of Fatherhood and How It Shapes Men's Lives: https://a.co/d/03Qhspxt
Join her US based ‘Daddy Stroller Social Club’: https://daddystrollersocialclub.com
The Diary Of A CEO:
◼ Join DOAC circle here - https://doaccircle.com/
◼ Shop The Diary Of A CEO collection: https://thediary.com/collections/shop (https://link.thediaryofaceo.com/5IB1H6E)
◼ Get email updates - https://link.thediaryofaceo.com/5IB1H6E
◼ Follow Steven - https://link.thediaryofaceo.com/AGU9QP4
Sponsors:
Shopify - https://shopify.com/bartlett
Linkedin Talent Solutions - http://linkedin.com/DOAC
Pipedrive - https://pipedrive.com/CEO