Secular Evidence
Behavioral genetics has proven that personality, temperament, and even moral intuitions are substantially heritable. You didn't choose your nature. You didn't design your desires. The genome that shapes who you are was written before you drew your first breath—and it points to an Author.
Before we connect this to anything theological, let's sit with what scientists have discovered. Twin studies—the gold standard of behavioral genetics—have spent decades tracking identical twins raised apart from birth. What they've found is neither new nor controversial in the scientific community. It's simply stunning.
The Minnesota Twin Study
In 1990, Thomas Bouchard and his team at the University of Minnesota published one of the most comprehensive studies ever conducted. They tracked identical twins separated at birth—some who never even knew each other existed—and measured everything: personality traits, values, emotional reactivity, even occupational interests.
The result? Correlations of .50 to .67 across personality dimensions. Twins raised in completely different families, different states, different socioeconomic conditions showed personality similarity that stunned researchers. One pair of twins—separated at birth—both became firefighters. Another became electricians. Both arrived at their professions independently, shaped by genetics they shared but upbringing they didn't.
This wasn't anomaly. It was the opening door to a massive body of research that followed.
Heritability estimates from Bouchard & McGue (2003), Psychological Bulletin. These represent the proportion of variation in each trait across populations that can be attributed to genetic differences.
The Big Five personality traits—the framework used by virtually every personality researcher on earth—are all substantially heritable. You didn't choose to be cautious or bold. You didn't decide whether you'd be naturally analytical or intuitive. You didn't select your emotional baseline from a menu of options. These were written into you before you had any say in the matter.
Even the tendency toward religious belief—your openness to the sacred, your inclination toward spiritual conviction—is approximately 40% heritable. Some people are born with temperaments naturally open to transcendence. Others are born more skeptical. Neither chose their starting point.
Jonathan Haidt's decades of research on moral cognition reveal that the way you instinctively judge right and wrong—which moral values feel sacred to you, which feel negotiable—is partially shaped by genetic predisposition. Your conscience is not a blank slate.
Jerome Kagan's longitudinal studies showed that temperament—whether a child is naturally inhibited or bold, cautious or risk-seeking—is visible from infancy and remains predictive across the lifespan. By age two, you could already see who you would become.
And here's the part most people don't think about: your genome shaped not just who you are, but your capacity to choose, the kinds of decisions you're drawn toward, the values that resonate in your soul. It shaped your temperament—and your temperament shaped your desires. And your desires shape what you choose.
Here's where it gets uncomfortable. Because the science of genetics isn't just about personality traits in a vacuum. It's about how genetics shape everything downstream from you.
Your genes shaped your temperament. Your temperament shaped your early social experiences. Those experiences shaped your beliefs. Your beliefs shaped what you valued. What you valued shaped what you desired. What you desired shaped your choices. And your choices—the ones you felt like you freely made—were downstream from a causal chain that began with a genome you didn't write.
Consider someone with a genetic predisposition toward openness and spiritual curiosity. That temperament puts them in certain social circles. Those circles expose them to certain ideas. Those ideas resonate in a particular way because of their underlying temperament. They have a spiritual experience. They become a believer. Later, they say: I chose God.
But trace the causal chain backward. Where does it actually begin? With their choice? Or with a genetic predisposition they never chose, which made them receptive to truths they otherwise might have rejected?
Now consider someone with a genetic predisposition toward skepticism, toward systematic thinking, toward distrust of authority. That temperament leads them to question what others accept. It makes them resistant to emotional appeals. It makes them demand proof. Years later, they encounter the gospel. But their genetic temperament—the very architecture of how they think—makes them resistant to faith. They say: I don't believe.
Did they choose their skepticism? Or were they born skeptical? And if they were born skeptical, and that skepticism made them resistant to God, and then God somehow broke through that resistance and made them believe—who did the work?
There's a powerful secular argument that appears on this site called the Billion Decisions argument. The idea is this:
You are the product of a billion decisions made by people you never met, in places you never went, at times before you were born. Your parents met because their parents lived in certain towns. Those towns existed because of historical events centuries ago. A thousand tiny choices by a thousand dead people created the exact circumstances that produced you. If even one of those decisions had gone differently, you would not exist. That is not chance. That is determination. Your existence is the product of a determined causal chain stretching back through history.
But genetics adds another layer to this argument. Not only were you the product of a billion decisions made by others. You were also the product of a genome that was determined by those same historical forces. Your personality, your temperament, your inclinations—all of it was already written into the code before you took your first breath.
Scripture saw this thousands of years ago:
Acts 17:26 — "From one man he [God] made all the nations, that they should inhabit the whole earth; and he marked out their appointed times in history and the boundaries of their lands."
God didn't just decide where you would live. He decided when. He marked out the appointed time of your life, and that appointed time includes your genetic code, your temperament, your predispositions, the very nature of your capacity to choose.
Psalm 139:13-16 — "For you created my inmost being; you knit me together in my mother's womb... All the days ordained for me were written in your book before one of them came to be."
The Psalmist doesn't just say God knows you. He says God knit you together. He shaped the very fabric of your being—not just your circumstances, but your nature itself. And he did it according to a plan written before you existed.
The Bible doesn't speak the language of behavioral genetics. It doesn't use words like "heritability" or "temperament." But it speaks the truth that genetics confirms: you are not self-authored. Your nature was chosen for you. And that nature shapes who you become.
Jeremiah 1:5 — "Before I formed you in the womb I knew you, before you were born I set you apart."
God didn't just know Jeremiah would exist. He knew who Jeremiah would be. He set him apart for a purpose. That knowledge preceded Jeremiah's birth, his choices, his will. It was prior to all of it.
Romans 9:11 — "Yet, before the twins were born or had done anything good or bad—in order that God's purpose in election might stand not by works but by him who calls—she was told, 'The older will serve the younger.'"
This is the passage about Jacob and Esau. Paul's point is radical: God made His choice about these two men before they were born, before they had done anything, before they had made any choices. Their births weren't accidents. Their natures weren't neutral. They were predestined, before they existed, according to God's purpose.
Galatians 1:15-16 — "But when God, who set me apart from my mother's womb and called me by his grace, was pleased to reveal his Son in me so that I might preach him among the Gentiles..."
Paul doesn't say God called him after he was born. He says God set him apart from conception. God's calling was not a response to Paul's choice. It preceded his existence. It shaped the very nature of who Paul would become.
The Bible teaches what behavioral genetics now confirms: before you were born, you were already known. Before you drew your first breath, your nature was already determined. You are not self-created. Someone created you—and they created you with intention.
Now here's where the arguments converge in a way that's breathtaking. If genetics shaped your personality, your temperament, your emotional reactivity, your openness to experience—and all of these influence whether you're drawn toward faith or repelled from it—then what does that tell us about the claim: "I chose God by my own free will"?
Scripture is unmistakably clear about this:
Ephesians 2:8-9 — "For by grace you have been saved, through faith—and this is not from yourselves, it is the gift of God—not by works, so that no one can boast."
The text doesn't say grace is a gift. It says your faith itself is a gift. The very faith by which you believe—that is grace. That is something done to you, not by you. And if faith is a gift, then taking credit for it is like a man opening a present and boasting about his generosity in buying himself a gift.
Behavioral genetics shows us why. If your capacity for faith—your openness, your ability to receive truth, your willingness to trust—is substantially shaped by genetics you didn't choose, then how can you claim credit for exercising it?
You can claim credit for something only if you authored it. You only authored something if you chose it. You only chose it if you had the capacity to choose otherwise. But if your capacity itself is determined by genetics that you inherited—that you received—then your "choice" to believe is not something you originated. It's something you were made capable of by something prior to you.
In other words: your faith is a gift. Not primarily a gift from your parents or your culture or your circumstance. A gift from God—the God who authored your genome, who knit you together in your mother's womb, who knew you before the creation of the world, and who shaped the very nature of your capacity to believe.
If you believe you chose God by your own free will, you are claiming that you generated faith from within yourself. But if your genetic predisposition—which you didn't choose—shaped your openness to faith, then you didn't generate it. You received it. Someone gave you a temperament that made faith possible. That someone was God. And if God gave you the capacity to believe, and then brought you to believe, how much of that "choice" was actually yours?
Here's the liberating truth that emerges from all of this: you were not an accident, and you were not self-created.
Secular science confirms what Scripture has always taught: before you existed, your nature was determined. The genome that shapes who you are was written into the code before you took your first breath. That code came from your parents. Their code came from theirs. But trace it back far enough, and you confront a reality that science cannot explain and yet cannot deny: there is a design here. There is an intention.
You are not the author of your nature. That makes you a creation, not a creator. And a creation points to a Creator. That Creator—the God who knit you together, who knew you before the world was made, who shaped the very architecture of who you would become—that God chose you. Not because of anything you did. Not because of any choice you made. But because He determined it. He ordained it. He elected you.
And if God knew you from the beginning, if He shaped you from conception, if He determined the very nature of your capacity to respond to Him—then when He calls you to Himself, it is not an interruption of your autonomy. It is the fulfillment of His intention. It is not something you choose. It is something you discover: you were always meant to be loved by God, and you were created capable of receiving that love.
If you're reading this and feeling the weight of it—if you're realizing that you can't take credit for your own faith, that you are not the author of your salvation—you may feel unsettled. Untethered. And that's okay. This is the moment when God often does His most tender work. Not by condemning your powerlessness, but by filling it. By showing you that the God who created you did not leave you in your inability. He came toward you. He drew you. He will not let you go. Read this next.