Peter Attia, MD & Carole Hooven, PhD Explain Why Testosterone Isn’t the Villain — It’s the Blueprint

This week on The Drive Podcast, Peter Attia, MD sat down with evolutionary biologist Carole Hooven, PhD for one of the most important — and misunderstood — conversations about testosterone you’ll hear all year.

 👉 Watch the full conversation here to understand why testosterone isn’t a moral problem, a social construct, or a “toxic” hormone — but a foundational biological signal that has shaped male development for millions of years.

What follows isn’t gym-bro hormone talk. It’s a deep, science-grounded explanation of why men and women differ on average, how those differences emerge before birth, and what happens when modern culture ignores that reality.

The Big Idea (Most People Miss This)

Testosterone’s most important effects happen before you’re born — not in adulthood.

By the time boys and girls are running around at age 5, their testosterone levels are nearly identical. Yet behavior is often dramatically different. Why?

Because prenatal testosterone permanently shapes brain development during narrow critical windows, long before parenting styles, school systems, or social media get involved.

This single insight reframes:

• Childhood behavior differences

• Why adult testosterone levels don’t predict personality well

• Why “socialization only” explanations fall apart

Key Insights You Probably Haven’t Heard Elsewhere

1. Testosterone Builds the Body and the Brain

Testosterone in the fetus reaches levels comparable to male puberty during the second trimester. During this time:

• It masculinizes reproductive anatomy

• It rewires neural circuits related to activity, aggression, risk-taking, and play

• These effects are permanent

This explains why:

• Boys show more rough-and-tumble play even before puberty

• Adult testosterone levels don’t explain childhood behavior

• You cannot “parent away” certain average sex differences

2. Rough Play Isn’t Toxic — It’s Training

Across mammals, male play fighting is adaptive. It teaches:

• Physical boundaries

• Hierarchy negotiation

• Conflict resolution without lethal violence

When boys lose physical play (replaced by screens), aggression doesn’t disappear — it often resurfaces later in more destructive forms.

This isn’t ideology. It’s evolutionary biology.

3. Testosterone Does NOT Equal Violence

Yes, men commit more violent crime — across every culture.
No, testosterone alone does not cause crime.

The conversation makes a crucial distinction:

• Biology creates predispositions

• Culture determines outcomes

Societies with strong norms and boundaries dramatically reduce violence without erasing sex differences. Ignoring biology doesn’t create peace — it creates confusion.

4. Estrogen Matters for Men (A Lot)

One of the most overlooked insights:

• Testosterone works with estrogen, not against it

• Blocking estrogen in men worsens mood, libido, and body composition

• Some masculine traits depend on estrogen signaling downstream of testosterone

This matters for anyone thinking about hormone therapy or optimizing health.

5. Fatherhood Changes Testosterone — On Purpose

When men bond with infants:

• Testosterone naturally declines

• Nurturing behavior increases

• Pair-bond stability improves

This isn’t weakness — it’s biological intelligence.
Hormones respond to life context, not just age.

ACTIONABLE TAKEAWAYS (What You Should Do Differently)

If You’re a Parent

• Stop panicking about rough play — supervise it, don’t suppress it

• Let boys resolve minor physical conflicts when safe

• Don’t assume identical treatment produces identical outcomes

If You’re Thinking About Testosterone Therapy

• Fix sleep, nutrition, body fat, and training first

• Numbers matter less than symptoms and context

• More testosterone ≠ better if estrogen is crushed

• Young men should be especially cautious — fertility can be permanently affected

If You Care About Health & Longevity

• Strength training matters for both sexes

• Hormones signal health status — they are not isolated levers

• Chronic inflammation, obesity, and stress suppress testosterone more than aging alone

Why This Conversation Matters

Much of modern discourse treats sex differences as either:

• Entirely cultural

• Or morally dangerous to discuss

Hooven and Attia make a third path clear:
👉 Biology is not destiny — but denying biology guarantees bad outcomes.

Understanding hormones doesn’t limit human potential.
It allows us to work with reality instead of fighting it.

Subscribe to the Wellness Rollup today!