One summer evening,

my eighteen-year-old son Jimmy
said he wanted to talk.

So, after my wife Joan and I got his three
much younger siblings tucked in

and read their bedtime stories,

Joan and I sat down in our bedroom.

Jimmy came in and closed
the door behind him.

And he sat down on a chair across
from the bed where we were sitting,

and says, "Mom and Dad,
I have something important to tell you,

and it's not a problem, it's not
a bad thing, it's just different."

We said, "Okay."

And he looked at us in earnest,
and he said, "I'm gay."

So, after a few seconds
of deafening silence,

Joan takes a deep breath and says,
"Jimmy, we will love whoever you love."

That was about 12 years ago
when he came out to us,

and I'll have to admit that, at the time,

Joan and I did think
this could be a problem,

for his safety, even.

And as his father, I had this feeling
that, somehow, I had failed him,

and maybe, because of that, he wouldn't
have a chance to have kids of his own.

So, I'm a cardiologist,

and I like to imagine the world through
the eyes of a hunter-gatherer ancestor

for clues about how to thrive
in the modern world,

but, viewed in the light of evolution,

homosexuality seems to be a real
self-defeating non-productive strategy.

I mean, gays have 80% fewer kids
than heterosexuals.

This is a trait that ought to go extinct
in a few generations,

but down through recorded history,

in every culture,
and many animal species as well,

homosexuality's been a small,
but distinct subgroup.

If this were a genetic error,

natural selection should have long ago
called this from the gene pool.

So, while I was pondering this,

this paradox about the natural
origins of homosexuality,

our babies grew up.

Jimmy has three younger
siblings who adore him.

He has this magnetism 
and this charming wit

that helps them feel happy and relaxed.

And one day, while contemplating
this "Jimmy effect,"

it suddenly dawned on me:
homosexuality is not so much about sex;

it's really more about survival,
the family's survival.

So us, Homo sapiens, we are among
the most social species on Earth.

For us, it's not just a kill-or-be-killed
struggle for existence.

It's a snuggle for existence, you know.

An ability to love our family
and bond with our group

determines, in many cases,
whether we survive or perish.

So it's the survival
of the fittest family,

not the fittest individual.

So, you share 50% of your DNA
with your siblings.

Your nieces and nephews
share 25% of your DNA.

Frоm evolution's perspective,

you have the same genetic success
if you raise one child on your own

or you enable a sibling
to raise two children.

Frоm evolution's perspective,

this is all about 
cooperation and altruism.

Homosexuality is
genetically-programmed altruism.

Gays are designed by nature
to help us be kind to one another,

like Ellen DeGeneres says.

(Laughter)

So, E. O. Wilson,

probably the greatest evolutionary
biologist since Darwin himself,

says homosexuality gives advantages
to the group by specialized talents

and unusual qualities of personality.

So, a society that condemns
homosexuality harms itself.

So, what does professor Wilson mean
by "unusual qualities of personality"?

Well, let me tell you
about our dear family friend Jenny.

She is 35, single, straight.

She was telling us she is looking
for a man who's smart and funny,

who's sensitive, who's a good listener.

And she says she occasionally
meets a guy like that,

but she complains, "You know,
he usually has a boyfriend already!"

(Laughter)

So, although people tend to obsess over
what gays do or don't do in a bedroom,

it's really this distinctive personality
and a strong intellect

that are more critical,
from evolution's perspective.

So, scientific studies do indeed show

that people in the sexual minority
tend to be intelligent,

particularly when it comes
to emotional intelligence.

So, this study showed

that boys and girls who scored
in a very bright IQ range

were twice as likely
to be homosexual as adults

as those children who scored
in the low to average range.

And, among gay males,
on psychological testing,

gay males tend to score higher
in metrics of compassion and cooperation,

and lower in metrics of hostility.

So, if Michelangelo had been straight,

he might have just wallpapered
the Sistine Chapel.

(Laughter)

Songwriter Sam Austin says,

"Homosexuality is God's way of ensuring

the truly gifted aren't
burdened with children."

(Laughter)

But today, in the US, about 2 out of every
25 people are in the sexual minority.

Diversity is nature's secret weapon.

If all males were gay,
that would be a problem,

but if all males were warriors,
we'd always be at war.

The recipe for a successful human culture

is a synergy of many 
different ingredients.

Homosexuality is like a catalyst

to help emotionally connect
groups of people together.

For heterosexuals, to disapprove of gays

is kind of like the white flour
in bread disapproving of the yeast.

So, if your genome is your hardware,
epigenetics is your software.

You have many different DNA programs
downloaded on your DNA,

and epigenetics chooses
from among these to determine

which version of you actually is
the best fit for the environment.

So, ants, you probably didn't know it,
but are another highly social species

that have epigenetic mechanisms
very similar to humans.

These two are identical twin sisters, huh?

Even though their DNA sequences
are exactly the same,

this one, the worker,

is a brainy little scurrier
who goes out looking for food,

whereas the one on the right, the soldier,

is obviously a brawny one
to fight off enemies.

So, the queen ant
epigenetically orchestrates this

by placing different epigenetic tags
on the developing ants.

So -

she places tags 
when the colony is under attack

to uncoil the DNA and light up
the genes to make the soldier,

but when the colony is hungry,
she puts different tags to uncoil the DNA

and epigenetically create
the conditions for the worker.

So, in this way, the epigenetics -

the dynamic power of epigenetics
changes our genetic expression,

so that we're born with traits
that allow us and our families

the best chance to succeed
in the current conditions.

So, you probably have
gay genes in your DNA,

but, unless they were turned on
in your mother's womb,

they remain coiled up and silent.

A recent groundbreaking
study from UCLA found

that, by looking at a group of men,
some gay, some straight,

and looking at epigenetic tags
in nine different sites,

they could predict with 70% accuracy
their sexual orientation.

So, what conditions in the uterus
turn on those gay genes?

So, for a male,

your chances of homosexuality
increase in proportion

to the number of previous baby boys
who inhabited your mother's uterus.

So, for every older
biological brother you have,

your chances of being born gay go up 33%.

Long before we invented the pill,

nature devised homosexuality
as a prescription for birth control.

After four straight, heterosexual males,
nature says, "Enough already!,"

and the mom's immune system
switches on the epigenetic switch

so a gay male is born into the family.

This one will not be overburdening
the clan with yet more mouths to feed

in the next generation
- sometimes more isn't better -

and he's not going to be
killing his brother

in a fight over who gets the girl.

Thankfully, the sexual minority
these days have many options

for having kids of their own,

and I have a hunch my gay son
may bless us with grandchildren

before our three straight children do.

So, another gene,
this one on the X chromosome,

is called a "male-loving gene,"

because, when it shows up in a female,

she tends to mate early
and have a lot of kids,

but, when the male-loving gene
shows up in a male,

it predisposes to homosexuality.

So, this is another gene
that balances a family

destined to have a large brood
of kids and grandkids

with an occasional gay son whose natural
tendency to promote togetherness

could improve the chances of survival
for the whole family.

Now, I apologize.

We have a lot more science about
sexual orientation in men than in women,

so this talk is mostly about gay males.

Though, I have no doubt

that female homosexuality
is also a natural variation

that is advantageous
for the family and the community.

But Jimmy has no older brothers.

Why is he gay?

So, when Joan was pregnant with him,

we discovered a large cancer
growing in her chest.

Metastasis in the neck.

It was a scary time.

She had radiation therapy to her chest

while Jimmy was still
in the third trimester.

It was a rocky start for little Jimmy.

Miraculously, they both survived
and are in great health today.

But, in fact,

severe prenatal stress
does predispose to homosexuality.

In this study, 37% of gay males

reported their mothers
suffered severe prenatal stress

compared to only 3%
of heterosexual males' moms.

This is kind of like the queen ant,

where the mom is placing
epigenetic markers on the baby

to change his identity to help
the future welfare of the family.

It's as if the mom was saying,
"I'm in trouble here.

I need a kind and clever ally
to help me hold this family together."

So, to summarize,

if the family is flushed
with plenty of kids

and/or it's a stressful place and time,

nature occasionally flips
these epigenetics switches

to turn on the gay genes.

This alters brain development,

that changes sexual orientation
and also improves emotional intelligence.

I have no doubt that Jimmy was born gay.

Here's his first birthday party.

(Laughter)

When he was three, he said, "Mommy,
when I grow up, I want to marry Daddy."

(Laughter)

Now, some parents send their kid away,
you know, well-meaning parents,

to a conversion camp 
to pray away the gay.

You might as well send the kid to a camp

to convert his eye color
from brown to blue.

Not happening!

But Jimmy is like social glue
holding our family together.

You know, whether his brother Evan
gets beat up in a bar fight,

or his sister Caroline
gets dumped by a boyfriend,

or his sister Kathleen gets busted
for plagiarizing Wikipedia -

(Laughter)

they know Jimmy's made them feel

like they belong to something
bigger than their problems.

So, storytelling is the great
survival skill of the Irish,

and, right here in Dublin, 162 years ago,

one of your finest storytellers was born:

Oscar Wilde.

Oscar ran away to the University of Oxford

where he met a young poet
named Bosie Douglas.

Their long-standing 
openly gay relationship

infuriated and humiliated
Bosie's father, Lord Queensburry -

I'm not making this up -

(Laughter)

who was so mad that he eventually
had Oscar arrested for gross indecency,

thrown into a dungeon
for two years of hard labor.

Oscar died three years later, a young man.

Oscar wrote, "Always forgive your enemies.
Nothing annoys them so much."

(Laughter)

But these days, open homophobia is being
replaced by more of a subtle heterosexism

where people in the sexual minority

are often considered 
second-class citizens.

Boy George says, "There's this illusion

that homosexuals have sex
and heterosexuals fall in love.

That's completely untrue.
We all want to be loved."

I agree: among all the things in life
it'd be hardest to live without,

love would come first.

But indoor plumbing and toilet paper
would be pretty high up there too, right?

(Laughter)

I want to tell you about one more study,

this one a heartbreaking,
nationwide study, from the US,

that looked at US teens, and they found
that those in the sexual minority

were twice as likely to be bullied,

five times more likely
to have attempted suicide.

Twenty-nine percent of gay teens
had tried to kill themselves.

These days, around the world,
in many countries,

it's illegal to have same-sex
physical intimacy.

In many countries,
it's punishable by death.

In the red countries,
it's punishable by imprisonment.

In India, the law states 
14 years to life,

because "homosexuality
is against the order of nature."

Except that it's not!

Nature prescribes homosexuality
at specific times and places,

and endows these people
with special traits

that help the people around them flourish.

What is against the order of nature

is the ongoing persecution
of the sexual minority.

These are not confused or defective people

that need to be cured,
or punished, or ostracized.

They need to be accepted,

for who they are, and embraced.

They make us better.

If you had told me 30 years ago,
as I held my baby boy,

that he would grow up to be gay,

I would have been devastated,

but looking back, I see Mother Nature
knew what she was doing!

Her clairvoyant intelligence,
forged during eons of evolution,

instinctively knew my family would need
the advantages of a gay son.

Now, admittedly,

the science of homosexuality
is still in it's infancy,

but as his father,
what I can tell you for sure

is that Jimmy is exactly
who he was meant to be,

and my family is stronger and happier
because he's in our clan.

How about you?

Can you set sex aside?

Realize gay men and gay women
are essential to humanity?

We're like the ants.

It's in our diversity where we find
our collective strength.

Thank you.

(Applause) (Cheers)